Triterpenoids from Ganoderma angustisporum and their α -glucosidase inhibitory activities

A novel triterpenoid, (22S, 24E)-3β, 15, 22-triacetoxy-6-oxolanosta-9, 24-dien-26-oic acid (1), together with eight previously identified analogues, was isolated from the solid-substrate culture of Ganoderma angustisporum J.H. Xing, B.K. Cui & Y.C. Dai. Their chemical structures were elucidated based on a comprehensive set of spectroscopic techniques, including 1D and 2D NMR as well as HRESIMS data. All obtained compounds were screened for α-glucosidase inhibitory activity. Compound 2 demonstrated potent inhibition (IC₅₀ = 18.26 ± 2.36 μM), exhibiting comparable activity to the positive control acarbose (IC₅₀ = 15.24 ± 2.63 μM). Molecular docking showed that compound 2 binds to the hydrophobic pocket of α-glucosidase by forming hydrogen bonds with Arg359, stabilising the complex with a binding energy of -7.2 kcal/mol.