SERRATANE TRITERPENOIDS AND CAFFEIC ACID DERIVATIVES FROM WHOLE PLANTS OF LYCOPODIUM CLAVATUM AND THEIR POTENTIAL DPPH AND ACETYLCHOLINESTERASE INHIBITORY ACTIVITIES

Lycopodium clavatum is used in traditional medicine to treat conditions such as rheumatism, digestive disorders, and skin diseases. As part of our ongoing research on bioactive compounds from Vietnamese medicinal plants, phytochemical investigations of whole plants led to the isolation of five compounds (1–5). Using advanced analytical techniques, including electrospray ionization mass spectrometry (ESI-MS) and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy, the structures of these compounds were successfully elucidated as 21-epi-serratenediol (1), serratenediol (2), tohogenol (3), methyl ferulate (4), and methyl p-coumarate (5). The in vitro acetylcholinesterase (AChE) inhibitory activities of these compounds were evaluated, revealing that compound 3 exhibited an IC50 value of 8.3 ± 0.6 μM, which is comparable to that of the positive control, tacrine (IC50 = 2.5 ± 0.2 μM). Additionally, compounds 4 and 5 exhibited potent antioxidant activity in the DPPH assay, comparable to those of L-ascorbic acid (vitamin C). The results suggest that triterpenoids from L. clavatum are responsible for the AChE inhibitory activities, while caffeic acid derivatives contribute to the antioxidant activity. This study represents the first investigation into the chemical constituents, antioxidant properties, and AChE inhibitory effects of L. clavatum collected in Vietnam.