Two Lycopodium Alkaloids from the Aerial Parts of Huperzia phlegmaria

Background: Huperzia phlegmaria has been used to enhancing memory and alleviate brain disorders. It contains high amount of alkaloids, which are potent acetylcholinesterase (AChE) inhibitor. Materials and Methods: Lycopodium alkaloids from aerial parts of H. phlegmaria were isolated by chromatographic methods. Their structures were elucidated by spectroscopic methods, including mass spectrometry and nuclear magnetic resonance. AChE inhibitory effect of isolated compounds in vitro was evaluated using Ellman’s assay. Results: These compounds were identified as fawcettidine and 12‑epilycodoline N‑oxide. Two compounds showed moderately AChE inhibitory effects with IC₅₀ values of 33.11 µg/mL and 64.56 µg/mL, respectively. Conclusion: These isolated compounds could be promising drugs for the treatment of Alzheimer’s disease.