Phenolic Compounds from Roots of Imperata cylindrica var. major

Objective To study the chemical constituents from the roots of Imperata cylindrica var. major. Methods The chemical constituents were isolated and purified by combination of silica gel, Sephadex LH-20, polyamide, and ODS column chromatography. The structures of the isolated compounds were identified by means of spectral data and physicochemical property. Results Twelve phenolic compounds were isolated from I. cylindrica var. major and identified as 4,7-dimethoxy-5-methylcoumarin (1), 7-hydroxy-4-methoxy-5-methylcoumarin (2), 7-O-beta-D-glucopyranosyl-4-methoxy-5-methylcoumarin (3), 6-hydroxy-5-methoxyflavone (4), 5-methoxyflavone (5), 5,7-dihydroxy-8-methoxyflavone (6), 4-hydroxybenzaldehyde (7), 4-hydroxy-cinnamic acid (8), 4-hydroxy-3-methoxybenzoic acid (9), 3,4-dimethoxyphenyl-O-a-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranoside (10), impecyloside (11), and graminone A (12). Conclusion Compounds 2-4, 6, and 10 are obtained from this plant for the first time.