Isolation and Structure Elucidation of Uncommon Secondary Metabolites from Cistus salviifolius L.

To our knowledge this is the first report on the isolation of a flavonoid glycoside: quercetin 3-O-α-arabinopyranoside (5), two phenylbutanon glycosides: 4-(4'-O-[6''-O-galloyl-β-galactopyranosyl]-3'-hydroxyphenyl)-butan-2-on (8), 4-(3'-O-β-glucopyranosyl-4'-hydroxyphenyl)-butan-2-on (9), one phloroglucinol glycoside: 1-O-β-glucopyranosyl-3,5-dimethoxybenzene (10) and a steroid glycoside: sitosterol-3-O-(6''-O-butanoyl)-β-galactopyranoside (14) from the Cistus species (Cistaceae). Additional to these compounds three flavonol aglycones: kaempferol (1), quercetin (2), myricetin (3); three flavonoid glycosides; kaempferol 3-O-β-(6''-O-trans-p-coumaroyl)-glucopyranoside (4), quercetin 3-O-β-galactopyranoside (6), myricetin 3-O-β-galactopyranoside (7); one phloroglucinol glycoside: 1-O-β-glucopyranosyl-3,5-dimethoxybenzene (11); one steroid aglycone: β-sitosterol (12); one steroid glycoside: Sitosterol-3-O- β-glucopyranoside (13) were isolated from the aerial parts of the Cistus salviifolius L.. Their structures were identified using spectral methods (UV, IR, 1D- and 2D-NMR, and ESI-MS).