Lycodine-Type Lycopodium Alkaloids from the Whole Plants of Huperzia serrata

Abstract

Abstract Three new lycodine-type Lycopodium alkaloids, namely 1-methyllycodine (1), 8α-hydroxy-15,16-dehydro-des-N-methyl-α-obscurine (2), N-methyl-16-hydroxyhuperzine B (3), and one new natural lycodine-type Lycopodium alkaloid, N-methylhuperzine A (4), along with 11 known analogues (5–15), were isolated from the whole plants of club moss Huperzia serrata. The structures of 1–4 were elucidated on the basis of NMR spectroscopic and mass spectrometry data. Among them, compound 1 was the first lycodine-type alkaloid possessing a methyl group at C-1. In addition, the structure of 5 was confirmed by the single-crystal X-ray crystallography data and its 13C NMR was reported for the first time in current study. Compounds 1–5 were tested their BACE1 inhibitory activity. Graphical Abstract

Keywords

• Lycopodium alkaloids
• Lycodine-type
• Huperzia serrata
• BACE1 inhibitory activity