Bioactive secondary metabolites from marine Actinomyces sp. AW6 with an evaluation of ADME-related physicochemical properties

Abstract This study aimed to evaluate the antimicrobial, antioxidant, and cytotoxic potentials of crude extract of marine actinomycetes spp. isolated from the Red Sea water at Hurghada, Egypt. Out of 80 actinomycetes isolates, the isolate Actinomyces sp. AW6 was selected based on its antioxidant (IC50 about 5.24 µg/ml which scavenged 91% of formed DPPH free radicals) and antimicrobial potential against E. coli, S. aureus, B. subtilis, and P. aeruginosa, A. niger, and C. albicans. The strain was identified based on phenotypic and genotypic analysis and deposited in the GenBank with accession number OK090864. 1. Cultivation of the selected strain on rice, chromatographic purification, and structural elucidation led to the isolation of two compounds C1: umbelliferone and C2: 1-methoxy-3-methyl-8-hydroxy-anthraquinone. The antimicrobial activity of the obtained compounds showed that C1 and C2 have low antibacterial activity toward S. aureus and E. coli with no pronounced activity toward P. aeruginosa, C. albicans, and A. niger. Additionally, the antioxidant activity of C1 and C2 revealed that C2 has a good antioxidant activity, with DPPH scavenging activity reaching (55.25%), followed by C1 (30.20%). Moreover, both compounds displayed anti-Gyr-B enzyme activity with IC50 value of (3.79 ± 0.21 µM) for C1, and (IC50 = 13 ± 0.71µM) for C2. The ADME-related physicochemical properties of the obtained compound were predicted using SwissADME web tools and the ProToxii webserver was used to estimate in silico toxicity.