Antioxidant and Cytotoxic Flavonols from Calotropis procera

Abstract

3 Phytochemical investigations of Calotropis procera leaves have led to the isolation of two new compounds: quercetagetin-6-methyl ether 3-O-β-D-4C1-galacturonopyranoside () and (E)-3-(4-methoxyphenyl-2-O-β-D-4C1-glucopyranoside)-methyl propenoate (4), along with eleven known metabolites: nine flavonol and two cinnamic acid derivatives. All metabolites were isolated for the first time from the genus Calotropis, except for 1 isolated previously from Calotropis gigantea. The structures were determined by spectroscopic methods (UV, ESI-MS, 1H, 13C NMR, 1H-1H COSY, HSQC, and HMBC). The radical scavenging activity of the aqueous methanol extract and compounds 8 - 13 was measured by the 1,1-diphenyl- 2-picrylhydrazyl (DPPH) method. Cytotoxic screening of the same compounds was carried out on brine shrimps as well