Structure Related α-Glucosidase Inhibitory Activity and Molecular Docking Analyses of Phenolic Compounds From Paeonia Suffruticosa

Abstract In the continuous search for α-glucosidase inhibitors, eleven phenolic compounds (1-11) were isolated from the root bark of Paeonia suffruticosa. Their α-glucosidase inhibitory activity and inhibition mechanism were investigated using an in vitro inhibition assay and molecular docking studies. Compounds 2, 5, 6, and 8-11 (IC50 between 290 and 431 µM) inhibited α-glucosidase more effectively than the reference compound acarbose (IC50=1463 ± 29.5 µM). Among them, compound 10 exhibited the highest α-glucosidase inhibitory effect with an IC50 value of 290.4 ± 9.6 µM. Compounds 2, 5, 9 10 and 11 were found to be competitive inhibitors, while compounds 6 and 8 were noncompetitive inhibitors of α-glucosidase. Computational analyses showed that the main binding forces between the compounds and the main residues were hydrogen bonds. The results indicated that these compounds had considerable α-glucosidase inhibitory activity.