Two new chromones and a new flavone glycoside from Imperata cylindrica

AIM:To study the chemical constituents of the rhizomes of Imperata cylindrica.METHODS:The compounds were isolated by silica gel and Sephadex LH-20 column chromatography.Their structures were elucidated mainly by spectroscopic analyses including IR,HR-ESI-MS,1D-and 2D-NMR.RESULTS:Two new chromones,8-hydroxy-2-(2-phenylethyl) chromone(1) and 2-(2-phenylethyl) chromone-8-O--D-glucopyranoside(2),and a new flavone glycoside,4'-methoxyflavone-6-O--D-glucopyranoside(5),along with five known compounds,flidersiachromone(3),5-hydroxy-2-(2-phenylethyl) chromone(4),flavone(6),4'-hydroxy-5-methoxyflavone(7) and 5-hydroxyflavone(8) were isolated from Imperata cylindrica.CONCLUSION:Compounds 1,2 and 5 were new compounds.