Diverse meroterpenoids with α-glucosidase inhibitory activity from Ganoderma cochlear

Three new meroterpenoids, cochlearins J–L (1–3) and three known meroterpenoids (4–6) were isolated from the fruiting bodies of Ganoderma cochlear. NMR (1H and 13C NMR, 1H − 1H COSY, HSQC, HMBC and ROESY), and HRESIMS were employed for the structure elucidation of new compounds. The stereostructures of 1–3 were confirmed by calculated ECD and optical rotation methods. Furthermore, compounds (+)-1, (−)-1, (+)-2, (−)-2, (+)-3, (−)-3, and 4–6 were evaluated for their α-glucosidase inhibitory activity. The results showed that compounds (+)-1, (−)-1 and (+)-2 exhibited stronger inhibition against α-glucosidase with IC50 values of 24.18 ± 1.98, 26.49 ± 3.20 and 29.68 ± 2.73 μM, respectively, compared to the positive control ursolic acid (49.65 ± 2.21 μM). The molecular docking experiments reveal that (+)-2 and (−)-2 had different binding mode with α-glucosidase, leading to their different inhibition.