Free Radical Scavenging Phenylethanoid Glycosides From Leucas Indica Linn.

A new phenylethanoid glycoside, 2-(3,4-dihydroxyphenyl)-ethyl-O-alpha-L-rhamnopyranosyl-(1 -> 3)-O-alpha-L-rhamnopyranosyl-(1 -> 6)-4-O-E-feruloyl-beta-D-glucopyranoside (3-O-methyl poliu-moside, 1) along with five known phenylethanoid glycosides (2-6) were isolated from the aerial parts of Leucas indica Linn. The structure of compound 1 has been elucidated on the basis of spectral data. Compounds 1-6 exhibited significant antioxidant activity in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay method. These compounds were also found to be moderate inhibitors of xanthine oxidase (XO) enzyme.