Three lycopodium alkaloid N-oxides, huperzine J (1), huperzine K (2) and hu
perzine L (3) were obtained from Huperzia serrate (Thunb.) Trev. Their stru
ctures were elucidated by spectroscopic methods and the relative configurat
ions of 1 and 3 were established via NOESY NMR observations; optical rotati
on values and CD data are presented.