Further constituents from Caralluma negevensis

Abstract

Two new megastigmane glycosides ( 1 and 2) and two new flavone glycosides ( 3 and 4) were isolated from the methanol extract of the whole plant of Caralluma negevensis Zohary (Asclepiadaceae). The structures of the isolated compounds were characterized as (9 R)-2β,9-dihydroxymegastigma-4,7-dien-3-one-9- O-α- l-rhamnopyranosyl-(1→6)-β- d-glucopyranoside ( 1), 2β,9-dihydroxymegastigma-4-en-3-one 9- O-α- l-rhamnopyranosyl-(1→6)-β- d-glucopyranoside ( 2), luteolin 3′- O-β- d-glucopyranoside-4′- O-α- l-rhamnopyranosyl-(1→2)-β- d-glucopyranoside ( 3), and luteolin 3′,4′-di- O-β- d-glucopyranoside ( 4). The structures of the isolated compounds were established on the basis of spectral evidence and chemical transformation.