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 ( 1 H and 13 C NMR, 1 H −  1 H 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 IC 50 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.