Benzopyran derivatives from the aerial parts of Eriostemon rhomboideus

Twelve compounds have been isolated from the aerial parts of Eriostemon rho mboideus, six of which are novel. The novel compounds have been characteris ed as the flavones, 3,5,7,8,3 ',4'-hexahydroxyflavone-3-O-beta-glucopyranos ide-7-methyl ether and 3,5,7,8,3 ',4',-hexahydroxyflavone-3-O-(6-p-coumaroy l)-beta-glucopyranoside-7-methyl ether, the 2-alkylbenzopyrans, 5,7-dihydro xy-2-heptacosanylbenzopyran-4- one and 2 xi, 5,7-trihydroxy-2-heptacosanyl- 2,3-dihydrobenzopyran-4-one, glyceryl-1-tetracosanoate and the coumarin, is obaisseoside-3'-p-coumarate (esculetin-7-O-(3-p-coumaroyl-6-alpha-rhamnopyr anosyl)-beta-glucopyranoside). The known compounds were eriostoic acid, eri ostemoic acid, hesperidin, sitosterol-3-O-beta-glucopyranoside and a mixtur e of catechin and epicatechin. The chemotaxonomic importance of the isolati on of a coumarin glycoside is noted. (C) 1999 Elsevier Science Ltd. All rig hts reserved.