Further constituents from Caralluma negevensis

Two mew megastigmane glycosides (1 and 2) and two new flavone glycosides (3 and 4) were isolated from the methanol extract of the whole plant of Carallutna negevensis Zohary (Asclepiadaceae). The structures of the isolated compounds were characterized as (9R)-2beta,9-dihydroxymegastigma-4,7-dien-3-one-9-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (1), 2beta,9-dihydroxymegastigma-4-en-3-one 9-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranoside (2), luteolin 3'-O-beta-D-glucopyranoside-4'-O-alpha-L-rhamnopyranosyl-(1-->2)- P-D -glucopyranoside (3), and luteolin 3',4-di-O-beta-D-glucopyranoside (4). The structures of the isolated compounds were established on the basis of spectral evidence and chemical transformation. (C) 2003 Elsevier Science Ltd. All rights reserved.