Two New Compounds from the Roots of Rheum palmatum

AimTo study the constituents of Rheum palmatum.MethodsChromatographic separations of silica gel and polyamide were used. All the structures were elucidated on the basis of chemical and spectroscopic analysis.ResultsNine compounds were isolated and their structure were identified as 2, 5-dimethyl-6, 8-dihydroxy-chromone (1), 1-methyl-2, 8-dihydroxy- 3-carboxy −9, 10-anthraquinone (2), citreorosein (3), 4-(4-hydroxyphenyl)-2-butanone (4), 4-(4-hydroxyphenyl)-2-butanone-4′-O-β-D- (2″-galloyl-6″-O-p-coumaroyl)-glucopyranoside (5), trans-3, 5, 4′-trihydroxystilbene-4′-O-β-D-(6″-galloyl)-glucopyranoside (6), 4-(4- hydroxyphenyl)-2-butanone-4′-O-β-D-(6″-O-cinnamoyl)-glucopyranoside (7), 4-(4-hydroxyphenyl)-2-butanone-4′-O-β-D-(6″-O-p-coumaroyl)-glucopyranoside (8), trans-3, 5, 4′-trihydroxystilbene-4′-O-β-D-glucopyranoside (9).ConclusionCompounds 1 and 2 were newly isolated from Rheum palmatum.