Lycopodium Alkaloids from Huperzia serrata and Their Anti‐acetylcholinesterase Activities

Abstract One new fawcettimine‐type alkaloid ( 1 ), one new miscellaneous‐type alkaloid ( 2 ), four new lycodine‐type alkaloids ( 3 – 6 ), and eight known ones ( 7 – 14 ) were isolated from the whole plants of Huperzia serrata . Their structures and absolute configurations were elucidated based on spectroscopic data, X‐ray diffraction, ECD calculation and Mosher's method. Compound 1 was a rare C 18 N 2 ‐type Lycopodium alkaloid, possessing serratinine skeleton with an amide side chain in C‐5. The absolute configuration of the 18‐OH of compounds 4 – 6 were first determined by Mosher's method. Moreover, compounds 1 – 14 were assayed anti‐acetylcholinesterase effect in vitro , and compound 7 showed significant anti‐acetylcholinesterase activity with an IC 50 value of 16.18±1.64 μM.