Peltogynoids contributing to discoloration in Peltogyne mexicana heartwood

Peltogynoids contributing to discoloration in Peltogyne mexicana heartwood | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Peltogynoids contributing to discoloration in Peltogyne mexicana heartwood Yusuke Taga, Kosei Yamauchi, Tohru Mitsunaga This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4759481/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 15 Nov, 2024 Read the published version in Wood Science and Technology → Version 1 posted 10 You are reading this latest preprint version Abstract Four new peltogynoid monomers ( 3 , 7 , 10 , 11 ), a new peltogynoid dimer ( 9 ), and two new flavanones ( 5 , 6 ) were isolated from the heartwood of Peltogyne mexiacana , along with two known peltogynoids ( 1 , 4 ) and two known aldehydes ( 2 , 8 ). The structures of the isolated compounds were determined using NMR and MALDI-TOF MS analysis. The discoloration of the methanol solutions of the isolated peltogynoids and flavanones was examined by exposing them to room light in the air. The methanol solutions of (+)-peltogynol ( 1 ) and (+)-mopanol ( 4 ) discolored to reddish and bluish purple, respectively. After discoloration, the b* values of these compounds decreased significantly from 12.1 and 19.1 to -0.7 and − 1.8, respectively. These precursors of pigment compounds 1 and 4 have a catechol moiety in the B ring, and a hetero-six-membered ring (D ring) connecting the B and C ring of flavan-3,4-diol via an oxyethylene bridge, which is similar to the structure of leucoanthocyanidin. These results led to the hypothesis that the metabolized pigment compounds have anthocyanidin-like structures with peltogyne skeleton. flavonoid Peltogyne mexicana peltogynoid pigment precursor Figures Figure 1 Figure 2 Introduction Peltogyne mexicana is native to neotropical regions, including Guiana and Brazil, and grows a height of 30–40 m (Janet et al. 2023 ). The heartwood of Peltogyne trees is well known to metabolize characteristic flavonoid, peltogynoids (S. E. Drewes and D. G. Roux 1967). This group of flavonoids has a hetero-six-membered ring (D ring) that connects the B and C rings of flavan-3-ol via an oxyethylene bridge (Mathew et al. 2023 ). In the first isolation report on peltogynoids, (+)-peltogynol was isolated from P. porphyrocardia Griseb . ex Benth , and its absolute configuration was determined to be 2 R , 3 S , 4 R (G. M. Robinson and R. Robinson 1935 ; Hassall and Weatherston 1965 ). Currently, various peltogynoids have been isolated from various species, including Peltogyne , Colophospermum , and Cassine (W. R. Chan et al. 1958 ; E. Drewes et al. 1991 ; Daneel et al. 2003 ). Peltogynoid shows variety of pharmacological activities, such as anti-inflammatory activity of myrtinol E isolated from Backhousia myrtifolia (Mathew et al. 2023 ), cytotoxicity against cancer cells of bougainvinone G isolated from Bougainvillea spectabilis (Do et al. 2016 ), and kinase inhibitory activity of acanilol B isolated from Acacia nilotica (Ahmadu et al. 2010 ). P. mexicana heartwood, which contains peltogynoids, is well known for its purple discoloration, hence, it is commonly referred to “Purple heart”. The heartwood gradually turns bright purple after its surface is exposed to air and sunlight, while it shows pale yellow immediately after harvesting or injury (Paulina et al. 2019 ; Janet et al. 2023 ). Because of this unique purple color and the high durability as wood material (Marcos et al. 2021 ), P. mexicana heartwood has a high market value and is used as high-grade wood material in a wide range of industries. The phenomenon in which the color of heartwood changes after being cut down has been reported for various species used for high-end desks and furniture, including Caesaplinia sappan and Millettia pendula. Regarding the heartwood of Caesaplinia sappan , called sappan wood, brazilin is autoxidized to brazilein and appears red in color (Kim et al. 1997 ; De Oliveira et al. 2002 ). The heartwood of Millettia pendula turns dark purple after being harvested. This heartwood contains 7,3',4'-trihydroxy-6'-methoxyisoflav-3-ene, which forms quinone methide when oxidized, and turns dark purple in color (Mitsunaga et al. 1987a , b ). As shown in these examples, discoloration in heartwood often results from oxidative reactions (Laver and Arvey 1996 ; Chang et al. 2000 ). In P. mexicana , the production of red compounds was observed when peltogynoids were heated under acidic conditions (G. M. Robinson and R. Robinson 1935 ; Brandt and Roux 1979 ). In another report, peltomexicanin, in which the B ring exhibits a quinone methide form, was isolated as a heartwood pigment compound (Gutiérrez-Macías et al. 2016 ). However, no research has focused on the precursors to the pigment compounds involved in this discoloration. In this study, isolation of various peltogynoids and other flavonoids from P. mexicana heartwood was conducted to identify compounds responsible for heartwood discoloration as precursors. Materials and methods 4.1 General Experimental procedures All of color measurement in this study was conducted using Color analyser TES-3250 (TES Electrical Electronic Corp. Taiwan). High-performance liquid chromatography (HPLC) analysis was performed using MD-2018 photodiode array detector (JASCO, Japan) equipped with a Sunniest C18 reversed phase column (5 mm × 250 mm length, ChromaNik Technologies Inc.) at flow rate of 1.0 mL/min, detection wavelength of 190-700 nm, and oven temperature of 35ºC. Regarding the mobile phase, 0.05% TFA aq. (A) and methanol (B) were used as mobile phases. The eluant was applied as a linear gradient elution for 50 min from 20% to 80% of solvent B. Preparative HPLC was conducted using a set of LC-6AD system (SHIMAZU, Japan) equipped with a Inertsil ODS-3 column (5 μm, 20 × 250 mm, GL Sciences, Japan) at flow rate of 9.0 mL/min. Nuclear magnetic resonance (NMR) spectra were recorded on a JEOL JNM ECA-600 (JEOL, Japan), and Bruker Biospin AVANCE III 800 (bruker, USA). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) spectra were measured using a Shimadzu AXIMA resonance spectrometer equipped with a nitrogen laser (λ=337 nm). Electronic circular Dichroism (ECD) spectra were recorded on a J-820P spectrometer (JASCO, Japan) using 1 mm path precision cells. 4.2 Computational details For compounds with chiral centers, the absolute configuration was determined by a computational ECD calculation. All calculations were performed by the Gaussian16W program package(M.J. Frisch et al. 2016). ECD calculation was performed by the TD-SCF method at the WB97XD/6–31+G(d, p) level in methanol as solvent. The final ECD spectra were obtained according to the Boltzmann-calculated contribution of each conformer by SpecDis(T. Bruhn et al. 2017). The calculated experimental data were compared with the ECD spectra. 4.3 Plant materials and extraction Wood materials of Peltogyne mexicana heartwood was obtained from a timber dealer (Yamagataya Industry Co., Ltd., Japan). Heart wood (600 g) was crushed to powder states and extracted with 2 L of methanol, then dried methanol extract was partitioned successively twice with n -hexane, diethyl ether, ethyl acetate, and methanol using 2 L each. Each soluble part was evaporated and all of extract procedure was conducted under dark condition. 4. 4CIE LAB parameter The color of methanol extract, each soluble part, and isolated flavonoids were evaluated using CIE LAB parameters ( a* , b* , L* ). Besides, the values of h* , , , ,, and were calculated from CIE LAB parameters (Supap et al. 2012; Jung and Sato 2013). Discolorations in this study were evaluated by a changing these parameters. 4. 5 Light exposure behavior of extract and soluble parts A 5 mg of methanol extract or each soluble part was dissolved with 1.5 ml of methanol and removed into a small vial. The degree of discoloration was evaluated by exposure the vials to a room light (approximately 470 lx) in the air at room temperature for 24 hours. Refer to measuring the color, filter paper chip cut into a circle shape with a diameter of 1.5 cm, then impregnated in methanol extract and each soluble parts part before and after exposure, and the values of a* , b* , and L* were measured using a color anolyser. 4. 6 Compounds isolation All separation procedure procedures were monitored by TLC and HPLC profiles. The part of diethyl ether soluble part (10.0 g) was fractionated on an open silica gel column chromatography (80 mmφ×600 mm) and eluted with ethyl acetate : n -hexane (4 : 6, v/v) to obtain four subfractions (EFr.1-4). Subfraction EFr.3 (2 g) was further fractionated on an open silica gel column chromatography (70 mmφ×300 mm) and eluted with methanol : chloroform (3 : 7, v/v) to obtain five subfractions (EFr.3-1 – 3-5). EFr.3-5 (147.3 mg) was subjected to open ODS-silica gel column chromatography (40 mmφ×150 mm) and eluted with 70 % methanol aq. to yield 1 (19.1 mg). 4 (15.6 mg), and 10 (4.0 mg) were purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min] from EFr.3-4 (47.0 mg). Subfraction EFr.2 (197.1 mg) was further fractionated on an open silica gel column chromatography (60 mmφ×300 mm) and eluted with methanol : chloroform (2 : 8, v/v) to obtain four subfractions (EFr.2-1 – 2-4), then 2 (3.5 mg) was purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min] from EFr.2-1 (22.5 mg). EFr.2-2 (129.4 mg) was subjected to open silica gel column chromatography (30 mmφ×320 mm) and eluted with methanol : chloroform (1 : 9, v/v) to obtain four subfractions (EFr.2-2-1 – 2-2-4). then 3 (12.5 mg), 5 (2.7 mg), and 6 (3.2 mg) were purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min] from EFr.2-2-2 (53.2 mg). The part of ethyl acetate soluble part (1.0 g) was fractionated on an open silica gel column chromatography (80 mmφ×600 mm) and eluted with ethyl acetate : n -hexane (2 : 8, v/v) to obtain three subfractions (AFr.1-3). Subfraction AFr.2 (392.9 mg) was further fractionated on an open silica gel column chromatography (35 mmφ×350 mm) and eluted with ethyl acetate : n -chloroform (8:2, v/v) to obtain 3 subfractions (AFr.2-1 – 2-3), then 7 (8.7 mg) was purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min] from EFr.2-3 (23.0 mg). 8 (2.6 mg) was purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min] from EFr.2-1 (8.1 mg). Subfraction AFr.3 (80.7 mg) was further fractionated on an open silica gel column chromatography (40 mmφ×300 mm) and eluted with methanol : n -chloroform (3 : 7, v/v) to obtain 8 subfractions (AFr.3-1 – 3-8), then 9 (4.4 mg) was purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min] from EFr.3-8 (23.0 mg). The part of ethyl acetate soluble part (3.3 g) was fractionated on an open LH-20 gel column chromatography (50 mmφ×300 mm) and eluted with methanol : chloroform (5 : 5, v/v) to obtain four subfractions (LHFr.1-4). Subfraction LHFr.3 (150.6 mg) was further fractionated on an open ODS-silica gel column chromatography (25 mmφ×210 mm) and 60 % methanol aq. to obtain four subfractions (LHFr.3-1 – 3-4), then 11 (6.6 mg) was purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min] from LHFr.3-3 (20.4 mg). Structures of isolated compounds were determined by the NMR analysis and the MALDI-TOF MS analysis. For steric compounds, ECD measurement was performed to determine their absolute configuration. 4. 7Spectroscopic data (+)-Peltogynol ( 1 ) Pale yellow crystal; ECD ( c 0.3 mM, methanol) λ max (Δ ε ): 235.0 (+20.41), 289.0 (+4.50); 1 H-NMR (ppm, 600 MHz, methanol- d 4 ) 3.52 (3-H, 1H, dd ), 4.74 (1”-H, 1H, d ) 4.76 (4-H, 1H, d ), 4.77 (2-H, 1H, d ), 6.35 (8-H, 1H, d ), 6.49 (6-H, 1H, dd ), 6.56 (5’-H, 1H, s ), 7.09 (2’-H, 1H, s ), 7.35 (5-H, 1H, d ); 13 C-NMR (ppm, 125 MHz, methanol- d 4 ) 68.3 (C-1”), 69.9 (C-4), 72.7 (C-2), 79.2 (C-3), 103.1 (C-8), 109.9 (C-6), 111.0 (C-5’), 113.4 (C-2’), 118.0 (C-4a), 124.9 (C-1’), 127.4 (C-6’), 130.1 (C-5), 145.0 (C-4’), 145.9 (C-3’), 155.9 (C-8a), 158.7 (C-7); MALDI-TOFMS m/z 325.0692 [M+Na] + (calculated for 325.0688, C 16 H 14 NaO 6 ) 2, 4-dihydroxybenzaldehyd ( 2 ) White crystal; 1 H-NMR (ppm, 600 MHz, acetone- d 6 ) 6.26 (3-H, 1H, d ), 6.43 (5-H, 1H, dd ), 7.48 (6-H, 1H, d ), 9.67 (7-H, 1H, s ); 13 C-NMR (ppm, 125 MHz, acetone- d 6 ) 103.2 (C-3), 109.9 (C-5), 116.2 (C-1), 136.7 (C-6), 165.6 (C-2), 167.3 (C-4), 195.5 (C-7); MALDI-TOFMS m/z 161.0216 [M+Na] + (calculated for 161.0215, C 7 H 6 NaO 3 ) 4 R -methoxymopanol ( 3 ) Pale yellow crystal; ECD ( c 0.3 mM, methanol) λ max (Δ ε ): 212.0 (+20.96), 227.0 (+5.79); 1 H-NMR (ppm, 600 MHz, acetone- d 6 ) 3.60 (-OCH 3 , 3H, s ), 3.69 (3-H, 1H, dd ), 4.55 (4-H, 1H, d ), 4.79 (1’’-H, 1H, d ), 4.80 (2-H, 1H, d ), 4.92 (1’’-H, 1H, d ), 6.34 (8-H, 1H, d ), 6.49 (6-H, 1H, dd ), 6.84 (5’-H, 1H, d ), 6.99 (6’-H, 1H, d ), 7.23 (5-H, 1H, d ); 13 C-NMR (ppm, 125 MHz, acetone- d 6 ) 58.3 (-OCH 3 ), 65.2 (C-1’’), 65.2 (C-1’’), 72.6 (C-2), 77.5 (C-3), 78.8 (C-4), 103.3 (C-8), 110.0 (C-6), 114.6 (C-5’), 115.5 (C-4a), 117.8 (C-6’), 123.1 (C-2’), 125.6 (C-1’), 130.4 (C-5), 141.0 (C-3’), 144.3 (C-4’), 156.4 (C-8a), 158.9 (C-7); MALDI-TOFMS m/z 339.0842 [M+Na] + (calculated for 339.0845, C 17 H 16 NaO 6 ). All NMR data were shown in Table 1. (+)-mopanol( 4 ) Yellow crystal; ECD ( c 0.3 mM, methanol) λ max (Δ ε ): 211.0 (+15.31), 228.0 (+4.51); 1 H-NMR (ppm, 600 MHz, acetone- d 6 ) 3.52 (3-H, 1H, dd ), 4.74 (1”-H, 1H, d ), 4.78 (4-H, 1H, d ), 4.79 (2-H, 1H, d ), 5.07 (1”-H, 1H, d ), 6.36 (8-H, 1H, d ), 6.49 (6-H, 1H, dd ), 6.84 (5’-H, 1H, d ), 6.99 (6’-H, 1H, d ), 7.36 (5-H, 1H, d ); 13 C-NMR (ppm, 125 MHz, acetone- d 6 ) 65.4 (C-1”), 65.4 (C-1”), 70.0 (C-4), 72.6 (C-2), 78.6 (C-3), 103.1 (C-8), 109.9 (C-6), 114.6 (C-5’), 117.8 (C-4a), 117.8 (C-6’), 123.2 (C-2’), 125.7 (C-1’), 130.0 (C-5), 141.0 (C-3’), 144.3 (C-4’), 155.8 (C-8a), 158.7 (C-7); MALDI-TOFMS m/z 325.0689 [M+Na] + (calculated for 325.0688, C 17 H 16 NaO 6 ) 3 R -methoxy-(+)-butin ( 5 ) Colorless crystal;ECD ( c 0.3 mM, methanol) λ max (Δ ε ): 324.4 (+3.15), 292.6 (-1.69), 268.8 (+1.19), 233.2 (+4.98), 217.2 (+6.92); 1 H-NMR (ppm, 600 MHz, methanol- d 4 ) 3.31 (-OCH 3 , 3H, s ), 3.73 (3-H, 1H, d ), 5.31 (2-H, 1H, d ), 6.37 (8-H, 1H, d ), 6.52 (6-H, 1H, dd ), 6.75 (5’-H, 1H, d ), 6.82 (6’-H, 1H, d ), 7.01 (2’-H, 1H, d ), 7.72 (5-H, 1H, d ); 13 C-NMR (ppm, 125 MHz, methanol- d 4 ) 59.1 (-OCH 3 ), 82.4 (C-2), 82.4 (C-3), 103.6 (C-8), 112.1 (C-6), 113.3 (C-4a), 115.8 (C-5’), 115.9 (C-2’) 120.0 (C-6’) 129.0 (C-1’) 130.3 (C-5), 146.1 (C-4’), 146.6 (C-3’), 165.0 (C-8a), 166.8 (C-7), 190.6 (C-4); MALDI-TOFMS m/z 325.0688 [M+Na] + (calculated for 325.0688, C 16 H 14 NaO 6 ). All NMR data were shown in Table 2. 3 S -methoxy-2 S -liquiritigenin ( 6 ) Pale yellow crystal; ECD ( c 0.3 mM, methanol) λ max (Δ ε ): 331.4 (+1.31), 302.4 (-1.54), 236.0 (+2.13), 213.6 (+6.28); 1 H-NMR (ppm, 600 MHz, methanol- d 4 ) 3.29 (-OCH 3 , 3H, s), 4.22 (3-H, 1H, d), 5.12 (2-H, 1H, d), 6.32 (8-H, 1H, d), 6.52 (6-H, 1H, dd), 6.82 (3'-H, 1H, dd), 6.82 (5'-H, 1H, dd), 7.33 (2'-H, 1H, dd), 7.33 (6'-H, 1H, dd), 7.71 (5-H, 1H, d); 13 C-NMR (ppm, 125 MHz, methanol- d 4 ) 60.6 (-OCH 3 ), 83.3 (C-3), 84.1 (C-2), 103.6 (C-8), 112.1 (C-6), 114.0 (C-4a), 116.2 (C-3'), 116.2 (C-5'), 129.2 (C-1'), 130.1 (C-5), 130.1 (C-2'), 130.1 (C-6'), 159.2 (C-4'), 164.8 (C-8a), 166.9 (C-7), 193.4 (C-4); MALDI-TOFMS m/z 309.0739 [M+Na] + (calculated for 307.0739, C 16 H 14 NaO 5 ). All NMR data were shown in Table 3. 2 S , 3 S - peltogynone ( 7 ) Colorless crystal; ECD ( c 0.3 mM, methanol) λ max (Δ ε ): 324.6 (+2.7), 292.8 (-1.5), 270.6 (+1.1), 233.0 (+4.8), 216.8 (+6.7); 1 H-NMR (ppm, 600 MHz, methanol- d 4 ) 4.37 (3-H, 1H, d ), 4.56 (2-H, 1H, d ), 4.80 (1’’-H, 2H, d ), 6.46 (8-H, 1H, d ), 6.50 (3’-H, 1H, s ), 6.56 (6-H, 1H, dd ), 7.06 (6’-H, 1H, s ), 7.75 (5-H, 1H, d ); 13 C-NMR (ppm, 125 MHz, methanol- d 4 ) 69.4 (C-1’’), 76.4 (C-2), 77.8 (C-3), 103.9 (C-8), 111.3 (C-3’), 112.3 (C-6), 113.1 (C-6’), 114.3 (C-4a), 124.1 (C-1’), 126.8 (C-2’), 130.2 (C-5), 146.0 (C-4’), 147.1 (C-5’), 164.5 (C-8a), 166.8 (C-7), 191.3 (C-4); MALDI-TOFMS m/z 323.0527 [M+Na] + (calculated for 323.0531, C 16 H 14 NaO 6 ). All NMR data were shown in Table 4. syringaldehyde ( 8 ) White crystal; 1 H-NMR (ppm, 600 MHz, methanol- d 4 ) 3.98 (-OCH 3 , 6H, s ), 7.15 (2, 6-H, 2H, s ), 9.82 (7-H, 1H, s ); 13 C-NMR (ppm, 125 MHz, methanol- d 4 )56.5 (-OCH 3 ), 106.7 (C-2), 106.7 (C-6), 147.3 (C-1), 164.1 (C-3), 164.1 (C-4), 164.1 (C-5), 190.7 (C-7); MALDI-TOFMS m/z 205.0471 [M+Na] + (calculated for 205.0476, C 9 H 10 NaO 4 ) ( +)- mopanol B-(4β→6’’’)-(+)-molanol ( 9 ) Colorless crystal; ECD ( c 0.3 mM, methanol) λ max (Δ ε ): 217.0 (+30.9), 206.4 (-42.3); 1 H-NMR (ppm, 600 MHz, acetone- d 6 ) 3.55 (3’’’-H, 1H, dd ), 4.18 (3-H, 1H, dd ), 4.72 (4’’’-H, 1H, d ), 4.80 (1’’’’’-H, 1H, d ), 4.84 (4-H, 1H, d ), 4.87 (2’’’-H, 1H, d ), 4.92 (1’’-H, 1H, d ), 4.96 (1’’-H, 1H, d ), 5.00 (2-H, 1H, d ), 5.02(1’’’’’-H, 1H, d ), 6.52 (8’’’-H, 1H, s ), 6.53 (6-H, 1H, dd ), 6.56 (8-H, 1H, d ), 6.86 (5’’’-H, 1H, s ), 6.88 (5-H, 1H, d ), 6.95 (5’’’’-H, 1H, d ), 6.94 (5’-H, 1H, d ), 7.10 (6’’’’-H, 1H, d ), 7.17 (6’-H, 1H, d ); 13 C-NMR (ppm, 125 MHz, acetone- d 6 ) 39.6 (C-4), 65.4 (C-1’’’’’), 65.7 (C-1’’), 67.6 (C-2), 69.8 (C-4’’’), 72.6 (C-2’’’), 76.4 (C-3), 78.6 (C-3’’’), 103.5 (C-8), 104.3 (C-8’’’), 110.3 (C-6), 114.8 (C-5’’’’), 114.9 (C-5’), 115.0 (C-6’’’), 117.6 (C-6’’’’), 117.8 (C-6’), 118.2 (C-4a’’’), 122.7 (C-2’), 123.3 (C-2’’’’), 123.8 (C-4a), 125.8 (C-1’), 125.8 (C-1’’’’), 132.1 (C-5’’’), 132.9 (C-5), 141.0 (C-4’), 141.0 (C-4’’’’), 144.3 (C-3’), 144.3 (C-3’’’’), 154.5 (C-8a’’’), 156.5 (C-8a), 157.3 (C-7’’’), 158.2 (C-7); MALDI-TOFMS m/z 609.1369 [M+Na] + (calculated for 609.1373, C 32 H 26 NaO 11 ). All NMR data were shown in Table 5. 3-hydroxypeltogynone ( 10 ) Colorless crystal; 1 H-NMR (ppm, 600 MHz, acetone- d 6 ) 4.50 (2-H, 1H, s ), 4.87 (1’’-H, 1H, d ), 4.87 (1’’-H, 1H, d ), 6.36 (8-H, 1H, d ), 6.56 (6-H, 1H, dd ), 6.57 (3’-H, 1H, s ), 6.82 (6’-H, 1H, s ), 7.48 (5-H, 1H, d ); 13 C-NMR (ppm, 125 MHz, acetone- d 6 ) 66.0 (C-1’’), 68.3 (C-2), 99.4 (C-8), 105.7 (C-3), 111.4 (C-3’), 113.2 (C-4a), 113.2 (C-6), 115.7 (C-6’), 125.7 (C-2’), 125.9 (C-1’), 127.4 (C-5), 145.9 (C-4’), 146.8 (C-5’), 169.6 (C-8a), 174.5 (C-7), 195.3 (C-4); MALDI-TOFMS m/z 339.0478 [M+Na] + (calculated for 339.0481, C 16 H 12 NaO 7 ). All NMR data were shown in Table 6. 4-methoxypeltogynol ( 11 ) Colorless crystal; 1 H-NMR (ppm, 600 MHz, acetone- d 6 ) 3.57 (-OCH 3 , 1H, s ), 3.70 (3-H, 1H, d ), 4.54 (4-H, 1H, dd ), 4.78 (2-H, 1H, d ), 4.79 (1’’-H, 1H, d ), 4.92 (1’’-H, 1H, d ), 6.36 (8-H, 1H, d ), 6.49 (6-H, 1H, dd ), 6.57 (3’-H, 1H, s ), 7.08 (6’-H, 1H, s ), 7.22 (5-H, 1H, dd ); 13 C-NMR (ppm, 125 MHz, acetone- d 6 ); MALDI-TOFMS m/z 339.0840 [M+Na] + ( m/z 339.0845, Calculated for C 17 H 1 6 4 NaO 6 ). All NMR data were shown in Table 7. 4. 8 Effect of light exposure to isolated compounds Except for two aldehydes ( 2 , 8 ), 2 mg of each isolated compound that are peltogynoid s was dissolved in 0.5 ml of methanol and transferred into an NMR tube. Discoloration was evaluated by exposure to room light in the air for 24h. To measure the color, a filter paper chip cut into a circle with a diameter of 1.5 cm was impregnated with each methanol solvent of the isolated compounds, and the values of a* , b* , and L* before and after exposure were measured using a color meter. Results and discussion 5.1 Light exposure behavior of extract and soluble parts For the CIE LAB parameters, positive values of a* indicate redness, while negative values indicate greenness, and positive values of b* indicate yellowness, while negative values indicate blueness. If the coordinates of ( a*, b* ) are (0, 0), it is achromatic (Supap et al. 2012 ; Jung and Sato 2013 ). The results of the CIE parameter measurements for the methanol extract and each soluble part are shown in Fig. 1 a and Table S1 . At 0h of light exposure, the L* values of all soluble parts, except for the n- hexane soluble part, were + 89 to + 95, and the a* and b* values were positive, indicating that all of them ranged from orange to brown. After 48 h of light exposure, the a* values of the methanol extract, ether soluble part, and ethyl acetate soluble parts changed to positive values with Δa* 0h→24h of 6.5, 2.6, and 4.3, and the b* values changed to negative values with Δb* 0h→24h of -27.9, -14.5, and − 21.3, respectively. Meanwhile, each parameter of the n -hexane and methanol soluble parts remained almost unchanged ( Δa* 0h→24h = 0.2 and 1.5, Δb* 0h→24h = 0.0 and 0.9). Additionally, their hue values were significantly reduced ( Δh* 0h→24h = -141.7, -100.0, -127.8) and ΔE values were increased ( ΔE 0h→24h = 28.6, 15.3, 21.9). These results indicate that the methanol extract, ether soluble part, and ethyl acetate soluble part were discolored purple upon exposure to room light in the air (Fig. 1 a). These clearly show that the precursors of the pigment compounds were mainly concentrated in the diethyl ether and ethyl acetate soluble parts. 5.2 Structure determination 1 , 2 , 4 , and 8 were identified as (+)-peltogynol ( 1 ) (S. E. Drewes and D. G. Roux 1966), 2,4-dihydroxybenzaldehyde ( 2 ) (Eun-Mi et al. 2007 ), (+)-mopanol ( 4 ) (S. E. Drewes and D. G. Roux 1966), and syringaldehyde ( 8 ) (A. Ram Kumar et al. 2021 ), according to previous literature data. Among them, 2 and 8 were isolated from this species for the first time. All compounds isolated in this study are shown in Fig. 2 . 5.2.1 Structure determination of monomers Compound 3 was isolated as pale-yellow crystals. The MALDI-TOF MS analysis in the positive mode generated an [M + Na] + ion at m/z 339.0842 (calculated for C 17 H 16 NaO 6, m/z 339.0845) indicating the molecular formula C 17 H 16 O 6 (Fig.S3- 1 ). The structure was elucidated by analyzing the NMR spectra (Fig.S3- 2 to S3-6). The 1 H-NMR spectrum showed the presence of five phenyl group protons [ δ H = 7.23 (1H, d ), 6.99 (1H, d ), 6.84 (1H, d ), 6.49 (1H, dd ), and 6.34 ppm (1H, d )], four alkane protons [4.80 (1H, d ), 4.92 (1H, d ), 4.79 (1H, d ), 4.55 (1H, d ), and 3.69 ppm (1H, dd )], and one methoxy proton [3.60 ppm (3H, s )]. 13 C-NMR spectrum showed seventeen resonances, including twelve phenyl carbons [ δ C = 158.9, 156.4, 144.3, 141.0, 130.4, 125.6, 123.1, 117.8, 115.5, 114.6, 110.0, and 103.3 ppm], four alkane carbons [78.8, 77.5, 72.6, and 65.2 ppm], and one methoxy carbon [58.3 ppm]. For protonated carbon, the correspondences between the protons and carbon were determined based on the HMQC spectrum. COSY spectrum showed a coupled proton system attributed to H-5 (doublet, 7.23 ppm, J = 7.8 Hz) and H-6 (double doublet, 6.49 ppm, J = 3.0, 8.4 Hz), and H-5’ (doublet, 6.84 ppm, J = 8.4 Hz) and H-6’ (doublet, 6.99 ppm, J = 8.4 Hz). From the coupling constants and the results of COSY analysis, the five phenyl group protons were separated into a trisubstituted benzene ring consisting of H-5 (doublet, 7.23 ppm, J = 7.8 Hz), H-6 (double doublet, 6.49 ppm, J = 3.0, 8.4 Hz), and H-8 (doublet, 6.34 ppm, J = 3.0 Hz), and a tetrasubstituted benzene ring consisting of H-5’ (doublet, 6.84 ppm, J = 8.4 Hz) and H-6’ (doublet, 6.99 ppm, J = 8.4 Hz) (A ring and B ring). A continuous spin system of C-2 to C-4 was observed in the COSY correlation and a series of HMBC correlations of H-2/C-1’, C-6’, H-3/C-1’’, H-4/C-4a, C-8a, and H-1’’/C-1’ were assigned to construct the mopanol skeleton. The position of the methoxy group was determined based on the HMBC correlation of H-4/OCH 3 . Thus, the planar structure 3 was determined as 4-methoxymopanol. The relative configuration of 3 was determined based on the coupling constant of H-2 (doublet, 4.80 ppm, J = 11.4 Hz), H-3 (double doublet 3.69 ppm, J = 7.8, 9.6 Hz), and H4 (doublet, 4.55 ppm, J = 8.4 Hz) as 2,3- trans -3,4- trans . The absolute configuration of 3 was determined from its ECD spectrum (Fig. S3-7). The experimental ECD spectrum of 3 showed positive Cotton effects at approximately 212 and 227 nm. This result is in good agreement with the calculated ECD spectrum of (2 R , 3 S , 4 R )- 3 . Thus, the absolute configuration of 3 was determined to be 4 R -methoxymopanol. Compound 11 was isolated as colorless crystals. The MALDI-TOF MS analysis in positive mode generated an [M + Na] + ion at m/z 339.0840 (calculated for C 17 H 14 NaO 6, m/z 339.0845), indicating the molecular formula C 17 H 14 O 6 (Fig.S9- 1 ). The structure was elucidated based on the analysis of the NMR spectra (Fig.S9- 2 to S9-6). 11 was determined to be the structural isomer of 3 , differing in the positions of the two hydroxy groups in the B ring. The 1 H-NMR spectrum showed two singlets of H-3’ (singlet, 6.57 ppm) and H-5’ (singlet, 7.08 ppm), while H-3’ and H-5’ of 3 were detected as doublets. A series of HMBC correlation of H-1’’/C-3 and H-5’/C-2, and a downfield shift of H-4’ ( δ C = 145.0 ppm) and H-5’ (146.0 ppm) showed that 11 retained a peltogynol skeleton. Thus, the planar structure 8 was determined to be 4-methoxypeltogynol. The relative configuration of 11 was determined based on coupling constants of H-2 (doublet, 4.78 ppm, J = 9.6 Hz), H-3 (double doublet 3.70 ppm, J = 8.4, 9.6 Hz), and H-4 (doublet, 4.54 ppm, J = 8.4 Hz) as 2,3- trans -3,4- trans . ECD measurement of 11 was conducted to determine its absolute configuration, however, the Cotton effect was not observed. Therefore, only the planar structure was determined in this study. Compound 10 was isolated as colorless crystals. The MALDI-TOF MS analysis in the positive mode generated an [M + Na] + ion at m/z 339.0478 (calculated for C 16 H 12 NaO 7, m/z 339.0481), indicating the molecular formula C 16 H 12 O 7 (Fig.S8- 1 ). The structure was elucidated based on the analysis of the NMR spectra (Fig.S8- 2 to S8-6). Comparison of the spectroscopic data of 10 with 11 showed that 10 retained its mopanol skeleton. Their differences lie in the downfield shift of C-3 ( δ C = 105.7 ppm) and the change to the carbonyl region of C-4 (195.3 ppm) (See Fig.S8- 1 to 8 − 5). Thus, the planar structure 10 was determined to be 3-hydroxypeltogynone. The Cotton effect was not observed in the ECD measurement of 10 . Therefore, only the planar structure was determined in this study. Compound 7 was isolated as colorless crystals. The MALDI-TOF MS analysis in the positive mode generated an [M + Na] + ion at m/z 323.0527 (calculated for C 16 H 12 NaO 6, m/z 323.0531) indicating the molecular formula C 16 H 12 O 6 (Fig.S6- 1 ). The structure was elucidated based on the analysis of the NMR spectra (Fig.S6- 2 to S6-6). THE NMR spectrum of 7 was similar to that of 10 , differing in the presence of H-3 (doublet, 4.37 ppm, J = 11.4 Hz). This indicates that C-3 is a protonated carbon, whereas the C-3 of 10 is hydroxylated. Thus, the planar structure of 7 was determined to be peltogynone. The relative configuration of 7 was determined based on the coupling constants of H-2 (doublet, 4.56 ppm, J = 11.4 Hz) and H-3 (doublet, 4.37 ppm, J = 11.4 Hz) as 2,3- trans . The absolute configuration of 7 was determined from its ECD spectrum (Fig. S6-7). The experimental ECD spectrum of 7 showed a positive Cotton effect at approximately 325, 271, 233, and 217 nm, and a negative Cotton effect at approximately 293 nm. This result is in good agreement with the calculated ECD spectrum of (2 S , 3 S )- 7 . Thus, the absolute configuration of 7 was determined to be 2 S , 3 S -peltogynone. Compound 6 was isolated as pale yellow crystals. The MALDI-TOF MS analysis in the positive mode generated an [M + Na] + ion at m/z 309.0739 (calculated for C 16 H 14 NaO 5, m/z 309.0739), indicating the molecular formula C 16 H 14 O 5 (Fig.S5- 1 ). The structure was elucidated based on the analysis of the NMR spectra (Fig.S5- 2 to S5-6). The 1 H-NMR spectrum of methanol- d 4 showed the presence of seven phenyl group protons [ δ H = 7.33 (1H, dd ), 7.33 (1H, dd ), 7.71 (1H, d ), 6.82 (1H, dd ), 6.82 (1H, dd ), 6.52 (1H, dd ), and 6.32 ppm (1H, d ),], two alkane protons [5.12 (1H, d ) and 4.22 ppm (1H, d )], and one methoxy proton [3.29 ppm (3H, s )]. 13 C-NMR spectrum revealed the presence of sixteen carbon signals, including twelve phenyl carbons [ δ C = 166.9, 164.8, 159.2, 130.1, 130.1, 130.1, 129.2, 116.2, 116.2, 114.0, 112.1, and 103.6 ppm], two alkane carbons [84.1 and 83.3 ppm], one carbonyl carbon [193.4 ppm], and one methoxy carbon [60.6 ppm]. A similar structure of A ring and carbonyl carbon at C-4 as 7 was confirmed by the AMX system of protons H-5 (doublet, 7.71 ppm, J = 9.6), H-6 (doublet, 6.52 ppm, J = 1.8, 9.6), H-8 (doublet, 6.32 ppm, J = 2.4), and the COSY correlation of H-5/C-6. The two double doublets with an integrated value of 2, H-2’ and H-6’ (double doublet, 7.33 ppm, J = 1.8, 7.2 Hz), and H-3’ and H-5’ (double doublet, 6.82 ppm, J = 1.8, 6.6 Hz) indicated that the B ring was a disubstituted benzene. In addition, the phenol moiety was confirmed by the downfield shift of C-4’ (159.2 ppm) and a series of HMBC correlation of H-2/C-6’, H-2’/C-2, and H-3’/C-4’. The position of the methoxy group was determined based on the HMBC correlation of H-3/OCH 3 . Thus, the planar structure of 6 was determined to be 3-methoxyliquiritigenin. The relative configuration of 6 was determined based on the coupling constants of H-2 (doublet, 5.12 ppm, J = 11.4 Hz) and H-3 (doublet, 4.22 ppm, J = 10.2 Hz) as 2,3- trans . The absolute configuration of 6 was determined from its ECD spectrum (Fig. S5-7). The experimental ECD spectrum of 6 showed a positive Cotton effect at approximately 331, 236, and 214 nm and a negative Cotton effect at approximately 302 nm. This result is in good agreement with the calculated ECD spectra of (2 S , 3 R )- 6 . Thus, the absolute configuration of 6 was determined to be 3 S -methoxy-2 S -liquiritigenin. Compound 5 was isolated as colorless crystals. The MALDI-TOF MS analysis in the positive mode generated an [M + Na] + ion at m/z 325.0688 (calculated for C 16 H 14 NaO 6, m/z 325.0688), indicating the molecular formula C 16 H 14 O 6 (Fig.S4- 1 ). The structure was elucidated based on the analysis of the NMR spectra (Fig.S4- 2 to S4-6). The comparison of the spectroscopic data of 5 and 6 differed in terms of the coupling system in the B ring, H-2’ (doublet, 7.01 ppm, J = 2.4 Hz), H-5’ (doublet, 6.75 ppm, J = 7.8 Hz), and H-6’ (double doublet, 6.82 ppm, J = 1.8, 7.8 Hz). The catechol moiety was confirmed as the B ring by two downfield shifted carbon C-3’ (146.6 ppm) and C-4’ (146.1 ppm) and a series of HMBC correlation of H-2/C-2’, C-6’, H-5’/C-3’, and H-6’/C-4’. Thus, the planar structure of 5 was determined to be 3 R -methoxybutin. The relative configuration of 5 was determined based on the coupling constants of H-2 (doublet, 5.31 ppm, J = 1.8 Hz) and H-3 (doublet, 3.73 ppm, J = 1.8 Hz) as 2,3- cis . The absolute configuration of 5 was determined from its ECD spectrum (Fig. S4-7). The experimental ECD spectrum of 5 showed positive Cotton effects at approximately 324, 269, 233, and 217 nm, and a negative Cotton effect at approximately 293 nm. This result is in good agreement with the calculated ECD spectrum of (2 S , 3 R )- 5 . Thus, the absolute configuration of 6 was determined to be 3 R -methoxy-(+)-butin. 5.2.2 Structure determination of dimer Compound 9 was isolated as colorless crystals. The MALDI-TOF MS analysis in the positive mode generated an [M + Na] + ion at m/z 609.1369 (calculated for C 32 H 26 NaO 11, m/z 609.1373), indicating the molecular formula C 32 H 26 NaO 11 (Fig.S7- 1 ). The structure was elucidated based on the analysis of the NMR spectra (Fig.S7- 2 to S7-6). The 1 H-NMR spectrum showed the presence of nine phenyl group protons [ δ H = 7.17 (1H, d ), 7.10 (1H, d ), 6.95 (1H, d ), 6.94 (1H, d ), 6.88 (1H, d ), 6.86 (1H, s ), 6.56 (1H, d ), 6.53 (1H, dd ), and 6.52 ppm (1H, s )] and ten alkane protons [5.02 (1H, d ), 5.00 (1H, d ), 4.96 (1H, d ), 4.92 (1H, d ), 4.87 (1H, d ), 4.84 (1H, d ), 4.80 (1H, d ), 4.71 (1H, br d ), 4.18 (1H, dd ), and 3.55 ppm (1H, dd )]. The 13 C-NMR spectrum showed thirty two resonances, including twenty four phenyl carbons [ δ C = 158.2, 157.3, 156.5, 154.5, 144.3, 144.3, 141.0, 141.0, 132.9, 132.1, 125.9, 125.9, 123.8, 123.3, 122.7, 118.2, 117.8, 117.6, 115.0, 114.9, 114.8, 110.3, 104.3, and 103.5 ppm] and eight alkane carbons [78.6, 76.4, 72.6, 69.8, 67.6, 65.7, 65.4, and 39.6 ppm]. For protonated carbon, the correspondences between the protons and the carbons were determined based on the HMQC spectrum. The COSY spectrum exhibited a coupled proton systems attributed to H-5 (doublet, 6.88 ppm, J = 8.4 Hz) and H-6 (double doublet, 6.53 ppm, J = 2.5, 8.2 Hz), H-5’ (doublet, 6.83 ppm, J = 8.4 Hz) and H-6’ (doublet, 6.99 ppm, J = 8.4 Hz), and H-5’’’’ (doublet, 6.95 ppm, J = 8.4 Hz) and H-6’’’’ (doublet, 7.10 ppm, J = 8.8 Hz), and two of three coupling protons of H-2 (doublet, 5.00 ppm, J = 9.9 Hz), H-3 (double doublet, 4.18 ppm, J = 5.9, 9.8 Hz), H-4 (doublet, 4.84 ppm, J = 5.9 Hz), and H-2’’’ (doublet, 4.87 ppm, J = 10.0 Hz), H-3’’’ (double doublet, 3.55 ppm, J = 8.6, 9.9 Hz), and H-4’’’ (doublet, 4.72 ppm, J = 8.4 Hz). These data indicate that 9 is a flavonoid dimer. One of the mopanol units was confirmed by a series of HMBC of H-3’’’’/C-1’’’’’, H-5’’’/C-4’’’, H-6’’’’/C-2’’’, and H-1’’’’’/C-1’’’’ with a difference of absence of H-6’’’. Another mopanol unit was determined by the HMBC correlations of H-3/C-1’, H-4/C-4a, H-1’’’/C-3, C-2’, and C-3’ without a hydroxy group at C-4. The binding mode of these two molecules of mopanol was determined by the HMBC correlations of H-4/C-5’’’, C-6’’’, and C-7’’’ to be C-4 (39.6 ppm) to C-6’’’ (110.3 ppm). Thus, the planar structure of 9 was determined to be mopanol-(4, 6)-mopanol. The relative configuration of each mopanol units in 9 was determined based on the coupling constants. The relative configuration of one of the mopanol units (composed of C-1 to C-1’’) was determined to be 2,3- trans -3,4- cis based on the coupling constants of H-2 (doublet, 5.00 ppm, J = 9.9 Hz), H-3 (double doublet, 4.18 ppm, J = 5.9, 9.8 Hz), and H-4 (doublet, 4.84 ppm, J = 5.9 Hz). Another mopanol moiety (composed of C-1’’’ to C-1’’’’’) was determined to be 2,3- trans -3,4- trans based on the coupling constants of H-2’’’ (doublet, 4.87 ppm, J = 10.0 Hz), H-3’’’ (double doublet, 3.55 ppm, J = 8.6, 9.9 Hz), and H-4’’’ (doublet, 4.72 ppm, J = 8.4 Hz). The absolute configuration of 9 was determined from its ECD spectrum (Fig. S7-7). The experimental ECD spectrum of 9 shows a positive Cotton effect at approximately 217 nm and a negative cotton effect at approximately 206 nm. This result is in good agreement with the calculated ECD spectrum of (2 R , 3 S , 4 S , 2’’’ R , 3’’’ S , 4’’’ R )- 9 . Thus, the absolute configuration of 9 was determined to be (+)-mopanol B-(4β→6’’’)-(+)-mopanol. A dimer composed of peltogynoids was isolated and structurally determined for the first time in this study. 5.3 Effect of light exposure to isolated compounds Before being exposed to room light in the air, 5 , 7 , 9 , 10 , and 11 were colorless, and 1 , 3 , 4 , and 6 ranged from pale yellow to yellow. After these methanol solutions were exposed to room light and air for 24h, only (+)-peltogynol ( 1 ) and (+)-mopanol ( 4 ) showed purple discoloration (Fig. 1 b). The color changes of all flavonoids were confirmed using CIE LAB parameters (Table S1 ). Immediately after isolation, all compounds showed positive a* and b* values, hile only the b* values of (+)-peltogynol ( 1 ) and (+)-mopanol (4) changed to negative values (-0.7 and − 1.8, respectively) after light exposure. The h * values (Δ h * 0h→24h ) of (+)-peltogynol ( 1 ) and (+)-mopanol ( 4 ) changed to -54.9 and − 75.8, respectively, while those of other compounds remained between − 0.7 and 5.6. These results suggested that (+)-peltogynol ( 1 ) and (+)-mopanol ( 4 ) are precursors to pigment compounds among isolated compounds in this study. These compounds have a hetero-six-membered ring (D ring) and a hydroxyl group at C-4 in R -configuration. In addition, C-2, C-3, and C-4 were chiral carbons with 2 R , 3 S , 4 R configuration. These structural characteristics are similar to the structure of leucoanthocyanidins. Leucoanthocyanidins are easily oxidized by organic acids or air and undergo structural changes to anthocyanidins via the elimination of the 4-hydroxyl group (Clark-Lewis and Williams 1967 ). Scince (+)-peltogynol ( 1 ) and (+)-mopanol ( 4 ) both have a hydroxyl group at the 4-hydroxyl group, it is possible that the similar structural change could occur to generate anthocyanidins. The newly isolated compound 9 was thought to be a proanthocyanidin generated by an intermediate that formed a bond at C-4 with (+)-mopanol at C-6, providing evidence for this mechanism. Conclusion In this study, five new peltogynoids and two new flavanones were isolated with four known compounds from the heartwood of P. mexicana . This study aimed to identify compounds related to heartwood discoloration as precursors to pigment compounds. Among the isolated compounds, (+)-peltogynol ( 1 ) and (+)-mopanol ( 4 ) contributed to the discoloration to reddish and blueish purple, respectively, upon exposure to room light in the air. In terms of their CIE LAB parameters, the b* values of these two compounds decreased and their a* values increased significantly. These results showed that discoloration was accelerated by exposure to room light in the air for both the methanol extract and the isolated compounds. These two compounds possess a sub-structure similar to that of flavan-3,4- trans -diol. These structural features provide insights into the mechanism of discoloration in P. Mexicana , and the heartwood contains anthocyanin-like pigment compounds. However, the isolation of dimer compound 9 is believed to contribute greatly to the elucidation of the structure of the pigment compound. 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Schlegel, et al (2016) Gaussian 16W, Revision C.01 Paulina G-M, Cinthya GG-Z, Leticia G-S, Cynthia O-P (2019) Purple pigment from Peltogyne mexicana heartwood as a potential colorant for food. J Food Sci Technol 56:3225–3238 S. E. Drewes, D. G. Roux (1967) Isolation of mopanin from Colophospermum mopane and interrelation of flavonoid components of Peltogyne spp. Journal of the Chemical Society C: Organic 1407–1410. https://doi.org/10.1039/J39670001407 S. E. Drewes, D. G. Roux (1966) Stereochemistry and biogenesis of mopanols and peltogynols and associated flavanoids from Colophospermum mopane. Journal of the Chemical Society C: Organic 1644–1653. https://doi.org/10.1039/J39660001644 Supap N, Anuchita M, Sirirat D (2012) Application of Functional Colorant Prepared from Black Rice Bran in Yogurt. APCBEE Procedia 2:62–67. https://doi.org/10.1016/J.APCBEE.2012.06.012 T. Bruhn, A. Schaumlöffel, Y. Hemberger, G. Pescitelli (2017) SpecDis Version 1.71 W. R. Chan, W. G. C. Forsyth, C. H. Hassall (1958) The constitution of the leucoanthocyanidin, peltogynol. Journal of the Chemical Society (Resumed) 3174–3179. https://doi.org/10.1039/JR9580003174 Tables Table 1 1 H and 13 C chemical shifts and 2D NMR correlation of 3 in acetone- d 6 ( δ in ppm, J in Hz) Position δ H (ppm) ( J in Hz) δ C (ppm) COSY HMBC 2 4.80 d 1H J = 11.4 72.6 3 1’, 2’ 3 3.69 dd 1H J = 7.8, 9.6 77.5 2, 4 1”, 2, 4 4 4.55 d 1H J = 8.4 78.8 3 -OCH 3 , 3, 4a, 8a 4a 115.5 5 7.23 d 1H J = 7.8 130.4 6 4, 7, 8a 6 6.49 dd 1H J = 3.0, 8.4 110.0 5 4a, 7, 8 7 158.9 8 6.34 d 1H J = 3.0 103.3 4a, 6, 7, 8a 8a 156.4 1' 125.6 2' 123.1 3' 141.0 4' 144.3 5' 6.84 d 1H J =8.4 114.6 6’ 1’, 3’, 4’ 6' 6.99 d 1H J =8.4 117.8 5’ 2, 5’, 2’, 4’ 1” 4.79 d 1H J = 4.8 65.2 1” 3, 1’, 2’ 4.92 d 1H J = 4.8 1” 3, 1’, 2’, 3’ -OCH 3 3.60 s 3H 58.3 4 Table 2 1 H and 13 C chemical shifts and 2D NMR correlation of 5 in methanol- d 4 ( δ in ppm, J in Hz) Position δ H (ppm) ( J in Hz) δ C (ppm) COSY HMBC 2 5.31 d 1H J = 1.8 82.4 3 1', 2', 6' 3 3.73 d 1H J = 1.8 82.4 2 -OCH3 4 190.6 4a 113.3 5 7.72 d 1H J = 9.0 130.3 6 4, 7 6 6.52 dd 1H J = 2.4, 9.0 112.1 5 4a 7 166.8 8 6.37 d 1H J = 2.4 103.6 8a 8a 165.0 1' 129.0 2' 7.01 d 1H J = 2.4 115.9 2, 3', 6' 3' 146.6 4' 146.1 5' 6.75 d 1H J = 7.8 115.8 6' 1', 4' 6' 6.82 dd 1H J = 1.8, 7.8 120.0 5' 2, 4', 5' -OCH 3 3.31 s 3H 59.1 3 Table 3 1 H and 13 C chemical shifts and 2D NMR correlation of 6 in methanol- d 4 ( δ in ppm, J in Hz) Position δ H (ppm) ( J in Hz) δ C (ppm) COSY HMBC 2 5.12 d 1H J = 11.4 84.1 3 3, 6' 3 4.22 d 1H J = 10.2 83.3 2 2, -OCH 3 4 193.4 4a 114.0 5 7.71 d 1H J = 9.6 130.1 6 4, 7, 8a 6 6.52 dd 1H J = 1.8, 9.0 112.1 5 4a, 8 7 166.9 8 6.32 d 1H J = 2.4 103.6 6, 8a 8a 164.8 1' 129.2 2' 7.33 dd 1H J = 1.8, 7.2 130.1 3' 2, 4' 3' 6.82 dd 1H J = 1.8, 6.6 116.2 2' 1', 4', 5' 4' 159.2 5' 6.82 dd 1H J = 1.8, 6.6 116.2 6' 3', 4' 6' 7.33 dd 1H J = 1.8, 7.2 130.1 5' 2, 4' -OCH 3 3.29 s 3H 60.6 3 Table 4 1 H and 13 C chemical shifts and 2D NMR correlation of 7 in methanol- d 4 ( δ in ppm, J in Hz) Position δ H (ppm) ( J in Hz) δ C (ppm) COSY HMBC 2 4.56 d 1H J = 11.4 76.4 3 3, 4, 1' 3 4.37 d 1H J = 11.4 77.8 2 4, 1', 1” 4 191.3 4a 114.3 5 7.75 d 1H J = 9.0 130.2 6 4, 7, 8a 6 6.56 dd 1H J = 2.4, 9.0 112.3 5 4a, 8 7 166.8 8 6.46 d 1H J = 2.4 103.9 6, 7, 8a 8a 164.5 1' 124.1 2' 126.8 3' 6.50 s 1H 111.3 1', 4', 1” 4' 146.0 5' 147.1 6' 7.06 s 1H 113.1 2, 2', 5' 1” 4.80 d 2H 69.4 3, 1', 2', 3' J = 14.4 Table 5 is available in the Supplementary Files section. Table 6 1 H and 13 C chemical shifts and 2D NMR correlation of 10 in acetone- d 6 ( δ in ppm, J in Hz) Position δ H (ppm) ( J in Hz) δ C (ppm) COSY HMBC 2 4.50 s 1H 68.3 3, 1', 6' 3 105.7 4 195.3 4a 113.2 5 7.48 d 1H J = 7.0 127.4 6 4, 7, 8a 6 6.56 dd 1H J = 2.0 , 7.0 113.2 5 4a, 8 7 174.5 8 6.36 d 1H J = 2.0 99.4 7, 4a, 8a 8a 169.6 1' 125.9 2' 125.7 3' 6.57 s 1H 111.4 2', 4', 1” 4' 145.9 5' 146.8 6' 6.82 s 1H 115.7 1', 2', 5' 1” 4.87 d 1H J = 14.0 66.0 3, 2' 4.87 d 1H J = 14.0 Table 7 1 H and 13 C chemical shifts and 2D NMR correlation of 11 in acetone- d 6 ( δ in ppm, J in Hz) Position δ H (ppm) ( J in Hz) δ C (ppm) COSY HMBC 2 4.78 d 1H J = 9.6 72.7 3 3, 1’, 2’, 3’ 3 3.70 dd 1H J = 8.4, 9.6 78.1 2, 4 1’’, 2, 4 4 4.54 dd 1H J = 8.4 78.8 3 -OCH 3 , 3, 4a, 8a 4a 115.5 5 7.22 dd 1H J = 8.4 130.4 6 4, 7, 8a 6 6.49 dd 1H J = 2.4, 8.4 110.0 5 4a 7 158.9 8 6.36 d 1H J = 2.4 103.3 6, 8a 8a 156.3 1' 127.2 2' 124.6 3' 6.57 s 1H 111.0 2’, 5’ 4' 145.0 5' 146.0 6' 7.08 s 1H 113.5 2, 1’, 4’ 1'' 4.79 d 1H J = 10.2 68.1 1’’ 2’ 4.92 d 1H J = 10.2 -OCH 3 3.57 s 1H 58.3 4 Additional Declarations No competing interests reported. Supplementary Files Supportinginformation1.docx Table5.docx Cite Share Download PDF Status: Published Journal Publication published 15 Nov, 2024 Read the published version in Wood Science and Technology → Version 1 posted Editorial decision: Revision requested 06 Oct, 2024 Reviews received at journal 28 Aug, 2024 Reviewers agreed at journal 11 Aug, 2024 Reviewers agreed at journal 08 Aug, 2024 Reviews received at journal 06 Aug, 2024 Reviewers agreed at journal 30 Jul, 2024 Reviewers invited by journal 30 Jul, 2024 Editor assigned by journal 23 Jul, 2024 Submission checks completed at journal 19 Jul, 2024 First submitted to journal 17 Jul, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4759481","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":338713006,"identity":"9f937f0a-b1ac-4950-a925-7375fe3517b5","order_by":0,"name":"Yusuke Taga","email":"","orcid":"","institution":"Gifu University","correspondingAuthor":false,"prefix":"","firstName":"Yusuke","middleName":"","lastName":"Taga","suffix":""},{"id":338713007,"identity":"bf1fda47-d918-402f-b409-366e577d81ec","order_by":1,"name":"Kosei Yamauchi","email":"data:image/png;base64,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","orcid":"","institution":"Gifu University","correspondingAuthor":true,"prefix":"","firstName":"Kosei","middleName":"","lastName":"Yamauchi","suffix":""},{"id":338713008,"identity":"9bf583ee-33fa-4ae3-9d74-f69dc0520da5","order_by":2,"name":"Tohru Mitsunaga","email":"","orcid":"","institution":"Gifu University","correspondingAuthor":false,"prefix":"","firstName":"Tohru","middleName":"","lastName":"Mitsunaga","suffix":""}],"badges":[],"createdAt":"2024-07-18 02:54:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4759481/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4759481/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00226-024-01617-3","type":"published","date":"2024-11-15T15:58:15+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":62358836,"identity":"6e5da8f4-ba22-4df9-ad97-759f8284ae85","added_by":"auto","created_at":"2024-08-13 09:45:57","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":64357,"visible":true,"origin":"","legend":"\u003cp\u003eDiscoloration of extract, soluble parts, and isolated compounds by light and air exposure (a) Discoloration of methanol extract and each soluble part (ME: methanol extract, HS: Hexane soluble part, ES: ether soluble part, EAS: ethyl acetate soluble part, MS: methanol soluble part) (b) Discoloration of (+)-peltogynol (\u003cstrong\u003e1\u003c/strong\u003e) and (+)-mopanol (\u003cstrong\u003e4\u003c/strong\u003e)\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4759481/v1/8684596b5b248fbd78c138ba.jpg"},{"id":62358833,"identity":"139a4394-e04e-4287-b85e-8841c0ff98cb","added_by":"auto","created_at":"2024-08-13 09:45:57","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":59334,"visible":true,"origin":"","legend":"\u003cp\u003eisolated compounds from \u003cem\u003eP. mexicana\u003c/em\u003e heartwood\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4759481/v1/2c89cd88101f414d24d8cc92.jpg"},{"id":69285110,"identity":"eec63bcf-2bad-4f6e-bf57-cb1638e7cc24","added_by":"auto","created_at":"2024-11-18 19:23:55","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1264131,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4759481/v1/83cb556b-c656-4a53-94bc-a0e89aac8280.pdf"},{"id":62358837,"identity":"c0908420-3dc7-4e34-990a-e1aceeafcc52","added_by":"auto","created_at":"2024-08-13 09:45:57","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":8631578,"visible":true,"origin":"","legend":"","description":"","filename":"Supportinginformation1.docx","url":"https://assets-eu.researchsquare.com/files/rs-4759481/v1/2cbe3c23a27d9a9d18fb2bcb.docx"},{"id":62359444,"identity":"072b8734-9c62-4b6a-89cf-0080f283c9c0","added_by":"auto","created_at":"2024-08-13 09:53:57","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":21555,"visible":true,"origin":"","legend":"","description":"","filename":"Table5.docx","url":"https://assets-eu.researchsquare.com/files/rs-4759481/v1/0f79997c2ad6ac0c1aa88763.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Peltogynoids contributing to discoloration in Peltogyne mexicana heartwood","fulltext":[{"header":"Introduction","content":"\u003cp\u003e \u003cem\u003ePeltogyne mexicana\u003c/em\u003e is native to neotropical regions, including Guiana and Brazil, and grows a height of 30\u0026ndash;40 m (Janet et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). The heartwood of \u003cem\u003ePeltogyne\u003c/em\u003e trees is well known to metabolize characteristic flavonoid, peltogynoids (S. E. Drewes and D. G. Roux 1967). This group of flavonoids has a hetero-six-membered ring (D ring) that connects the B and C rings of flavan-3-ol \u003cem\u003evia\u003c/em\u003e an oxyethylene bridge (Mathew et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). In the first isolation report on peltogynoids, (+)-peltogynol was isolated from \u003cem\u003eP. porphyrocardia Griseb\u003c/em\u003e. ex \u003cem\u003eBenth\u003c/em\u003e, and its absolute configuration was determined to be 2\u003cem\u003eR\u003c/em\u003e, 3\u003cem\u003eS\u003c/em\u003e, 4\u003cem\u003eR\u003c/em\u003e (G. M. Robinson and R. Robinson \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e1935\u003c/span\u003e; Hassall and Weatherston \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e1965\u003c/span\u003e). Currently, various peltogynoids have been isolated from various species, including \u003cem\u003ePeltogyne\u003c/em\u003e, \u003cem\u003eColophospermum\u003c/em\u003e, and \u003cem\u003eCassine\u003c/em\u003e (W. R. Chan et al. \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e1958\u003c/span\u003e; E. Drewes et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e1991\u003c/span\u003e; Daneel et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2003\u003c/span\u003e). Peltogynoid shows variety of pharmacological activities, such as anti-inflammatory activity of myrtinol E isolated from \u003cem\u003eBackhousia myrtifolia\u003c/em\u003e (Mathew et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2023\u003c/span\u003e), cytotoxicity against cancer cells of bougainvinone G isolated from \u003cem\u003eBougainvillea spectabilis\u003c/em\u003e (Do et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), and kinase inhibitory activity of acanilol B isolated from \u003cem\u003eAcacia nilotica\u003c/em\u003e (Ahmadu et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2010\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cem\u003eP. mexicana\u003c/em\u003e heartwood, which contains peltogynoids, is well known for its purple discoloration, hence, it is commonly referred to \u0026ldquo;Purple heart\u0026rdquo;. The heartwood gradually turns bright purple after its surface is exposed to air and sunlight, while it shows pale yellow immediately after harvesting or injury (Paulina et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Janet et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Because of this unique purple color and the high durability as wood material (Marcos et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), P. \u003cem\u003emexicana\u003c/em\u003e heartwood has a high market value and is used as high-grade wood material in a wide range of industries. The phenomenon in which the color of heartwood changes after being cut down has been reported for various species used for high-end desks and furniture, including \u003cem\u003eCaesaplinia sappan\u003c/em\u003e and \u003cem\u003eMillettia pendula.\u003c/em\u003e Regarding the heartwood of \u003cem\u003eCaesaplinia sappan\u003c/em\u003e, called sappan wood, brazilin is autoxidized to brazilein and appears red in color (Kim et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e1997\u003c/span\u003e; De Oliveira et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). The heartwood of \u003cem\u003eMillettia pendula\u003c/em\u003e turns dark purple after being harvested. This heartwood contains 7,3',4'-trihydroxy-6'-methoxyisoflav-3-ene, which forms quinone methide when oxidized, and turns dark purple in color (Mitsunaga et al. \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e1987a\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003eb\u003c/span\u003e). As shown in these examples, discoloration in heartwood often results from oxidative reactions (Laver and Arvey \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e1996\u003c/span\u003e; Chang et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2000\u003c/span\u003e). In \u003cem\u003eP. mexicana\u003c/em\u003e, the production of red compounds was observed when peltogynoids were heated under acidic conditions (G. M. Robinson and R. Robinson \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e1935\u003c/span\u003e; Brandt and Roux \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e1979\u003c/span\u003e). In another report, peltomexicanin, in which the B ring exhibits a quinone methide form, was isolated as a heartwood pigment compound (Guti\u0026eacute;rrez-Mac\u0026iacute;as et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). However, no research has focused on the precursors to the pigment compounds involved in this discoloration. In this study, isolation of various peltogynoids and other flavonoids from \u003cem\u003eP. mexicana\u003c/em\u003e heartwood was conducted to identify compounds responsible for heartwood discoloration as precursors.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003e\u003cstrong\u003e4.1\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eGeneral\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eExperimental procedures\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll of color measurement in this study was conducted using Color analyser TES-3250 (TES Electrical Electronic Corp. Taiwan). High-performance liquid chromatography (HPLC) analysis was performed using MD-2018 photodiode array detector (JASCO, Japan) equipped with a Sunniest C18 reversed phase column (5 mm × 250 mm length, ChromaNik Technologies Inc.) at flow rate of 1.0 mL/min, detection wavelength of 190-700 nm, and oven temperature of 35ºC. Regarding the mobile phase, 0.05% TFA aq. (A) and methanol (B) were used as mobile phases. The eluant was applied as a linear gradient elution for 50 min from 20% to 80% of solvent B. Preparative HPLC was conducted using a set of LC-6AD system (SHIMAZU, Japan) equipped with a Inertsil ODS-3 column (5 μm, 20 × 250 mm, GL Sciences, Japan) at flow rate of 9.0 mL/min.\u0026nbsp;Nuclear magnetic resonance (NMR) spectra were recorded on a JEOL JNM ECA-600 (JEOL, Japan), and Bruker Biospin AVANCE III 800 (bruker, USA). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) spectra were measured using a Shimadzu AXIMA resonance spectrometer equipped with a nitrogen laser (λ=337 nm). Electronic circular Dichroism (ECD) spectra were recorded on a J-820P spectrometer (JASCO, Japan) using 1 mm path precision cells.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.2\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eComputational details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor compounds with\u0026nbsp;chiral\u0026nbsp;centers, the absolute configuration was determined by\u0026nbsp;a computational\u0026nbsp;ECD calculation. All calculations were performed by the Gaussian16W program package(M.J. Frisch et al. 2016).\u003c/p\u003e\n\u003cp\u003eECD calculation was performed by the TD-SCF method at the WB97XD/6–31+G(d, p) level in\u0026nbsp;methanol\u0026nbsp;as solvent.\u0026nbsp;The final ECD spectra were obtained according to the Boltzmann-calculated contribution of each conformer by SpecDis(T. Bruhn et al. 2017). The calculated experimental data were compared with the ECD spectra.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.3\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003ePlant materials\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;and extraction\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWood materials of\u0026nbsp;\u003cem\u003ePeltogyne mexicana\u003c/em\u003e heartwood was obtained from a timber dealer (Yamagataya Industry Co., Ltd., Japan).\u0026nbsp;Heart wood (600 g) was crushed to powder states and extracted with 2 L of methanol, then dried methanol extract was partitioned\u0026nbsp;successively\u0026nbsp;twice with\u0026nbsp;\u003cem\u003en\u003c/em\u003e-hexane, diethyl ether, ethyl acetate, and methanol using 2 L each. Each soluble part was evaporated\u0026nbsp;and all of extract procedure was conducted under dark condition.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.\u003c/strong\u003e\u003cstrong\u003e4CIE LAB parameter\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe color of methanol extract, each soluble part, and isolated flavonoids\u0026nbsp;were evaluated using CIE LAB parameters\u0026nbsp;(\u003cem\u003ea*\u003c/em\u003e,\u0026nbsp;\u003cem\u003eb*\u003c/em\u003e,\u0026nbsp;\u003cem\u003eL*\u003c/em\u003e). Besides,\u0026nbsp;the values of\u0026nbsp;\u003cem\u003eh*\u003c/em\u003e,\u0026nbsp;\u0026nbsp;,\u0026nbsp;\u0026nbsp;,\u0026nbsp;\u0026nbsp;,,\u0026nbsp;and\u0026nbsp;\u0026nbsp;were calculated\u0026nbsp;from CIE LAB parameters\u0026nbsp;(Supap et al. 2012; Jung and Sato 2013). Discolorations in this study were evaluated by a changing these parameters.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.\u003c/strong\u003e\u003cstrong\u003e5\u003c/strong\u003e\u003cstrong\u003eLight exposure behavior of extract and soluble parts\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA 5 mg of methanol extract or each soluble part was dissolved with 1.5 ml of methanol and removed into a small vial. The\u0026nbsp;degree of discoloration\u0026nbsp;was evaluated by exposure the vials\u0026nbsp;to a room\u0026nbsp;light (approximately 470 lx) in the air at room temperature\u0026nbsp;for 24 hours. Refer to measuring\u0026nbsp;the color, filter paper chip cut into a circle shape\u0026nbsp;with a diameter of 1.5 cm, then impregnated in methanol extract and each soluble\u0026nbsp;parts part before and after exposure, and the values of\u0026nbsp;\u003cem\u003ea*\u003c/em\u003e,\u0026nbsp;\u003cem\u003eb*\u003c/em\u003e, and\u0026nbsp;\u003cem\u003eL*\u003c/em\u003e were measured using a color\u0026nbsp;anolyser.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.\u003c/strong\u003e\u003cstrong\u003e6\u003c/strong\u003e\u003cstrong\u003e Compounds isolation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll separation\u0026nbsp;procedure procedures were monitored by TLC and HPLC profiles. The part of diethyl ether\u0026nbsp;soluble part\u0026nbsp;(10.0 g) was\u0026nbsp;fractionated on an\u0026nbsp;open silica gel column chromatography (80 mmφ×600 mm) and eluted with ethyl acetate :\u0026nbsp;\u003cem\u003en\u003c/em\u003e-hexane (4 : 6, v/v) to obtain four subfractions (EFr.1-4).\u0026nbsp;Subfraction EFr.3 (2 g) was\u0026nbsp;further fractionated on an\u0026nbsp;open silica gel column chromatography (70 mmφ×300 mm) and eluted with methanol : chloroform (3 : 7, v/v) to obtain five subfractions (EFr.3-1 – 3-5). EFr.3-5 (147.3 mg) was subjected to open ODS-silica gel column chromatography (40 mmφ×150 mm) and eluted with 70 % methanol aq. to yield\u0026nbsp;\u003cstrong\u003e1\u003c/strong\u003e (19.1 mg).\u0026nbsp;\u003cstrong\u003e4\u0026nbsp;\u003c/strong\u003e(15.6 mg), and\u0026nbsp;\u003cstrong\u003e10\u003c/strong\u003e (4.0 mg)\u0026nbsp;were purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min]\u0026nbsp;from EFr.3-4 (47.0 mg). Subfraction EFr.2 (197.1 mg) was\u0026nbsp;further fractionated on an\u0026nbsp;open silica gel column chromatography (60 mmφ×300 mm) and eluted with methanol : chloroform (2 : 8, v/v) to obtain four subfractions (EFr.2-1 – 2-4),\u0026nbsp;then \u003cstrong\u003e2\u0026nbsp;\u003c/strong\u003e(3.5 mg)\u0026nbsp;was purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min] from EFr.2-1 (22.5 mg). EFr.2-2 (129.4 mg) was subjected to open silica gel column chromatography (30 mmφ×320 mm) and eluted with methanol : chloroform (1 : 9, v/v) to obtain four subfractions (EFr.2-2-1 – 2-2-4). then\u0026nbsp;\u003cstrong\u003e3\u0026nbsp;\u003c/strong\u003e(12.5 mg),\u0026nbsp;\u003cstrong\u003e5\u0026nbsp;\u003c/strong\u003e(2.7 mg),\u0026nbsp;and\u0026nbsp;\u003cstrong\u003e6\u0026nbsp;\u003c/strong\u003e(3.2 mg)\u0026nbsp;were purified by\u0026nbsp;preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min]\u0026nbsp;from EFr.2-2-2 (53.2 mg). The part of ethyl acetate\u0026nbsp;soluble part\u0026nbsp;(1.0 g) was\u0026nbsp;fractionated on an\u0026nbsp;open silica gel column chromatography (80 mmφ×600 mm) and eluted with ethyl acetate :\u0026nbsp;\u003cem\u003en\u003c/em\u003e-hexane (2 : 8, v/v) to obtain three subfractions (AFr.1-3).\u0026nbsp;Subfraction AFr.2 (392.9 mg) was further fractionated on an\u0026nbsp;open silica gel column chromatography (35 mmφ×350 mm) and eluted with ethyl acetate :\u0026nbsp;\u003cem\u003en\u003c/em\u003e-chloroform (8:2, v/v) to obtain 3 subfractions (AFr.2-1 – 2-3), then\u0026nbsp;\u003cstrong\u003e7\u0026nbsp;\u003c/strong\u003e(8.7 mg) was\u0026nbsp;purified by\u0026nbsp;preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min]\u0026nbsp;from EFr.2-3 (23.0 mg).\u0026nbsp;\u003cstrong\u003e8\u0026nbsp;\u003c/strong\u003e(2.6 mg) was\u0026nbsp;purified by\u0026nbsp;preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min]\u0026nbsp;from EFr.2-1 (8.1 mg). Subfraction AFr.3 (80.7 mg) was\u0026nbsp;further fractionated on an open silica gel column chromatography (40 mmφ×300 mm) and eluted with methanol :\u0026nbsp;\u003cem\u003en\u003c/em\u003e-chloroform (3 : 7, v/v) to obtain 8 subfractions (AFr.3-1 – 3-8), then\u0026nbsp;\u003cstrong\u003e9\u0026nbsp;\u003c/strong\u003e(4.4 mg)\u0026nbsp;was purified by\u0026nbsp;preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min]\u0026nbsp;from EFr.3-8 (23.0 mg). The part of ethyl acetate\u0026nbsp;soluble part\u0026nbsp;(3.3 g) was\u0026nbsp;fractionated on an\u0026nbsp;open LH-20 gel column chromatography (50 mmφ×300 mm) and eluted with methanol : chloroform (5 : 5, v/v) to obtain four subfractions (LHFr.1-4). Subfraction LHFr.3 (150.6 mg) was\u0026nbsp;further fractionated on an\u0026nbsp;open ODS-silica gel column chromatography (25 mmφ×210 mm) and 60 % methanol aq. to obtain four subfractions (LHFr.3-1 – 3-4), then\u0026nbsp;\u003cstrong\u003e11\u0026nbsp;\u003c/strong\u003e(6.6 mg)\u0026nbsp;was purified by preparative HPLC (wavelength at 210 nm) with a gradient elution of methanol : 0.05 % TFA aq. [20 : 80 (v/v) to 80 : 20 (v/v) for 50 min]\u0026nbsp;from LHFr.3-3 (20.4 mg).\u0026nbsp;Structures of isolated compounds were determined by\u0026nbsp;the NMR analysis and\u0026nbsp;the MALDI-TOF MS analysis. For steric compounds, ECD measurement was performed to determine their absolute configuration.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.\u003c/strong\u003e\u003cstrong\u003e7Spectroscopic data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e(+)-Peltogynol\u0026nbsp;(\u003cstrong\u003e1\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003ePale yellow crystal; ECD (\u003cem\u003ec\u003c/em\u003e 0.3 mM, methanol)\u0026nbsp;\u003cem\u003eλ\u003c/em\u003e\u003csub\u003emax\u003c/sub\u003e (Δ\u003cem\u003eε\u003c/em\u003e): 235.0 (+20.41), 289.0 (+4.50);\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003c/em\u003e\u003cem\u003e\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e) 3.52 (3-H, 1H,\u0026nbsp;\u003cem\u003edd\u003c/em\u003e), 4.74 (1”-H, 1H,\u0026nbsp;\u003cem\u003ed\u003c/em\u003e) 4.76 (4-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 4.77 (2-H, 1H,\u0026nbsp;\u003cem\u003ed\u003c/em\u003e), 6.35 (8-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 6.49 (6-H, 1H,\u0026nbsp;\u003cem\u003edd\u003c/em\u003e), 6.56 (5’-H, 1H,\u0026nbsp;\u003cem\u003es\u003c/em\u003e), 7.09 (2’-H, 1H,\u0026nbsp;\u003cem\u003es\u003c/em\u003e), 7.35 (5-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e);\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003c/em\u003e\u003cem\u003e\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e) 68.3 (C-1”), 69.9 (C-4), 72.7 (C-2), 79.2 (C-3), 103.1 (C-8), 109.9 (C-6), 111.0 (C-5’), 113.4 (C-2’), 118.0 (C-4a), 124.9 (C-1’), 127.4 (C-6’), 130.1 (C-5), 145.0 (C-4’), 145.9 (C-3’), 155.9 (C-8a), 158.7 (C-7); MALDI-TOFMS\u0026nbsp;\u003cem\u003em/z\u003c/em\u003e 325.0692 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 325.0688, C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eNaO\u003csub\u003e6\u003c/sub\u003e)\u003c/p\u003e\n\u003cp\u003e2, 4-dihydroxybenzaldehyd\u0026nbsp;(\u003cstrong\u003e2\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003eWhite crystal;\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003c/em\u003e\u003cem\u003e\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 6.26 (3-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 6.43 (5-H, 1H,\u003cem\u003e\u0026nbsp;dd\u003c/em\u003e), 7.48 (6-H, 1H,\u0026nbsp;\u003cem\u003ed\u003c/em\u003e), 9.67 (7-H, 1H,\u0026nbsp;\u003cem\u003es\u003c/em\u003e);\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003c/em\u003e\u003cem\u003e\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 103.2 (C-3), 109.9 (C-5), 116.2 (C-1), 136.7 (C-6), 165.6 (C-2), 167.3 (C-4), 195.5 (C-7); MALDI-TOFMS\u0026nbsp;\u003cem\u003em/z\u003c/em\u003e 161.0216 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 161.0215, C\u003csub\u003e7\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003eNaO\u003csub\u003e3\u003c/sub\u003e)\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;4\u003cem\u003eR\u003c/em\u003e-methoxymopanol\u0026nbsp;(\u003cstrong\u003e3\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003ePale yellow crystal; ECD (\u003cem\u003ec\u003c/em\u003e 0.3 mM, methanol)\u0026nbsp;\u003cem\u003eλ\u003c/em\u003e\u003csub\u003emax\u003c/sub\u003e (Δ\u003cem\u003eε\u003c/em\u003e): 212.0 (+20.96), 227.0 (+5.79);\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 3.60 (-OCH\u003csub\u003e3\u003c/sub\u003e, 3H, \u003cem\u003es\u003c/em\u003e), 3.69 (3-H, 1H, \u003cem\u003edd\u003c/em\u003e), 4.55 (4-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.79 (1’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.80 (2-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.92 (1’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.34 (8-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 6.49 (6-H, 1H, \u003cem\u003edd\u003c/em\u003e), 6.84 (5’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.99 (6’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 7.23 (5-H, 1H, \u003cem\u003ed\u003c/em\u003e); \u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 58.3 (-OCH\u003csub\u003e3\u003c/sub\u003e), 65.2 (C-1’’), 65.2 (C-1’’), 72.6 (C-2), 77.5 (C-3), 78.8 (C-4), 103.3 (C-8), 110.0 (C-6), 114.6 (C-5’), 115.5 (C-4a), 117.8 (C-6’), 123.1 (C-2’), 125.6 (C-1’), 130.4 (C-5), 141.0 (C-3’), 144.3 (C-4’), 156.4 (C-8a), 158.9 (C-7); MALDI-TOFMS\u0026nbsp;\u003cem\u003em/z\u003c/em\u003e 339.0842 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 339.0845, C\u003csub\u003e17\u003c/sub\u003eH\u003csub\u003e16\u003c/sub\u003eNaO\u003csub\u003e6\u003c/sub\u003e). All NMR data were shown in Table\u0026nbsp;1.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e(+)-mopanol(\u003cstrong\u003e4\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003eYellow crystal; ECD (\u003cem\u003ec\u003c/em\u003e 0.3 mM, methanol)\u0026nbsp;\u003cem\u003eλ\u003c/em\u003e\u003csub\u003emax\u003c/sub\u003e (Δ\u003cem\u003eε\u003c/em\u003e): 211.0 (+15.31), 228.0 (+4.51);\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003c/em\u003e\u003cem\u003e\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 3.52 (3-H, 1H,\u0026nbsp;\u003cem\u003edd\u003c/em\u003e), 4.74 (1”-H, 1H,\u0026nbsp;\u003cem\u003ed\u003c/em\u003e), 4.78 (4-H, 1H,\u0026nbsp;\u003cem\u003ed\u003c/em\u003e), 4.79 (2-H, 1H,\u0026nbsp;\u003cem\u003ed\u003c/em\u003e), 5.07 (1”-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 6.36 (8-H, 1H,\u0026nbsp;\u003cem\u003ed\u003c/em\u003e), 6.49 (6-H, 1H,\u003cem\u003e\u0026nbsp;dd\u003c/em\u003e), 6.84 (5’-H, 1H,\u0026nbsp;\u003cem\u003ed\u003c/em\u003e), 6.99 (6’-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 7.36 (5-H, 1H,\u0026nbsp;\u003cem\u003ed\u003c/em\u003e);\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003c/em\u003e\u003cem\u003e\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 65.4 (C-1”), 65.4 (C-1”), 70.0 (C-4), 72.6 (C-2), 78.6 (C-3), 103.1 (C-8), 109.9 (C-6), 114.6 (C-5’), 117.8 (C-4a), 117.8 (C-6’), 123.2 (C-2’), 125.7 (C-1’), 130.0 (C-5), 141.0 (C-3’), 144.3 (C-4’), 155.8 (C-8a), 158.7 (C-7); MALDI-TOFMS\u0026nbsp;\u003cem\u003em/z\u003c/em\u003e 325.0689 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 325.0688, C\u003csub\u003e17\u003c/sub\u003eH\u003csub\u003e16\u003c/sub\u003eNaO\u003csub\u003e6\u003c/sub\u003e)\u003c/p\u003e\n\u003cp\u003e3\u003cem\u003eR\u003c/em\u003e-methoxy-(+)-butin\u0026nbsp;(\u003cstrong\u003e5\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003eColorless crystal;ECD (\u003cem\u003ec\u003c/em\u003e 0.3 mM, methanol)\u0026nbsp;\u003cem\u003eλ\u003c/em\u003e\u003csub\u003emax\u003c/sub\u003e (Δ\u003cem\u003eε\u003c/em\u003e): 324.4 (+3.15), 292.6 (-1.69), 268.8 (+1.19), 233.2 (+4.98), 217.2 (+6.92);\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003c/em\u003e\u003cem\u003e\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e)\u0026nbsp;3.31 (-OCH\u003csub\u003e3\u003c/sub\u003e, 3H, \u003cem\u003es\u003c/em\u003e), 3.73 (3-H, 1H, \u003cem\u003ed\u003c/em\u003e), 5.31 (2-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.37 (8-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.52 (6-H, 1H, \u003cem\u003edd\u003c/em\u003e), 6.75 (5’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.82 (6’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 7.01 (2’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 7.72 (5-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e);\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e)\u0026nbsp;59.1 (-OCH\u003csub\u003e3\u003c/sub\u003e), 82.4 (C-2), 82.4 (C-3), 103.6 (C-8), 112.1 (C-6), 113.3 (C-4a), 115.8 (C-5’), 115.9 (C-2’) 120.0 (C-6’) 129.0 (C-1’) 130.3 (C-5), 146.1 (C-4’), 146.6 (C-3’), 165.0 (C-8a), 166.8 (C-7), 190.6 (C-4); MALDI-TOFMS\u0026nbsp;\u003cem\u003em/z\u003c/em\u003e 325.0688 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 325.0688, C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eNaO\u003csub\u003e6\u003c/sub\u003e).\u0026nbsp;All NMR data were shown in Table\u0026nbsp;2.\u003c/p\u003e\n\u003cp\u003e3\u003cem\u003eS\u003c/em\u003e-methoxy-2\u003cem\u003eS\u003c/em\u003e-liquiritigenin\u0026nbsp;(\u003cstrong\u003e6\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003ePale yellow crystal; ECD (\u003cem\u003ec\u003c/em\u003e 0.3 mM, methanol)\u0026nbsp;\u003cem\u003eλ\u003c/em\u003e\u003csub\u003emax\u003c/sub\u003e (Δ\u003cem\u003eε\u003c/em\u003e): 331.4 (+1.31), 302.4 (-1.54), 236.0 (+2.13), 213.6 (+6.28);\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003c/em\u003e\u003cem\u003e\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e)\u0026nbsp;3.29 (-OCH\u003csub\u003e3\u003c/sub\u003e, 3H, s), 4.22 (3-H, 1H, d), 5.12 (2-H, 1H, d), 6.32 (8-H, 1H, d), 6.52 (6-H, 1H, dd), 6.82 (3'-H, 1H, dd), 6.82 (5'-H, 1H, dd), 7.33 (2'-H, 1H, dd), 7.33 (6'-H, 1H, dd), 7.71 (5-H, 1H, d);\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e)\u0026nbsp;60.6 (-OCH\u003csub\u003e3\u003c/sub\u003e), 83.3 (C-3), 84.1 (C-2), 103.6 (C-8), 112.1 (C-6), 114.0 (C-4a), 116.2 (C-3'), 116.2 (C-5'), 129.2 (C-1'), 130.1 (C-5), 130.1 (C-2'), 130.1 (C-6'), 159.2 (C-4'), 164.8 (C-8a), 166.9 (C-7), 193.4 (C-4); MALDI-TOFMS\u003cem\u003e\u0026nbsp;m/z\u003c/em\u003e 309.0739 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 307.0739, C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eNaO\u003csub\u003e5\u003c/sub\u003e). All NMR data were shown in Table\u0026nbsp;3.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e2\u003cem\u003eS\u003c/em\u003e, 3\u003cem\u003eS\u003c/em\u003e\u003cstrong\u003e-\u003c/strong\u003epeltogynone\u0026nbsp;(\u003cstrong\u003e7\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003eColorless crystal; ECD (\u003cem\u003ec\u003c/em\u003e 0.3 mM, methanol)\u0026nbsp;\u003cem\u003eλ\u003c/em\u003e\u003csub\u003emax\u003c/sub\u003e (Δ\u003cem\u003eε\u003c/em\u003e): 324.6 (+2.7), 292.8 (-1.5), 270.6 (+1.1), 233.0 (+4.8), 216.8 (+6.7);\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003c/em\u003e\u003cem\u003e\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e)\u0026nbsp;4.37 (3-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.56 (2-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.80 (1’’-H, 2H, \u003cem\u003ed\u003c/em\u003e), 6.46 (8-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.50 (3’-H, 1H, \u003cem\u003es\u003c/em\u003e), 6.56 (6-H, 1H, \u003cem\u003edd\u003c/em\u003e), 7.06 (6’-H, 1H, \u003cem\u003es\u003c/em\u003e), 7.75 (5-H, 1H, \u003cem\u003ed\u003c/em\u003e);\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e)\u0026nbsp;69.4 (C-1’’), 76.4 (C-2), 77.8 (C-3), 103.9 (C-8), 111.3 (C-3’), 112.3 (C-6), 113.1 (C-6’), \u0026nbsp;114.3 (C-4a), 124.1 (C-1’), 126.8 (C-2’), 130.2 (C-5), 146.0 (C-4’), 147.1 (C-5’), 164.5 (C-8a), 166.8 (C-7), 191.3 (C-4); MALDI-TOFMS\u003cem\u003e\u0026nbsp;m/z\u003c/em\u003e 323.0527 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 323.0531, C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eNaO\u003csub\u003e6\u003c/sub\u003e). All NMR data were shown in Table\u0026nbsp;4.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003esyringaldehyde\u0026nbsp;(\u003cstrong\u003e8\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003eWhite crystal;\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e) 3.98 (-OCH\u003csub\u003e3\u003c/sub\u003e, 6H,\u0026nbsp;\u003cem\u003es\u003c/em\u003e), 7.15 (2, 6-H, 2H,\u0026nbsp;\u003cem\u003es\u003c/em\u003e), 9.82 (7-H, 1H,\u0026nbsp;\u003cem\u003es\u003c/em\u003e);\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;methanol-\u003cem\u003ed\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e)56.5 (-OCH\u003csub\u003e3\u003c/sub\u003e), 106.7 (C-2), 106.7 (C-6), 147.3 (C-1), 164.1 (C-3), 164.1 (C-4), 164.1 (C-5), 190.7 (C-7); MALDI-TOFMS\u003cem\u003e\u0026nbsp;m/z\u003c/em\u003e 205.0471 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 205.0476, C\u003csub\u003e9\u003c/sub\u003eH\u003csub\u003e10\u003c/sub\u003eNaO\u003csub\u003e4\u003c/sub\u003e)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e(\u003c/strong\u003e\u003cstrong\u003e+)-\u003c/strong\u003emopanol B-(4β→6’’’)-(+)-molanol\u0026nbsp;(\u003cstrong\u003e9\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003eColorless crystal; ECD (\u003cem\u003ec\u003c/em\u003e 0.3 mM, methanol)\u0026nbsp;\u003cem\u003eλ\u003c/em\u003e\u003csub\u003emax\u003c/sub\u003e (Δ\u003cem\u003eε\u003c/em\u003e): 217.0 (+30.9), 206.4 (-42.3);\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 3.55 (3’’’-H, 1H, \u003cem\u003edd\u003c/em\u003e), 4.18 (3-H, 1H, \u003cem\u003edd\u003c/em\u003e), 4.72 (4’’’-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 4.80 (1’’’’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.84 (4-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.87 (2’’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.92 (1’’-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 4.96 (1’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 5.00 (2-H, 1H, \u003cem\u003ed\u003c/em\u003e), 5.02(1’’’’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.52 (8’’’-H, 1H, \u003cem\u003es\u003c/em\u003e), 6.53 (6-H, 1H, \u003cem\u003edd\u003c/em\u003e), 6.56 (8-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.86 (5’’’-H, 1H,\u003cem\u003e\u0026nbsp;s\u003c/em\u003e), 6.88 (5-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.95 (5’’’’-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 6.94 (5’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 7.10 (6’’’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 7.17 (6’-H, 1H, \u003cem\u003ed\u003c/em\u003e); \u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 39.6 (C-4), 65.4 (C-1’’’’’), 65.7 (C-1’’), 67.6 (C-2), 69.8 (C-4’’’), 72.6 (C-2’’’), 76.4 (C-3), 78.6 (C-3’’’), 103.5 (C-8), 104.3 (C-8’’’), 110.3 (C-6), 114.8 (C-5’’’’), 114.9 (C-5’), 115.0 (C-6’’’), 117.6 (C-6’’’’), 117.8 (C-6’), 118.2 (C-4a’’’), 122.7 (C-2’), 123.3 (C-2’’’’), \u0026nbsp;123.8 (C-4a), 125.8 (C-1’), 125.8 (C-1’’’’), 132.1 (C-5’’’), 132.9 (C-5), 141.0 (C-4’), 141.0 (C-4’’’’), 144.3 (C-3’), 144.3 (C-3’’’’), 154.5 (C-8a’’’), 156.5 (C-8a), 157.3 (C-7’’’), 158.2 (C-7); MALDI-TOFMS\u003cem\u003e\u0026nbsp;m/z\u0026nbsp;\u003c/em\u003e609.1369 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 609.1373, C\u003csub\u003e32\u003c/sub\u003eH\u003csub\u003e26\u003c/sub\u003eNaO\u003csub\u003e11\u003c/sub\u003e). All NMR data were shown in Table\u0026nbsp;5.\u003c/p\u003e\n\u003cp\u003e3-hydroxypeltogynone\u0026nbsp;(\u003cstrong\u003e10\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003eColorless crystal;\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 4.50 (2-H, 1H, \u003cem\u003es\u003c/em\u003e), 4.87 (1’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.87 (1’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.36 (8-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.56 (6-H, 1H, \u003cem\u003edd\u003c/em\u003e), 6.57 (3’-H, 1H, \u003cem\u003es\u003c/em\u003e), 6.82 (6’-H, 1H, \u003cem\u003es\u003c/em\u003e), 7.48 (5-H, 1H, \u003cem\u003ed\u003c/em\u003e);\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 66.0 (C-1’’), 68.3 (C-2), 99.4 (C-8), 105.7 (C-3), 111.4 (C-3’), 113.2 (C-4a), 113.2 (C-6), 115.7 (C-6’), 125.7 (C-2’), 125.9 (C-1’), 127.4 (C-5), 145.9 (C-4’), 146.8 (C-5’), 169.6 (C-8a), 174.5 (C-7), 195.3 (C-4); MALDI-TOFMS\u003cem\u003e\u0026nbsp;m/z\u003c/em\u003e 339.0478 [M+Na]\u003csup\u003e+\u0026nbsp;\u003c/sup\u003e(calculated for 339.0481, C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e12\u003c/sub\u003eNaO\u003csub\u003e7\u003c/sub\u003e). All NMR data were shown in Table\u0026nbsp;6.\u003c/p\u003e\n\u003cp\u003e4-methoxypeltogynol\u0026nbsp;(\u003cstrong\u003e11\u003c/strong\u003e)\u003c/p\u003e\n\u003cp\u003eColorless crystal;\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH-NMR (ppm, 600 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e) 3.57 (-OCH\u003csub\u003e3\u003c/sub\u003e, 1H, \u003cem\u003es\u003c/em\u003e), 3.70 (3-H, 1H,\u003cem\u003e\u0026nbsp;d\u003c/em\u003e), 4.54 (4-H, 1H, \u003cem\u003edd\u003c/em\u003e), 4.78 (2-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.79 (1’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 4.92 (1’’-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.36 (8-H, 1H, \u003cem\u003ed\u003c/em\u003e), 6.49 (6-H, 1H, \u003cem\u003edd\u003c/em\u003e), 6.57 (3’-H, 1H,\u003cem\u003e\u0026nbsp;s\u003c/em\u003e), 7.08 (6’-H, 1H, \u003cem\u003es\u003c/em\u003e), 7.22 (5-H, 1H, \u003cem\u003edd\u003c/em\u003e);\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC-NMR (ppm, 125 MHz,\u0026nbsp;acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e); MALDI-TOFMS\u003cem\u003em/z\u003c/em\u003e 339.0840\u0026nbsp;[M+Na]\u003csup\u003e+\u003c/sup\u003e (\u003cem\u003em/z\u003c/em\u003e 339.0845, Calculated for C\u003csub\u003e17\u003c/sub\u003eH\u003csub\u003e1\u003c/sub\u003e\u003csub\u003e 6\u003c/sub\u003e\u003csub\u003e 4 \u003c/sub\u003eNaO\u003csub\u003e6\u003c/sub\u003e). All\u0026nbsp;NMR data were shown in Table\u0026nbsp;7.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4.\u003c/strong\u003e\u003cstrong\u003e8 Effect of light exposure\u0026nbsp;to\u0026nbsp;isolated compounds\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eExcept\u0026nbsp;for\u0026nbsp;two aldehydes \u0026nbsp;(\u003cstrong\u003e2\u003c/strong\u003e, \u003cstrong\u003e8\u003c/strong\u003e), 2 mg of each isolated compound that \u0026nbsp;are \u0026nbsp;peltogynoid s was dissolved\u0026nbsp;in\u0026nbsp;0.5 ml of methanol and transferred into an NMR tube.\u0026nbsp;Discoloration\u0026nbsp;was evaluated by exposure to room light in the air\u0026nbsp;for 24h. To measure the color,\u0026nbsp;a filter paper chip cut into a circle with a diameter of 1.5 cm was impregnated\u0026nbsp;with\u0026nbsp;each methanol solvent of the isolated compounds, and the values of\u0026nbsp;\u003cem\u003ea*\u003c/em\u003e,\u0026nbsp;\u003cem\u003eb*\u003c/em\u003e, and\u0026nbsp;\u003cem\u003eL*\u003c/em\u003e before and after exposure were measured using a color meter.\u0026nbsp;\u003c/p\u003e"},{"header":"Results and discussion","content":"\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003e5.1 Light exposure behavior of extract and soluble parts\u003c/h2\u003e \u003cp\u003eFor the CIE LAB parameters, positive values of \u003cem\u003ea*\u003c/em\u003e indicate redness, while negative values indicate greenness, and positive values of \u003cem\u003eb*\u003c/em\u003e indicate yellowness, while negative values indicate blueness. If the coordinates of (\u003cem\u003ea*, b*\u003c/em\u003e) are (0, 0), it is achromatic (Supap et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Jung and Sato \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). The results of the CIE parameter measurements for the methanol extract and each soluble part are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea and Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e. At 0h of light exposure, the \u003cem\u003eL*\u003c/em\u003e values of all soluble parts, except for the \u003cem\u003en-\u003c/em\u003ehexane soluble part, were +\u0026thinsp;89 to +\u0026thinsp;95, and the \u003cem\u003ea*\u003c/em\u003e and \u003cem\u003eb*\u003c/em\u003e values were positive, indicating that all of them ranged from orange to brown. After 48 h of light exposure, the \u003cem\u003ea*\u003c/em\u003e values of the methanol extract, ether soluble part, and ethyl acetate soluble parts changed to positive values with \u003cem\u003eΔa*\u003c/em\u003e\u003csub\u003e\u003cem\u003e0h\u0026rarr;24h\u003c/em\u003e\u003c/sub\u003e of 6.5, 2.6, and 4.3, and the \u003cem\u003eb*\u003c/em\u003e values changed to negative values with \u003cem\u003eΔb*\u003c/em\u003e\u003csub\u003e\u003cem\u003e0h\u0026rarr;24h\u003c/em\u003e\u003c/sub\u003e of -27.9, -14.5, and \u0026minus;\u0026thinsp;21.3, respectively. Meanwhile, each parameter of the \u003cem\u003en\u003c/em\u003e-hexane and methanol soluble parts remained almost unchanged (\u003cem\u003eΔa*\u003c/em\u003e\u003csub\u003e\u003cem\u003e0h\u0026rarr;24h\u003c/em\u003e\u003c/sub\u003e = 0.2 and 1.5, \u003cem\u003eΔb*\u003c/em\u003e\u003csub\u003e\u003cem\u003e0h\u0026rarr;24h\u003c/em\u003e\u003c/sub\u003e = 0.0 and 0.9). Additionally, their hue values were significantly reduced (\u003cem\u003eΔh*\u003c/em\u003e\u003csub\u003e\u003cem\u003e0h\u0026rarr;24h\u003c/em\u003e\u003c/sub\u003e = -141.7, -100.0, -127.8) and \u003cem\u003eΔE\u003c/em\u003e values were increased (\u003cem\u003eΔE\u003c/em\u003e\u003csub\u003e\u003cem\u003e0h\u0026rarr;24h\u003c/em\u003e\u003c/sub\u003e = 28.6, 15.3, 21.9). These results indicate that the methanol extract, ether soluble part, and ethyl acetate soluble part were discolored purple upon exposure to room light in the air (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea). These clearly show that the precursors of the pigment compounds were mainly concentrated in the diethyl ether and ethyl acetate soluble parts.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section2\"\u003e \u003ch2\u003e5.2 Structure determination\u003c/h2\u003e \u003cp\u003e \u003cb\u003e1\u003c/b\u003e, \u003cb\u003e2\u003c/b\u003e, \u003cb\u003e4\u003c/b\u003e, and \u003cb\u003e8\u003c/b\u003e were identified as (+)-peltogynol (\u003cb\u003e1\u003c/b\u003e) (S. E. Drewes and D. G. Roux 1966), 2,4-dihydroxybenzaldehyde (\u003cb\u003e2\u003c/b\u003e) (Eun-Mi et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2007\u003c/span\u003e), (+)-mopanol (\u003cb\u003e4\u003c/b\u003e) (S. E. Drewes and D. G. Roux 1966), and syringaldehyde (\u003cb\u003e8\u003c/b\u003e) (A. Ram Kumar et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), according to previous literature data. Among them, \u003cb\u003e2\u003c/b\u003e and \u003cb\u003e8\u003c/b\u003e were isolated from this species for the first time. All compounds isolated in this study are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cdiv id=\"Sec21\" class=\"Section3\"\u003e \u003ch2\u003e5.2.1 Structure determination of monomers\u003c/h2\u003e \u003cp\u003eCompound \u003cb\u003e3\u003c/b\u003e was isolated as pale-yellow crystals. The MALDI-TOF MS analysis in the positive mode generated an [M\u0026thinsp;+\u0026thinsp;Na]\u003csup\u003e+\u003c/sup\u003e ion at \u003cem\u003em/z\u003c/em\u003e 339.0842 (calculated for C\u003csub\u003e17\u003c/sub\u003eH\u003csub\u003e16\u003c/sub\u003eNaO\u003csub\u003e6,\u003c/sub\u003e \u003cem\u003em/z\u003c/em\u003e 339.0845) indicating the molecular formula C\u003csub\u003e17\u003c/sub\u003eH\u003csub\u003e16\u003c/sub\u003eO\u003csub\u003e6\u003c/sub\u003e (Fig.S3-\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe structure was elucidated by analyzing the NMR spectra (Fig.S3-\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e to S3-6). The \u003csup\u003e1\u003c/sup\u003eH-NMR spectrum showed the presence of five phenyl group protons [\u003cem\u003eδ\u003c/em\u003e\u003csub\u003eH\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;7.23 (1H, \u003cem\u003ed\u003c/em\u003e), 6.99 (1H, \u003cem\u003ed\u003c/em\u003e), 6.84 (1H, \u003cem\u003ed\u003c/em\u003e), 6.49 (1H, \u003cem\u003edd\u003c/em\u003e), and 6.34 ppm (1H, \u003cem\u003ed\u003c/em\u003e)], four alkane protons [4.80 (1H, \u003cem\u003ed\u003c/em\u003e), 4.92 (1H, \u003cem\u003ed\u003c/em\u003e), 4.79 (1H, \u003cem\u003ed\u003c/em\u003e), 4.55 (1H, \u003cem\u003ed\u003c/em\u003e), and 3.69 ppm (1H, \u003cem\u003edd\u003c/em\u003e)], and one methoxy proton [3.60 ppm (3H, \u003cem\u003es\u003c/em\u003e)]. \u003csup\u003e13\u003c/sup\u003eC-NMR spectrum showed seventeen resonances, including twelve phenyl carbons [\u003cem\u003eδ\u003c/em\u003e\u003csub\u003eC\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;158.9, 156.4, 144.3, 141.0, 130.4, 125.6, 123.1, 117.8, 115.5, 114.6, 110.0, and 103.3 ppm], four alkane carbons [78.8, 77.5, 72.6, and 65.2 ppm], and one methoxy carbon [58.3 ppm]. For protonated carbon, the correspondences between the protons and carbon were determined based on the HMQC spectrum. COSY spectrum showed a coupled proton system attributed to H-5 (doublet, 7.23 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;7.8 Hz) and H-6 (double doublet, 6.49 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3.0, 8.4 Hz), and H-5\u0026rsquo; (doublet, 6.84 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz) and H-6\u0026rsquo; (doublet, 6.99 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz). From the coupling constants and the results of COSY analysis, the five phenyl group protons were separated into a trisubstituted benzene ring consisting of H-5 (doublet, 7.23 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;7.8 Hz), H-6 (double doublet, 6.49 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3.0, 8.4 Hz), and H-8 (doublet, 6.34 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;3.0 Hz), and a tetrasubstituted benzene ring consisting of H-5\u0026rsquo; (doublet, 6.84 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz) and H-6\u0026rsquo; (doublet, 6.99 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz) (A ring and B ring). A continuous spin system of C-2 to C-4 was observed in the COSY correlation and a series of HMBC correlations of H-2/C-1\u0026rsquo;, C-6\u0026rsquo;, H-3/C-1\u0026rsquo;\u0026rsquo;, H-4/C-4a, C-8a, and H-1\u0026rsquo;\u0026rsquo;/C-1\u0026rsquo; were assigned to construct the mopanol skeleton. The position of the methoxy group was determined based on the HMBC correlation of H-4/OCH\u003csub\u003e3\u003c/sub\u003e. Thus, the planar structure 3 was determined as 4-methoxymopanol.\u003c/p\u003e \u003cp\u003eThe relative configuration of \u003cb\u003e3\u003c/b\u003e was determined based on the coupling constant of H-2 (doublet, 4.80 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;11.4 Hz), H-3 (double doublet 3.69 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;7.8, 9.6 Hz), and H4 (doublet, 4.55 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz) as 2,3-\u003cem\u003etrans\u003c/em\u003e-3,4-\u003cem\u003etrans\u003c/em\u003e. The absolute configuration of \u003cb\u003e3\u003c/b\u003e was determined from its ECD spectrum (Fig. S3-7). The experimental ECD spectrum of \u003cb\u003e3\u003c/b\u003e showed positive Cotton effects at approximately 212 and 227 nm. This result is in good agreement with the calculated ECD spectrum of (2\u003cem\u003eR\u003c/em\u003e, 3\u003cem\u003eS\u003c/em\u003e, 4\u003cem\u003eR\u003c/em\u003e)-\u003cb\u003e3\u003c/b\u003e. Thus, the absolute configuration of \u003cb\u003e3\u003c/b\u003e was determined to be 4\u003cem\u003eR\u003c/em\u003e-methoxymopanol.\u003c/p\u003e \u003cp\u003eCompound \u003cb\u003e11\u003c/b\u003e was isolated as colorless crystals. The MALDI-TOF MS analysis in positive mode generated an [M\u0026thinsp;+\u0026thinsp;Na]\u003csup\u003e+\u003c/sup\u003e ion at \u003cem\u003em/z\u003c/em\u003e 339.0840 (calculated for C\u003csub\u003e17\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eNaO\u003csub\u003e6,\u003c/sub\u003e \u003cem\u003em/z\u003c/em\u003e 339.0845), indicating the molecular formula C\u003csub\u003e17\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eO\u003csub\u003e6\u003c/sub\u003e (Fig.S9-\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe structure was elucidated based on the analysis of the NMR spectra (Fig.S9-\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e to S9-6). \u003cb\u003e11\u003c/b\u003e was determined to be the structural isomer of \u003cb\u003e3\u003c/b\u003e, differing in the positions of the two hydroxy groups in the B ring. The \u003csup\u003e1\u003c/sup\u003eH-NMR spectrum showed two singlets of H-3\u0026rsquo; (singlet, 6.57 ppm) and H-5\u0026rsquo; (singlet, 7.08 ppm), while H-3\u0026rsquo; and H-5\u0026rsquo; of \u003cb\u003e3\u003c/b\u003e were detected as doublets. A series of HMBC correlation of H-1\u0026rsquo;\u0026rsquo;/C-3 and H-5\u0026rsquo;/C-2, and a downfield shift of H-4\u0026rsquo; (\u003cem\u003eδ\u003c/em\u003e\u003csub\u003eC\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;145.0 ppm) and H-5\u0026rsquo; (146.0 ppm) showed that \u003cb\u003e11\u003c/b\u003e retained a peltogynol skeleton. Thus, the planar structure 8 was determined to be 4-methoxypeltogynol.\u003c/p\u003e \u003cp\u003eThe relative configuration of \u003cb\u003e11\u003c/b\u003e was determined based on coupling constants of H-2 (doublet, 4.78 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;9.6 Hz), H-3 (double doublet 3.70 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4, 9.6 Hz), and H-4 (doublet, 4.54 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz) as 2,3-\u003cem\u003etrans\u003c/em\u003e-3,4-\u003cem\u003etrans\u003c/em\u003e. ECD measurement of \u003cb\u003e11\u003c/b\u003e was conducted to determine its absolute configuration, however, the Cotton effect was not observed. Therefore, only the planar structure was determined in this study.\u003c/p\u003e \u003cp\u003eCompound \u003cb\u003e10\u003c/b\u003e was isolated as colorless crystals. The MALDI-TOF MS analysis in the positive mode generated an [M\u0026thinsp;+\u0026thinsp;Na]\u003csup\u003e+\u003c/sup\u003e ion at \u003cem\u003em/z\u003c/em\u003e 339.0478 (calculated for C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e12\u003c/sub\u003eNaO\u003csub\u003e7,\u003c/sub\u003e \u003cem\u003em/z\u003c/em\u003e 339.0481), indicating the molecular formula C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e12\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003e (Fig.S8-\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe structure was elucidated based on the analysis of the NMR spectra (Fig.S8-\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e to S8-6). Comparison of the spectroscopic data of \u003cb\u003e10\u003c/b\u003e with \u003cb\u003e11\u003c/b\u003e showed that \u003cb\u003e10\u003c/b\u003e retained its mopanol skeleton. Their differences lie in the downfield shift of C-3 (\u003cem\u003eδ\u003c/em\u003e\u003csub\u003eC\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;105.7 ppm) and the change to the carbonyl region of C-4 (195.3 ppm) (See Fig.S8-\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e to 8\u0026thinsp;\u0026minus;\u0026thinsp;5). Thus, the planar structure 10 was determined to be 3-hydroxypeltogynone. The Cotton effect was not observed in the ECD measurement of \u003cb\u003e10\u003c/b\u003e. Therefore, only the planar structure was determined in this study.\u003c/p\u003e \u003cp\u003eCompound \u003cb\u003e7\u003c/b\u003e was isolated as colorless crystals. The MALDI-TOF MS analysis in the positive mode generated an [M\u0026thinsp;+\u0026thinsp;Na]\u003csup\u003e+\u003c/sup\u003e ion at \u003cem\u003em/z\u003c/em\u003e 323.0527 (calculated for C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e12\u003c/sub\u003eNaO\u003csub\u003e6,\u003c/sub\u003e \u003cem\u003em/z\u003c/em\u003e 323.0531) indicating the molecular formula C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e12\u003c/sub\u003eO\u003csub\u003e6\u003c/sub\u003e (Fig.S6-\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe structure was elucidated based on the analysis of the NMR spectra (Fig.S6-\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e to S6-6). THE NMR spectrum of \u003cb\u003e7\u003c/b\u003e was similar to that of \u003cb\u003e10\u003c/b\u003e, differing in the presence of H-3 (doublet, 4.37 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;11.4 Hz). This indicates that C-3 is a protonated carbon, whereas the C-3 of 10 is hydroxylated. Thus, the planar structure of \u003cb\u003e7\u003c/b\u003e was determined to be peltogynone.\u003c/p\u003e \u003cp\u003eThe relative configuration of \u003cb\u003e7\u003c/b\u003e was determined based on the coupling constants of H-2 (doublet, 4.56 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;11.4 Hz) and H-3 (doublet, 4.37 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;11.4 Hz) as 2,3-\u003cem\u003etrans\u003c/em\u003e. The absolute configuration of \u003cb\u003e7\u003c/b\u003e was determined from its ECD spectrum (Fig. S6-7). The experimental ECD spectrum of \u003cb\u003e7\u003c/b\u003e showed a positive Cotton effect at approximately 325, 271, 233, and 217 nm, and a negative Cotton effect at approximately 293 nm. This result is in good agreement with the calculated ECD spectrum of (2\u003cem\u003eS\u003c/em\u003e, 3\u003cem\u003eS\u003c/em\u003e)-\u003cb\u003e7\u003c/b\u003e. Thus, the absolute configuration of \u003cb\u003e7\u003c/b\u003e was determined to be 2\u003cem\u003eS\u003c/em\u003e, 3\u003cem\u003eS\u003c/em\u003e-peltogynone.\u003c/p\u003e \u003cp\u003eCompound \u003cb\u003e6\u003c/b\u003e was isolated as pale yellow crystals. The MALDI-TOF MS analysis in the positive mode generated an [M\u0026thinsp;+\u0026thinsp;Na]\u003csup\u003e+\u003c/sup\u003e ion at \u003cem\u003em/z\u003c/em\u003e 309.0739 (calculated for C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eNaO\u003csub\u003e5,\u003c/sub\u003e \u003cem\u003em/z\u003c/em\u003e 309.0739), indicating the molecular formula C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e (Fig.S5-\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe structure was elucidated based on the analysis of the NMR spectra (Fig.S5-\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e to S5-6). The \u003csup\u003e1\u003c/sup\u003eH-NMR spectrum of methanol-\u003cem\u003ed\u003c/em\u003e\u003csub\u003e\u003cem\u003e4\u003c/em\u003e\u003c/sub\u003e showed the presence of seven phenyl group protons [\u003cem\u003eδ\u003c/em\u003e\u003csub\u003eH\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;7.33 (1H, \u003cem\u003edd\u003c/em\u003e), 7.33 (1H, \u003cem\u003edd\u003c/em\u003e), 7.71 (1H, \u003cem\u003ed\u003c/em\u003e), 6.82 (1H, \u003cem\u003edd\u003c/em\u003e), 6.82 (1H, \u003cem\u003edd\u003c/em\u003e), 6.52 (1H, \u003cem\u003edd\u003c/em\u003e), and 6.32 ppm (1H, \u003cem\u003ed\u003c/em\u003e),], two alkane protons [5.12 (1H, \u003cem\u003ed\u003c/em\u003e) and 4.22 ppm (1H, \u003cem\u003ed\u003c/em\u003e)], and one methoxy proton [3.29 ppm (3H, \u003cem\u003es\u003c/em\u003e)]. \u003csup\u003e13\u003c/sup\u003eC-NMR spectrum revealed the presence of sixteen carbon signals, including twelve phenyl carbons [\u003cem\u003eδ\u003c/em\u003e\u003csub\u003eC\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;166.9, 164.8, 159.2, 130.1, 130.1, 130.1, 129.2, 116.2, 116.2, 114.0, 112.1, and 103.6 ppm], two alkane carbons [84.1 and 83.3 ppm], one carbonyl carbon [193.4 ppm], and one methoxy carbon [60.6 ppm]. A similar structure of A ring and carbonyl carbon at C-4 as \u003cb\u003e7\u003c/b\u003e was confirmed by the AMX system of protons H-5 (doublet, 7.71 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;9.6), H-6 (doublet, 6.52 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.8, 9.6), H-8 (doublet, 6.32 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.4), and the COSY correlation of H-5/C-6.\u003c/p\u003e \u003cp\u003eThe two double doublets with an integrated value of 2, H-2\u0026rsquo; and H-6\u0026rsquo; (double doublet, 7.33 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.8, 7.2 Hz), and H-3\u0026rsquo; and H-5\u0026rsquo; (double doublet, 6.82 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.8, 6.6 Hz) indicated that the B ring was a disubstituted benzene. In addition, the phenol moiety was confirmed by the downfield shift of C-4\u0026rsquo; (159.2 ppm) and a series of HMBC correlation of H-2/C-6\u0026rsquo;, H-2\u0026rsquo;/C-2, and H-3\u0026rsquo;/C-4\u0026rsquo;. The position of the methoxy group was determined based on the HMBC correlation of H-3/OCH\u003csub\u003e3\u003c/sub\u003e. Thus, the planar structure of \u003cb\u003e6\u003c/b\u003e was determined to be 3-methoxyliquiritigenin.\u003c/p\u003e \u003cp\u003eThe relative configuration of \u003cb\u003e6\u003c/b\u003e was determined based on the coupling constants of H-2 (doublet, 5.12 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;11.4 Hz) and H-3 (doublet, 4.22 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;10.2 Hz) as 2,3-\u003cem\u003etrans\u003c/em\u003e. The absolute configuration of \u003cb\u003e6\u003c/b\u003e was determined from its ECD spectrum (Fig. S5-7). The experimental ECD spectrum of \u003cb\u003e6\u003c/b\u003e showed a positive Cotton effect at approximately 331, 236, and 214 nm and a negative Cotton effect at approximately 302 nm. This result is in good agreement with the calculated ECD spectra of (2\u003cem\u003eS\u003c/em\u003e, 3\u003cem\u003eR\u003c/em\u003e)-\u003cb\u003e6\u003c/b\u003e. Thus, the absolute configuration of \u003cb\u003e6\u003c/b\u003e was determined to be 3\u003cem\u003eS\u003c/em\u003e-methoxy-2\u003cem\u003eS\u003c/em\u003e-liquiritigenin.\u003c/p\u003e \u003cp\u003eCompound \u003cb\u003e5\u003c/b\u003e was isolated as colorless crystals. The MALDI-TOF MS analysis in the positive mode generated an [M\u0026thinsp;+\u0026thinsp;Na]\u003csup\u003e+\u003c/sup\u003e ion at \u003cem\u003em/z\u003c/em\u003e 325.0688 (calculated for C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eNaO\u003csub\u003e6,\u003c/sub\u003e \u003cem\u003em/z\u003c/em\u003e 325.0688), indicating the molecular formula C\u003csub\u003e16\u003c/sub\u003eH\u003csub\u003e14\u003c/sub\u003eO\u003csub\u003e6\u003c/sub\u003e (Fig.S4-\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe structure was elucidated based on the analysis of the NMR spectra (Fig.S4-\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e to S4-6). The comparison of the spectroscopic data of \u003cb\u003e5\u003c/b\u003e and \u003cb\u003e6\u003c/b\u003e differed in terms of the coupling system in the B ring, H-2\u0026rsquo; (doublet, 7.01 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.4 Hz), H-5\u0026rsquo; (doublet, 6.75 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;7.8 Hz), and H-6\u0026rsquo; (double doublet, 6.82 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.8, 7.8 Hz). The catechol moiety was confirmed as the B ring by two downfield shifted carbon C-3\u0026rsquo; (146.6 ppm) and C-4\u0026rsquo; (146.1 ppm) and a series of HMBC correlation of H-2/C-2\u0026rsquo;, C-6\u0026rsquo;, H-5\u0026rsquo;/C-3\u0026rsquo;, and H-6\u0026rsquo;/C-4\u0026rsquo;. Thus, the planar structure of \u003cb\u003e5\u003c/b\u003e was determined to be 3\u003cem\u003eR\u003c/em\u003e-methoxybutin.\u003c/p\u003e \u003cp\u003eThe relative configuration of \u003cb\u003e5\u003c/b\u003e was determined based on the coupling constants of H-2 (doublet, 5.31 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.8 Hz) and H-3 (doublet, 3.73 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1.8 Hz) as 2,3-\u003cem\u003ecis\u003c/em\u003e. The absolute configuration of \u003cb\u003e5\u003c/b\u003e was determined from its ECD spectrum (Fig. S4-7). The experimental ECD spectrum of \u003cb\u003e5\u003c/b\u003e showed positive Cotton effects at approximately 324, 269, 233, and 217 nm, and a negative Cotton effect at approximately 293 nm. This result is in good agreement with the calculated ECD spectrum of (2\u003cem\u003eS\u003c/em\u003e, 3\u003cem\u003eR\u003c/em\u003e)-\u003cb\u003e5\u003c/b\u003e. Thus, the absolute configuration of \u003cb\u003e6\u003c/b\u003e was determined to be 3\u003cem\u003eR\u003c/em\u003e-methoxy-(+)-butin.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec22\" class=\"Section3\"\u003e \u003ch2\u003e5.2.2 Structure determination of dimer\u003c/h2\u003e \u003cp\u003eCompound \u003cb\u003e9\u003c/b\u003e was isolated as colorless crystals. The MALDI-TOF MS analysis in the positive mode generated an [M\u0026thinsp;+\u0026thinsp;Na]\u003csup\u003e+\u003c/sup\u003e ion at \u003cem\u003em/z\u003c/em\u003e 609.1369 (calculated for C\u003csub\u003e32\u003c/sub\u003eH\u003csub\u003e26\u003c/sub\u003eNaO\u003csub\u003e11,\u003c/sub\u003e \u003cem\u003em/z\u003c/em\u003e 609.1373), indicating the molecular formula C\u003csub\u003e32\u003c/sub\u003eH\u003csub\u003e26\u003c/sub\u003eNaO\u003csub\u003e11\u003c/sub\u003e (Fig.S7-\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe structure was elucidated based on the analysis of the NMR spectra (Fig.S7-\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e to S7-6). The \u003csup\u003e1\u003c/sup\u003eH-NMR spectrum showed the presence of nine phenyl group protons [\u003cem\u003eδ\u003c/em\u003e\u003csub\u003eH\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;7.17 (1H, \u003cem\u003ed\u003c/em\u003e), 7.10 (1H, \u003cem\u003ed\u003c/em\u003e), 6.95 (1H, \u003cem\u003ed\u003c/em\u003e), 6.94 (1H, \u003cem\u003ed\u003c/em\u003e), 6.88 (1H, \u003cem\u003ed\u003c/em\u003e), 6.86 (1H, \u003cem\u003es\u003c/em\u003e), 6.56 (1H, \u003cem\u003ed\u003c/em\u003e), 6.53 (1H, \u003cem\u003edd\u003c/em\u003e), and 6.52 ppm (1H, \u003cem\u003es\u003c/em\u003e)] and ten alkane protons [5.02 (1H, \u003cem\u003ed\u003c/em\u003e), 5.00 (1H, \u003cem\u003ed\u003c/em\u003e), 4.96 (1H, \u003cem\u003ed\u003c/em\u003e), 4.92 (1H, \u003cem\u003ed\u003c/em\u003e), 4.87 (1H, \u003cem\u003ed\u003c/em\u003e), 4.84 (1H, \u003cem\u003ed\u003c/em\u003e), 4.80 (1H, \u003cem\u003ed\u003c/em\u003e), 4.71 (1H, br \u003cem\u003ed\u003c/em\u003e), 4.18 (1H, \u003cem\u003edd\u003c/em\u003e), and 3.55 ppm (1H, \u003cem\u003edd\u003c/em\u003e)]. The \u003csup\u003e13\u003c/sup\u003eC-NMR spectrum showed thirty two resonances, including twenty four phenyl carbons [\u003cem\u003eδ\u003c/em\u003e\u003csub\u003eC\u003c/sub\u003e\u0026thinsp;=\u0026thinsp;158.2, 157.3, 156.5, 154.5, 144.3, 144.3, 141.0, 141.0, 132.9, 132.1, 125.9, 125.9, 123.8, 123.3, 122.7, 118.2, 117.8, 117.6, 115.0, 114.9, 114.8, 110.3, 104.3, and 103.5 ppm] and eight alkane carbons [78.6, 76.4, 72.6, 69.8, 67.6, 65.7, 65.4, and 39.6 ppm]. For protonated carbon, the correspondences between the protons and the carbons were determined based on the HMQC spectrum. The COSY spectrum exhibited a coupled proton systems attributed to H-5 (doublet, 6.88 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz) and H-6 (double doublet, 6.53 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.5, 8.2 Hz), H-5\u0026rsquo; (doublet, 6.83 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz) and H-6\u0026rsquo; (doublet, 6.99 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz), and H-5\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo; (doublet, 6.95 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz) and H-6\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo; (doublet, 7.10 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.8 Hz), and two of three coupling protons of H-2 (doublet, 5.00 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;9.9 Hz), H-3 (double doublet, 4.18 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;5.9, 9.8 Hz), H-4 (doublet, 4.84 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;5.9 Hz), and H-2\u0026rsquo;\u0026rsquo;\u0026rsquo; (doublet, 4.87 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;10.0 Hz), H-3\u0026rsquo;\u0026rsquo;\u0026rsquo; (double doublet, 3.55 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.6, 9.9 Hz), and H-4\u0026rsquo;\u0026rsquo;\u0026rsquo; (doublet, 4.72 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz). These data indicate that \u003cb\u003e9\u003c/b\u003e is a flavonoid dimer.\u003c/p\u003e \u003cp\u003eOne of the mopanol units was confirmed by a series of HMBC of H-3\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo;/C-1\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo;, H-5\u0026rsquo;\u0026rsquo;\u0026rsquo;/C-4\u0026rsquo;\u0026rsquo;\u0026rsquo;, H-6\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo;/C-2\u0026rsquo;\u0026rsquo;\u0026rsquo;, and H-1\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo;/C-1\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo; with a difference of absence of H-6\u0026rsquo;\u0026rsquo;\u0026rsquo;. Another mopanol unit was determined by the HMBC correlations of H-3/C-1\u0026rsquo;, H-4/C-4a, H-1\u0026rsquo;\u0026rsquo;\u0026rsquo;/C-3, C-2\u0026rsquo;, and C-3\u0026rsquo; without a hydroxy group at C-4. The binding mode of these two molecules of mopanol was determined by the HMBC correlations of H-4/C-5\u0026rsquo;\u0026rsquo;\u0026rsquo;, C-6\u0026rsquo;\u0026rsquo;\u0026rsquo;, and C-7\u0026rsquo;\u0026rsquo;\u0026rsquo; to be C-4 (39.6 ppm) to C-6\u0026rsquo;\u0026rsquo;\u0026rsquo; (110.3 ppm). Thus, the planar structure of \u003cb\u003e9\u003c/b\u003e was determined to be mopanol-(4, 6)-mopanol.\u003c/p\u003e \u003cp\u003eThe relative configuration of each mopanol units in \u003cb\u003e9\u003c/b\u003e was determined based on the coupling constants. The relative configuration of one of the mopanol units (composed of C-1 to C-1\u0026rsquo;\u0026rsquo;) was determined to be 2,3-\u003cem\u003etrans\u003c/em\u003e-3,4-\u003cem\u003ecis\u003c/em\u003e based on the coupling constants of H-2 (doublet, 5.00 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;9.9 Hz), H-3 (double doublet, 4.18 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;5.9, 9.8 Hz), and H-4 (doublet, 4.84 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;5.9 Hz). Another mopanol moiety (composed of C-1\u0026rsquo;\u0026rsquo;\u0026rsquo; to C-1\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo;\u0026rsquo;) was determined to be 2,3-\u003cem\u003etrans\u003c/em\u003e-3,4-\u003cem\u003etrans\u003c/em\u003e based on the coupling constants of H-2\u0026rsquo;\u0026rsquo;\u0026rsquo; (doublet, 4.87 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;10.0 Hz), H-3\u0026rsquo;\u0026rsquo;\u0026rsquo; (double doublet, 3.55 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.6, 9.9 Hz), and H-4\u0026rsquo;\u0026rsquo;\u0026rsquo; (doublet, 4.72 ppm, \u003cem\u003eJ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8.4 Hz). The absolute configuration of \u003cb\u003e9\u003c/b\u003e was determined from its ECD spectrum (Fig. S7-7). The experimental ECD spectrum of \u003cb\u003e9\u003c/b\u003e shows a positive Cotton effect at approximately 217 nm and a negative cotton effect at approximately 206 nm. This result is in good agreement with the calculated ECD spectrum of (2\u003cem\u003eR\u003c/em\u003e, 3\u003cem\u003eS\u003c/em\u003e, 4\u003cem\u003eS\u003c/em\u003e, 2\u0026rsquo;\u0026rsquo;\u0026rsquo;\u003cem\u003eR\u003c/em\u003e, 3\u0026rsquo;\u0026rsquo;\u0026rsquo;\u003cem\u003eS\u003c/em\u003e, 4\u0026rsquo;\u0026rsquo;\u0026rsquo;\u003cem\u003eR\u003c/em\u003e)-\u003cb\u003e9\u003c/b\u003e. Thus, the absolute configuration of \u003cb\u003e9\u003c/b\u003e was determined to be (+)-mopanol B-(4β\u0026rarr;6\u0026rsquo;\u0026rsquo;\u0026rsquo;)-(+)-mopanol. A dimer composed of peltogynoids was isolated and structurally determined for the first time in this study.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec23\" class=\"Section2\"\u003e \u003ch2\u003e5.3 Effect of light exposure to isolated compounds\u003c/h2\u003e \u003cp\u003eBefore being exposed to room light in the air, \u003cb\u003e5\u003c/b\u003e, \u003cb\u003e7\u003c/b\u003e, \u003cb\u003e9\u003c/b\u003e, \u003cb\u003e10\u003c/b\u003e, and \u003cb\u003e11\u003c/b\u003e were colorless, and \u003cb\u003e1\u003c/b\u003e, \u003cb\u003e3\u003c/b\u003e, \u003cb\u003e4\u003c/b\u003e, and \u003cb\u003e6\u003c/b\u003e ranged from pale yellow to yellow. After these methanol solutions were exposed to room light and air for 24h, only (+)-peltogynol (\u003cb\u003e1\u003c/b\u003e) and (+)-mopanol (\u003cb\u003e4\u003c/b\u003e) showed purple discoloration (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb). The color changes of all flavonoids were confirmed using CIE LAB parameters (Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e). Immediately after isolation, all compounds showed positive \u003cem\u003ea*\u003c/em\u003e and \u003cem\u003eb*\u003c/em\u003e values, hile only the \u003cem\u003eb*\u003c/em\u003e values of (+)-peltogynol (\u003cb\u003e1\u003c/b\u003e) and (+)-mopanol (4) changed to negative values (-0.7 and \u0026minus;\u0026thinsp;1.8, respectively) after light exposure. The \u003cem\u003eh\u003c/em\u003e\u003csup\u003e\u003cem\u003e*\u003c/em\u003e\u003c/sup\u003e values (Δ\u003cem\u003eh\u003c/em\u003e\u003csup\u003e\u003cem\u003e*\u003c/em\u003e\u003c/sup\u003e\u003csub\u003e\u003cem\u003e0h\u0026rarr;24h\u003c/em\u003e\u003c/sub\u003e) of (+)-peltogynol (\u003cb\u003e1\u003c/b\u003e) and (+)-mopanol (\u003cb\u003e4\u003c/b\u003e) changed to -54.9 and \u0026minus;\u0026thinsp;75.8, respectively, while those of other compounds remained between \u0026minus;\u0026thinsp;0.7 and 5.6. These results suggested that (+)-peltogynol (\u003cb\u003e1\u003c/b\u003e) and (+)-mopanol (\u003cb\u003e4\u003c/b\u003e) are precursors to pigment compounds among isolated compounds in this study. These compounds have a hetero-six-membered ring (D ring) and a hydroxyl group at C-4 in \u003cem\u003eR\u003c/em\u003e-configuration. In addition, C-2, C-3, and C-4 were chiral carbons with 2\u003cem\u003eR\u003c/em\u003e, 3\u003cem\u003eS\u003c/em\u003e, 4\u003cem\u003eR\u003c/em\u003e configuration. These structural characteristics are similar to the structure of leucoanthocyanidins. Leucoanthocyanidins are easily oxidized by organic acids or air and undergo structural changes to anthocyanidins \u003cem\u003evia\u003c/em\u003e the elimination of the 4-hydroxyl group (Clark-Lewis and Williams \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1967\u003c/span\u003e). Scince (+)-peltogynol (\u003cb\u003e1\u003c/b\u003e) and (+)-mopanol (\u003cb\u003e4\u003c/b\u003e) both have a hydroxyl group at the 4-hydroxyl group, it is possible that the similar structural change could occur to generate anthocyanidins. The newly isolated compound \u003cb\u003e9\u003c/b\u003e was thought to be a proanthocyanidin generated by an intermediate that formed a bond at C-4 with (+)-mopanol at C-6, providing evidence for this mechanism.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn this study, five new peltogynoids and two new flavanones were isolated with four known compounds from the heartwood of \u003cem\u003eP. mexicana\u003c/em\u003e. This study aimed to identify compounds related to heartwood discoloration as precursors to pigment compounds. Among the isolated compounds, (+)-peltogynol (\u003cb\u003e1\u003c/b\u003e) and (+)-mopanol (\u003cb\u003e4\u003c/b\u003e) contributed to the discoloration to reddish and blueish purple, respectively, upon exposure to room light in the air. In terms of their CIE LAB parameters, the \u003cem\u003eb*\u003c/em\u003e values of these two compounds decreased and their \u003cem\u003ea*\u003c/em\u003e values increased significantly. These results showed that discoloration was accelerated by exposure to room light in the air for both the methanol extract and the isolated compounds. These two compounds possess a sub-structure similar to that of flavan-3,4-\u003cem\u003etrans\u003c/em\u003e-diol. These structural features provide insights into the mechanism of discoloration in \u003cem\u003eP. Mexicana\u003c/em\u003e, and the heartwood contains anthocyanin-like pigment compounds. However, the isolation of dimer compound \u003cb\u003e9\u003c/b\u003e is believed to contribute greatly to the elucidation of the structure of the pigment compound. In other words, it is speculated that peltogynol and mopanol are converted to anthocyanidins through quinone methides by air oxidation in the presence of light, and that the unstable structures react to form dimers, oligomers, and polymers to form pigment structures.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eTY conducted experiment and wrote the manuscript. KY and TM supervised the study and reviewed the manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThis work was financially supported by JST SPRING, Grant Number JPMJSP2125. The author would like to take this opportunity to thank the \u0026ldquo;Interdisciplinary Frontier Next Generation Researcher Program of the Tokai Higher Education and Research System.\u0026rdquo;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eA. Ram Kumar, S. Selvaraj, K.S. 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Vib Spectrosc 28:243\u0026ndash;249. https://doi.org/10.1016/S0924-2031(01)00138-2\u003c/li\u003e\n\u003cli\u003eDo LTM, Aree T, Siripong P, et al (2016) Bougainvinones A-H, Peltogynoids from the Stem Bark of Purple Bougainvillea spectabilis and Their Cytotoxic Activity. J Nat Prod 79:939\u0026ndash;945. https://doi.org/10.1021/ACS.JNATPROD.5B00996/SUPPL_FILE/NP5B00996_SI_003.PDF\u003c/li\u003e\n\u003cli\u003eE. Drewes S, Mashimbye MJ, Field JS, Ramesar N (1991) 11,11-dimethyl-1,3,8,10-tetrahydroxy-9-methoxypeltogynan and three pentacyclic triterpenes from Cassine transvaalensis. Phytochemistry 30:3490\u0026ndash;3493. https://doi.org/10.1016/0031-9422(91)83243-E\u003c/li\u003e\n\u003cli\u003eEun-Mi A, Sang-Jae P, Won-Cheol C, et al (2007) Antioxidant Activity of Isolated Compounds from the Heartwoods of Rhus verniciflua. J Korean SocAppl biol Chem 50:358\u0026ndash;361\u003c/li\u003e\n\u003cli\u003eG. M. Robinson, R. Robinson (1935) Leuco-anthocyanins and leuco-anthocyanidins. Part I. The isolation of peltogynol and its molecular structure. J Chem Soc 744\u0026ndash;752. https://doi.org/10.1039/JR9350000744\u003c/li\u003e\n\u003cli\u003eGuti\u0026eacute;rrez-Mac\u0026iacute;as P, Peralta-Cruz J, Borja-de-la-Rosa A, et al (2016) Peltomexicanin, a Peltogynoid Quinone Methide from Peltogyne Mexicana Mart\u0026iacute;nez Purple Heartwood. Molecules 2016, Vol 21, Page 186 21:186. https://doi.org/10.3390/MOLECULES21020186\u003c/li\u003e\n\u003cli\u003eHassall CH, Weatherston J (1965) 512. The absolute configuration of the leucoanthocyanidin, peltogynol. Journal of the Chemical Society (Resumed) 2844\u0026ndash;2849. https://doi.org/10.1039/JR9650002844\u003c/li\u003e\n\u003cli\u003eJanet V-A, Marlene B-M, Roberto CA-N, et al (2023) Demographic, spatial, and ecological aspects of Peltogyne mexicana - a threatened species \u0026ndash; Under different extraction conditions in southern M\u0026eacute;xico. Trees, Forests and People 14:100427. https://doi.org/10.1016/J.TFP.2023.100427\u003c/li\u003e\n\u003cli\u003eJung H, Sato T (2013) Comparison between the Color Properties of Whiteness Index and Yellowness Index on the CIELAB. Textile Coloration and Finishing 25:241\u0026ndash;246. https://doi.org/10.5764/TCF.2013.25.4.241\u003c/li\u003e\n\u003cli\u003eKim DS, Baek NI, Oh SR, et al (1997) NMR assignment of brazilein. Phytochemistry 46:177\u0026ndash;178. https://doi.org/10.1016/S0031-9422(96)00874-6\u003c/li\u003e\n\u003cli\u003eLaver ML, Arvey SW (1996) Chemical brown staining of Douglas-fir wood: Light and oxygen susceptibility of extractives. For Prod J 46:96\u0026ndash;101\u003c/li\u003e\n\u003cli\u003eMarcos C de MP, Luc APS, Thierry D, Carlito Calil J (2021) Doweled cross laminated timber: Experimental and analytical study. Constr Build Mater 273:121820. https://doi.org/10.1016/J.CONBUILDMAT.2020.121820\u003c/li\u003e\n\u003cli\u003eMathew S, Zhang K, Zhou X, et al (2023) Myrtinols A\u0026ndash;F: New Anti-Inflammatory Peltogynoid Flavonoid Derivatives from the Leaves of Australian Indigenous Plant Backhousia myrtifolia. Molecules 28:2160. https://doi.org/10.3390/MOLECULES28052160/S1\u003c/li\u003e\n\u003cli\u003eMitsunaga T, Kondo R, Imamura H (1987a) The chemistry of the color of wood. IV. The phenolic consistuent contributes to the coloration of murasakitagayasan (Millettia sp.) heartwood. Mokuzai Gakkaishi Journal of the Japan Wood Research Society 33:239\u0026ndash;245\u003c/li\u003e\n\u003cli\u003eMitsunaga T, Kondo R, Imamura H (1987b) The chemistry of the color of wood. III. The isoflavonoids of the heartwood of murasakitagayasan (Millettia sp.). Mokuzai Gakkaishi Journal of the Japan Wood Research Society 33(3): 234-238 33:234\u0026ndash;238\u003c/li\u003e\n\u003cli\u003eM.J. Frisch, G.W. Trucks, H.B. Schlegel, et al (2016) Gaussian 16W, Revision C.01\u003c/li\u003e\n\u003cli\u003ePaulina G-M, Cinthya GG-Z, Leticia G-S, Cynthia O-P (2019) Purple pigment from Peltogyne mexicana heartwood as a potential colorant for food. J Food Sci Technol 56:3225\u0026ndash;3238\u003c/li\u003e\n\u003cli\u003eS. E. Drewes, D. G. Roux (1967) Isolation of mopanin from Colophospermum mopane and interrelation of flavonoid components of Peltogyne spp. Journal of the Chemical Society C: Organic 1407\u0026ndash;1410. https://doi.org/10.1039/J39670001407\u003c/li\u003e\n\u003cli\u003eS. E. Drewes, D. G. Roux (1966) Stereochemistry and biogenesis of mopanols and peltogynols and associated flavanoids from Colophospermum mopane. Journal of the Chemical Society C: Organic 1644\u0026ndash;1653. https://doi.org/10.1039/J39660001644\u003c/li\u003e\n\u003cli\u003eSupap N, Anuchita M, Sirirat D (2012) Application of Functional Colorant Prepared from Black Rice Bran in Yogurt. APCBEE Procedia 2:62\u0026ndash;67. https://doi.org/10.1016/J.APCBEE.2012.06.012\u003c/li\u003e\n\u003cli\u003eT. Bruhn, A. Schauml\u0026ouml;ffel, Y. Hemberger, G. Pescitelli (2017) SpecDis Version 1.71\u003c/li\u003e\n\u003cli\u003eW. R. Chan, W. G. C. Forsyth, C. H. Hassall (1958) The constitution of the leucoanthocyanidin, peltogynol. Journal of the Chemical Society (Resumed) 3174\u0026ndash;3179. https://doi.org/10.1039/JR9580003174\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1 \u003csup\u003e1\u003c/sup\u003eH and \u003csup\u003e13\u003c/sup\u003eC chemical shifts and 2D NMR correlation of \u003cstrong\u003e3\u003c/strong\u003e in acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003e (\u003cem\u003e\u0026delta;\u003c/em\u003e in ppm, \u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003ePosition\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eH\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003cp\u003e(\u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eC\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\n \u003cp\u003eCOSY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003eHMBC\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\" style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e4.80\u003cem\u003e\u0026nbsp;d\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 11.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e72.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 12.9032%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e1\u0026rsquo;, 2\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e3.69\u003cem\u003e\u0026nbsp;dd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 7.8, 9.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e77.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\n \u003cp\u003e2, 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e1\u0026rdquo;, 2, 4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e4.55 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 8.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e78.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e-OCH\u003csub\u003e3\u003c/sub\u003e, 3, 4a, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e115.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e7.23 \u003cem\u003ed\u0026nbsp;\u003c/em\u003e1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u0026nbsp;\u003c/em\u003e= 7.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e130.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e4, 7, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e6.49\u003cem\u003e\u0026nbsp;dd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 3.0, 8.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e110.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e4a, 7, 8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e158.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\" style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e6.34 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 3.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e103.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 12.9032%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e4a, 6, 7, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e8a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e156.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e1\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e125.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e2\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e123.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e3\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e141.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e144.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e6.84 d 1H\u003cbr\u003e\u003cem\u003eJ\u003c/em\u003e=8.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e114.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\n \u003cp\u003e6\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e1\u0026rsquo;, 3\u0026rsquo;, 4\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e6.99 d 1H\u003cbr\u003e\u003cem\u003eJ\u003c/em\u003e=8.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e117.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\n \u003cp\u003e5\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e2, 5\u0026rsquo;, 2\u0026rsquo;, 4\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e1\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e4.79 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 4.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e65.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\n \u003cp\u003e1\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e3, 1\u0026rsquo;, 2\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e4.92 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 4.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\n \u003cp\u003e1\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e3, 1\u0026rsquo;, 2\u0026rsquo;, 3\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 15.8358%;\"\u003e\n \u003cp\u003e-OCH\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.4076%;\"\u003e\n \u003cp\u003e3.60 \u003cem\u003es\u0026nbsp;\u003c/em\u003e3H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 17.8886%;\"\u003e\n \u003cp\u003e58.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 12.9032%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 31.9648%;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 2 \u003csup\u003e1\u003c/sup\u003eH and \u003csup\u003e13\u003c/sup\u003eC chemical shifts and 2D NMR correlation of \u003cstrong\u003e5\u003c/strong\u003e in methanol-\u003cem\u003ed\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e (\u003cem\u003e\u0026delta;\u003c/em\u003e in ppm, \u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"78%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003ePosition\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eH\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003cp\u003e(\u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eC\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003eCOSY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003eHMBC\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e5.31\u003cem\u003e\u0026nbsp;d\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e82.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e1\u0026apos;, 2\u0026apos;, 6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e3.73 \u003cem\u003ed\u0026nbsp;\u003c/em\u003e1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 1.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e82.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e-OCH3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e190.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e113.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e7.72 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u0026nbsp;\u003c/em\u003e= 9.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e130.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e4, 7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e6.52 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.4, 9.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e112.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e4a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e166.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e6.37 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e103.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e8a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e165.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e1\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e129.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e2\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e7.01 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e115.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e2, 3\u0026apos;, 6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e3\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e146.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e146.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e6.75 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 7.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e115.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e1\u0026apos;, 4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e6.82 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 1.8, 7.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e120.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e2, 4\u0026apos;, 5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e-OCH\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"22.448979591836736%\"\u003e\n \u003cp\u003e3.31\u003cem\u003e\u0026nbsp;s\u003c/em\u003e 3H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e59.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"19.387755102040817%\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 3 \u003csup\u003e1\u003c/sup\u003eH and \u003csup\u003e13\u003c/sup\u003eC chemical shifts and 2D NMR correlation of \u003cstrong\u003e6\u003c/strong\u003e in methanol-\u003cem\u003ed\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e (\u003cem\u003e\u0026delta;\u003c/em\u003e in ppm, \u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003ePosition\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eH\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003cp\u003e(\u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eC\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCOSY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eHMBC\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5.12 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 11.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e84.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3, 6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.22 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 10.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e83.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2, -OCH\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"\"\u003e\n \u003cp\u003e193.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e114.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7.71 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u0026nbsp;\u003c/em\u003e= 9.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e130.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4, 7, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.52 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 1.8, 9.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e112.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4a, 8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e166.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\"\u003e\n \u003cp\u003e6.32 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\"\u003e\n \u003cp\u003e103.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"\"\u003e\n \u003cp\u003e6, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e8a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e164.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e1\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e129.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e2\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7.33\u003cem\u003e\u0026nbsp;dd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 1.8, 7.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e130.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2, 4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.82 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 1.8, 6.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e116.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1\u0026apos;, 4\u0026apos;, 5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e159.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.82 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 1.8, 6.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e116.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u0026apos;, 4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7.33 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 1.8, 7.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e130.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2, 4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e-OCH\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.29 \u003cem\u003es\u003c/em\u003e 3H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e60.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 4 \u003csup\u003e1\u003c/sup\u003eH and \u003csup\u003e13\u003c/sup\u003eC chemical shifts and 2D NMR correlation of \u003cstrong\u003e7\u003c/strong\u003e in methanol-\u003cem\u003ed\u003csub\u003e4\u003c/sub\u003e\u003c/em\u003e (\u003cem\u003e\u0026delta;\u003c/em\u003e in ppm, \u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003ePosition\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eH\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003cp\u003e(\u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eC\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\n \u003cp\u003eCOSY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 22.1477%;\"\u003e\n \u003cp\u003eHMBC\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e4.56 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 11.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e76.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 22.1477%;\"\u003e\n \u003cp\u003e3, 4, 1\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\" style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e4.37 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 11.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e77.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 14.7651%;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 22.1477%;\"\u003e\n \u003cp\u003e4, 1\u0026apos;, 1\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\" style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 24.4966%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e191.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 22.1477%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e114.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 22.1477%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\" style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e7.75\u003cem\u003e\u0026nbsp;d\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u0026nbsp;\u003c/em\u003e= 9.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e130.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 14.7651%;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 22.1477%;\"\u003e\n \u003cp\u003e4, 7, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\" style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e6.56 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.4, 9.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e112.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 14.7651%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 22.1477%;\"\u003e\n \u003cp\u003e4a, 8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e166.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 22.1477%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\" style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e6.46 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e103.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 22.1477%;\"\u003e\n \u003cp\u003e6, 7, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e8a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e164.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 22.1477%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e1\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e124.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 22.1477%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\" style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e2\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 24.4966%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e126.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 22.1477%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e3\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e6.50 \u003cem\u003es\u003c/em\u003e 1H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e111.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 22.1477%;\"\u003e\n \u003cp\u003e1\u0026apos;, 4\u0026apos;, 1\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e146.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 22.1477%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e147.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 22.1477%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e7.06 \u003cem\u003es\u003c/em\u003e 1H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e113.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 22.1477%;\"\u003e\n \u003cp\u003e2, 2\u0026apos;, 5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 18.1208%;\"\u003e\n \u003cp\u003e1\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e4.80 \u003cem\u003ed\u003c/em\u003e 2H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 20.4698%;\"\u003e\n \u003cp\u003e69.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 14.7651%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 22.1477%;\"\u003e\n \u003cp\u003e3, 1\u0026apos;, 2\u0026apos;, 3\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 24.4966%;\"\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 14.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable 5 is available in the Supplementary Files section.\u003c/p\u003e\n\u003cp\u003eTable 6 \u003csup\u003e1\u003c/sup\u003eH and \u003csup\u003e13\u003c/sup\u003eC chemical shifts and 2D NMR correlation of \u003cstrong\u003e10\u003c/strong\u003e in acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e (\u003cem\u003e\u0026delta;\u003c/em\u003e in ppm, \u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"\" style=\"width: 18.5315%;\"\u003e\n \u003cp\u003ePosition\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 25.5245%;\"\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eH\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003cp\u003e(\u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eC\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 15.3846%;\"\u003e\n \u003cp\u003eCOSY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"\" style=\"width: 19.2308%;\"\u003e\n \u003cp\u003eHMBC\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\n \u003cp\u003e4.50\u003cem\u003e\u0026nbsp;s\u003c/em\u003e 1H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e68.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\n \u003cp\u003e3, 1\u0026apos;, 6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e105.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e195.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e113.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\n \u003cp\u003e7.48 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u0026nbsp;\u003c/em\u003e= 7.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e127.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\n \u003cp\u003e4, 7, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\n \u003cp\u003e6.56 \u003cem\u003edd\u0026nbsp;\u003c/em\u003e1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.0\u003cem\u003e,\u003c/em\u003e 7.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e113.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\n \u003cp\u003e4a, 8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e174.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\n \u003cp\u003e6.36 \u003cem\u003ed\u0026nbsp;\u003c/em\u003e1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e99.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\n \u003cp\u003e7, 4a, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e8a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e169.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e1\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e125.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e2\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e125.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e3\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\n \u003cp\u003e6.57\u003cem\u003e\u0026nbsp;s\u003c/em\u003e 1H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e111.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\n \u003cp\u003e2\u0026apos;, 4\u0026apos;, 1\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e145.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e146.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\n \u003cp\u003e6.82\u003cem\u003e\u0026nbsp;s\u003c/em\u003e 1H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e115.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd style=\"width: 19.2308%;\"\u003e\n \u003cp\u003e1\u0026apos;, 2\u0026apos;, 5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 18.5315%;\"\u003e\n \u003cp\u003e1\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\n \u003cp\u003e4.87 \u003cem\u003ed\u0026nbsp;\u003c/em\u003e1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 14.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 21.3287%;\"\u003e\n \u003cp\u003e66.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 15.3846%;\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 19.2308%;\"\u003e\n \u003cp\u003e3, 2\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 25.5245%;\"\u003e\n \u003cp\u003e4.87 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 14.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 7 \u003csup\u003e1\u003c/sup\u003eH and \u003csup\u003e13\u003c/sup\u003eC chemical shifts and 2D NMR correlation of \u003cstrong\u003e11\u003c/strong\u003e in acetone-\u003cem\u003ed\u003csub\u003e6\u003c/sub\u003e\u003c/em\u003e (\u003cem\u003e\u0026delta;\u003c/em\u003e in ppm, \u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003ePosition\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eH\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003cp\u003e(\u003cem\u003eJ\u003c/em\u003e in Hz)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026delta;\u003csub\u003eC\u003c/sub\u003e (ppm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eCOSY\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eHMBC\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.78 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 9.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e72.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3, 1\u0026rsquo;, 2\u0026rsquo;, 3\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.70 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 8.4, 9.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e78.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2, 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1\u0026rsquo;\u0026rsquo;, 2, 4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.54 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 8.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e78.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e-OCH\u003csub\u003e3\u003c/sub\u003e, 3, 4a, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e4a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e115.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7.22 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u0026nbsp;\u003c/em\u003e= 8.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e130.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4, 7, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.49 \u003cem\u003edd\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.4, 8.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e110.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e158.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.36 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u003cem\u003eJ\u003c/em\u003e = 2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e103.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6, 8a\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e8a\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e156.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e1\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e127.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e2\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e124.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.57\u003cem\u003e\u0026nbsp;s\u0026nbsp;\u003c/em\u003e1H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e111.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2\u0026rsquo;, 5\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e4\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e145.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e5\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e146.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7.08 \u003cem\u003es\u003c/em\u003e 1H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e113.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2, 1\u0026rsquo;, 4\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e1\u0026apos;\u0026apos;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.79 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003cem\u003eJ\u003c/em\u003e = 10.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e68.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e1\u0026rsquo;\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e2\u0026rsquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e4.92 \u003cem\u003ed\u003c/em\u003e 1H\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003cem\u003eJ\u003c/em\u003e = 10.2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e-OCH\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.57 \u003cem\u003es\u003c/em\u003e 1H\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e58.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"wood-science-and-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"wsat","sideBox":"Learn more about [Wood Science and Technology](http://link.springer.com/journal/226)","snPcode":"226","submissionUrl":"https://submission.nature.com/new-submission/226/3","title":"Wood Science and Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"flavonoid, Peltogyne mexicana, peltogynoid, pigment, precursor","lastPublishedDoi":"10.21203/rs.3.rs-4759481/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4759481/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eFour new peltogynoid monomers (\u003cstrong\u003e3\u003c/strong\u003e, \u003cstrong\u003e7\u003c/strong\u003e, \u003cstrong\u003e10\u003c/strong\u003e, \u003cstrong\u003e11\u003c/strong\u003e), a new peltogynoid dimer (\u003cstrong\u003e9\u003c/strong\u003e), and two new flavanones (\u003cstrong\u003e5\u003c/strong\u003e, \u003cstrong\u003e6\u003c/strong\u003e) were isolated from the heartwood of \u003cem\u003ePeltogyne mexiacana\u003c/em\u003e, along with two known peltogynoids (\u003cstrong\u003e1\u003c/strong\u003e, \u003cstrong\u003e4\u003c/strong\u003e) and two known aldehydes (\u003cstrong\u003e2\u003c/strong\u003e, \u003cstrong\u003e8\u003c/strong\u003e). The structures of the isolated compounds were determined using NMR and MALDI-TOF MS analysis. The discoloration of the methanol solutions of the isolated peltogynoids and flavanones was examined by exposing them to room light in the air. The methanol solutions of (+)-peltogynol (\u003cstrong\u003e1\u003c/strong\u003e) and (+)-mopanol (\u003cstrong\u003e4\u003c/strong\u003e) discolored to reddish and bluish purple, respectively. After discoloration, the \u003cem\u003eb*\u003c/em\u003e values of these compounds decreased significantly from 12.1 and 19.1 to -0.7 and − 1.8, respectively. These precursors of pigment compounds \u003cstrong\u003e1\u003c/strong\u003e and \u003cstrong\u003e4\u003c/strong\u003e have a catechol moiety in the B ring, and a hetero-six-membered ring (D ring) connecting the B and C ring of flavan-3,4-diol \u003cem\u003evia\u003c/em\u003e an oxyethylene bridge, which is similar to the structure of leucoanthocyanidin. These results led to the hypothesis that the metabolized pigment compounds have anthocyanidin-like structures with peltogyne skeleton.\u003c/p\u003e","manuscriptTitle":"Peltogynoids contributing to discoloration in Peltogyne mexicana heartwood","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-13 09:45:52","doi":"10.21203/rs.3.rs-4759481/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-10-06T11:55:06+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-08-29T03:01:50+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"29161256244065159621058050289650093160","date":"2024-08-11T12:07:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"36459870740864307103285734472629904983","date":"2024-08-08T11:21:55+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-08-06T11:30:46+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"11825220614149142623542562320534629204","date":"2024-07-30T11:22:14+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-07-30T08:19:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-07-23T11:52:17+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-07-19T06:34:21+00:00","index":"","fulltext":""},{"type":"submitted","content":"Wood Science and Technology","date":"2024-07-18T02:53:07+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"wood-science-and-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"wsat","sideBox":"Learn more about [Wood Science and Technology](http://link.springer.com/journal/226)","snPcode":"226","submissionUrl":"https://submission.nature.com/new-submission/226/3","title":"Wood Science and Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"8fbc5b35-58ee-4888-b6d1-d09df62f77c3","owner":[],"postedDate":"August 13th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-11-18T19:18:12+00:00","versionOfRecord":{"articleIdentity":"rs-4759481","link":"https://doi.org/10.1007/s00226-024-01617-3","journal":{"identity":"wood-science-and-technology","isVorOnly":false,"title":"Wood Science and Technology"},"publishedOn":"2024-11-15 15:58:15","publishedOnDateReadable":"November 15th, 2024"},"versionCreatedAt":"2024-08-13 09:45:52","video":"","vorDoi":"10.1007/s00226-024-01617-3","vorDoiUrl":"https://doi.org/10.1007/s00226-024-01617-3","workflowStages":[]},"version":"v1","identity":"rs-4759481","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4759481","identity":"rs-4759481","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}