Abstract: Aim To study the chemical constituents of seeds of Herpetospermum caudigerum. Methods Column chromatography was used in the isolation procedure, and the structure was elucidated by spectral data, whose pharmacologic activity was assayed in vitro. Results A new compound named herpetin was isolated, whose structure was determined to be 3-benzofuran methanol-2,3-dihydro-2-(4-hydroxy-3-methoxyphenyl)-4-methoxy-6-[tetrahydro-2-(3-hydroxy-4-methoxyphenyl)-3-methanol]-2-furanmethyl, showed significant inhibitory effects on HBV-DNA and the replication and expression of HBsAg and HBeAg. Conclusion Herpetin offers wide research and development prospect.

Key words: Herpetospermum caudigerum, Herpetospermum caudigerum, Lignan, Lignan, Herpetin, Herpetin, HBV, HBV, 2.2.15 cell line, 2.2.15 cell line