Chemical constituents of Rheum emodi / 中草药

ABSTRACT

Objective To isolate and determine the structures of chemical constituents from the roots and rootstalks of Rheum emodi.Methods The chemical constituents were isolated and purified by silica gel and polyamide column chromatography.Chemical methods and spectroscopic methods,such as 1H-NMR,13C-NMR,and MS spectra were used for the structure identification.Results Eighteen compounds were obtained.Sixteen of them were identified aschrysophanol(1),physcion(2),?-sitosterol(3),emodin(4),aloe-emodin(5),rheumin(6),daucosterol(7),d-catechin(8),piceatannol(9),piceatannol-4'-O-?-D-glucopyranoside(10),piceatannol-4'-O-?-D-(6″-O-p-coumaroyl)-glucopyranoside(11),chrysophanol-8-O-?-D-glucopyranoside(12),physcion-1 and 8-O-?-D-glucopyranoside(13a and 13b),emodin-8-O-?-D-glucopyranoside(14),and sucrose(15).Meanwhile,one compound structure simi-lar to rhein was detected.Conclusion Compound 11 is a new compound named rheoside,compounds 13a and 13b are obtained from R.emodi for the first time.