Fungal transformation of cedryl acetate and α-glucosidase inhibition assay, quantum mechanical calculations and molecular docking studies of its metabolites

The fungal transformation of cedryl acetate (1) was investigated for the first time by using Cunninghamella elegans. The metabolites obtained include, 10β-hydroxycedryl acetate (3), 2α, 10β-dihydroxycedryl acetate (4), 2α-hydroxy-10-oxocedryl acetate (5), 3α,10β-dihydroxycedryl acetate (6), 3α,10α-dihydroxycedryl acetate (7), 10β,14α-dihydroxy cedryl acetate (8), 3β,10β-cedr-8(15)-ene-3,10-diol (9), and 3α,8β,10β -dihydroxycedrol (10). Compounds 1, 2, and 4 showed α-glucosidase inhibitory activity, whereby 1 was more potent than the standard inhibitor, acarbose, against yeast α-glucosidase. Detailed docking studies were performed on all experimentally active compounds to study the molecular interaction and binding mode in the active site of the modeled yeast α-glucosidase and human intestinal maltase glucoamylase. All active ligands were found to have greater binding affinity with the yeast α-glucosidase as compared to that of human homolog, the intestinal maltase, by an average value of approximately −1.4  kcal/mol, however, no significant difference was observed in the case of pancreatic amylase.

Graphical abstractThis paper describes fungal transformation of cedryl acetate (1) and α-glucosidase inhibitory activity of the transformed products. Detailed docking studies of all metabolites were performed using Autodock.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Reporting seven new bio-transformed products by Cunninghamella elegans. ► Introducing new class of organic compounds as potent yeast a-glucosidase inhibitors. ► Rationalizing inhibitors’ activity at molecular level. ► Inhibitors optimization at QM level to eliminate possible error in docking study.