Terpenes and flavonoids from an Egyptian collection of Cleome droserifolia

Four new sesquiterpene derivatives have been isolated from the aerial parts of Cleome droserifolia. Their structures were established as 6-di(7-hydroxy, 1, 5-epoxy germacrane) (2), 4(15)-guaiane-6-ol (3), 7-germacra-1(10), 4(15)-diene-5, 6-diol (4) and 4,7,8-eudesma-triol (5). In addition, a new dolabellane diterpene derivative with the naturally rare peroxy function was identified as methyl ester of 2,18-O-diacetyl-16-O-(3-hydroxy-3-methylglutaryl)- 7-hydroperoxydolabella-3,8(17)diene-2,16,18 triol (7). Two known flavonoid derivatives, pinocembrin (6) and quercetin-3-glucoside,7-rhamnoside (1) were isolated from the same source. Structures were established by spectroscopic data.