Triterpenoids and triterpenoid saponins from Vitex negundo and their anti-inflammatory activities

Abstract

Seven undescribed polyoxygenated ursane-type triterpenoids (vitnegundins A-G), three undescribed triterpenoid saponins (vitnegundins H-J), and 17 known ones were isolated from an EtOH extract of the aerial parts of Vitex negundo L. The structures of the undescribed compounds were established by extensive spectroscopic analysis. The absolute configurations of vitnegundins A, B, and E were determined by single-crystal X-ray diffraction data. Vitnegundins B-D are pentacyclic triterpenoids possessing rare cis-fused C/D rings and vitnegundins C-H represent undescribed ursane-type triterpenoids with 12,19-epoxy moiety. In the biological activity assay, vitnegundin A, vitnegundin E, and swinhoeic acid displayed inhibitory effects against LPS-induced NO release in BV-2 microglial cells, with IC₅₀ values of 11.8, 44.2, and 19.6 μM, respectively.

Keywords: Anti-inflammatory; Triterpenoid saponin; Ursane-type triterpenoid; Verbenaceae; Vitex negundo L.; Vitnegundin.