Cycloartane-Type Triterpenes from the Leaves of Homonoia riparia with VEGF-Induced Angiogenesis Inhibitory Activity

Abstract

Six new cycloartane-type triterpenes (1-6), 24-methylenecydoartane-3 beta,6 beta,7 beta-triol (1), 24-methylenecycloartane-3 beta,6 beta,7 beta,16 beta-tetraol (2), 24-methylenecycloartane-3 beta,6 beta,16 beta-triol (3), 24-methylenecycloartane-3 beta,7 beta,16 beta-triol 3-O-beta-D-xylopyranoside (4), 24-methylenecycloartane-3 beta,6 beta,16 beta-triol 3-O-beta-D-xylopyranoside (5), and 24-methylenecycloartane-3 beta,6 beta,7 beta-triol 3-O-beta-D-xylopyranoside (6), were isolated from the leaves of Homonoia riparia, together with one known compound, 24-methylenecycloartarie-3 beta,6 beta,7 beta,16 beta-tetraol 3-O-beta-D-xylopyranoside (7). The structures of the new triterpenes were established by spectroscopic studies and from chemical evidence, and the inhibitory effects of compounds 1 and 3-7 on VEGF-induced vascular permeability were examined in vivo in rats using the Miles assay. In addition, the inhibitory effect of 7 on VEGF-induced tube formation by HUVECs in vitro was investigated.