Glycosides of Verbascum letourneuxii, Asch. and its Antioxidant Activity

Five iridoid glycosides, 6-O-(a-L-rhamnopyranopranosyl)-catalpol, 6-O-(3"-O-acetyl-2"-O-p-methoxy cinnamoyl-a-L-rhamnopyranosyl) catalpol, 6-O-(3"-O-p-methoxycinnamoyl-a-L-rhamnopyranopyranosyl) aucubin, 6-O-syringoyl-ajugol and harpagoside have been isolated from the methanolic extract of Verbascum letourneuxii, beside isolation of two phenylethanoide glucoside, eukovoside, martynoside, two phenylpropanoid glucoside, syringin and coniferin, from the ethyl acetate extract. Meanwhile two neolignan glucosides, dehydrodiconferyl alcohol-9-O-P-D-glucopyranoside and 4-O-methyl-dehydrodiconiferylalcohol-9-O-P-D-glucopyranoside have been isolated from the butanol extract. These compounds were isolated, purified by column chromatography and PTLC then identified through UV, I.R., Mass, 13C and ʹH-NMR spectral data. The antioxidant activity of the plant extract using diphenylpicryl hydrazyl (DPPH) radical scavenging method showed that the butanol, ethyl acetate and methanol (80%) extracts posses antioxidant activity