The Quality Standard And Evaluation Study Of Rhubarb From Rheum Emodi Wall.

Rhubarb from Rheum emodi Wall. is a traditional medicinal material used in folk, mainly distributed over Tibet, Qing hai, Si chuan, Yun nan provinces, et al, still cultivateed in some areas of Tibet in recent years. Its radix and rhizome is called Quza in Tibetan medicine, used in Tibet as hemostatic, anti-infl-ammatory, consolidant, promoter of gastric, et al. It is also used as official rhubarbs when they are not supplied enough. In recent years it has been discovered that it can be used as antidiabetic and in lipid accommodation.In order to exploit the rich resource of Rheum emodi Wall., the following studies were carried out:In this paper, the pharmacognostical study on Rheum emodi Wall. is reported, including external structures and morphological characters.The chemical constituents in rhubarb rhizomes and roots derived from Rhem emodi Wall. were approached. Eleven compounds were isolated and the structures were identified by chemical and spectroscopic methods as chrysophanol (Ⅰ) , physcion (Ⅱ),emodin (Ⅲ),β-sitosterol (Ⅳ),piceatannoI (Ⅴ),d-catechin (Ⅵ),daucosterol (Ⅶ),piceatannol-4′-O-β-D-glucopyranoside (Ⅷ),piceatannol-4′-O-β-D- (6″-O-galloyl) -gluco-pyranoside (Ⅸ),emodin-8-O-β-D-glucopyranoside (Ⅹ),chrysophanol-8-O-β-D-glucopyranoside (Ⅺ) .Ⅸwas obtained from this plant for the first time. In this paper, total anthraquinones and free anthraquinones of Rheum emodi Wall. were determined by UV spectrophotometry.An RP-HPLC assay is developed for determining stilbenes of piceatannol-4′-O-β-D-glucopyranoside and piceatannol in Rheum emodi Wall. The mobile phase was acetonitrile-water(16∶84) and (25∶75). The flow rate was 1.0 ml·min^-1. A UV detector at 320nm/325nm was used. The method was sensitive and specific. It was suitable for analysis of stilbenes in Rheum emodi Wall.