Abstract
Three new metabolites, 5-hydroxy-3,7-dimethoxyflavone-4'-O-beta-glucopyranoside (1), 2 beta,19-epoxy-3 beta,14 beta-dihydroxy-19-methoxy-5 alpha-card-20(22)-enolide (4) and beta-anhydroepidigitoxigenin-3 beta-O-glucopyranoside (5), along with two known compounds, uzarigenine (2) and beta-anhydroepidigitoxigenin (3), were isolated from Calotropis procera (Asclepiadaceae). The structure elucidation was accomplished mainly by nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric methods. To examine putative antimicrobial or cytotoxic activities, various bioassays were performed. Uzarigenine (2) demonstrated moderate cytotoxicity. (C) 2010 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.