Lycopodium Alkaloids from Huperzia serrata

Three new lycopodium alkaloids, huperserramines A–C (1–3, resp.), along with 15 known ones, lycopodine‐6α,11α‐diol (4), lycoposerramine H (5), lycoposerramine I (6), lycopodine‐6α‐ol (7), lycoposerramine M (8), diphaladine A (9), lycoposerramine K (10), lycoposerramine W (11), huperzine M (12), luciduline (13), phlegmariuine N (14), huperzine A (15), huperzine B (16), lycodine (17), and lycoposerramine R (18), were isolated from the whole plant of Huperzia serrata. Their structures were established by spectroscopic methods, including 2D‐NMR and MS analyses. All the isolates were evaluated for their inhibitory effects on acetylcholinesterase (AChE) and α‐glucosidase. As a result, lycopodine‐6α,11α‐diol (4) exhibited more potent α‐glucosidase inhibitory activity (IC50 148±5.5 μM) than the positive control acarbose (IC50 376.3±2.7 μM).