Studies On The Chemical Constituents Of Lagotis Brevituba

This article is about studies on the chemical constituents of Lagotis brevituba,which is used as a Tibetan folk medicine,honglian.The studies lay foundation for further research in the active mechanism of anti-cancer and other pharmacological effects of the title plant.The ethanolic extract of Lagotis brevituba was isolated by L-L extraction,repeating column chromatography on silica gel and polyamide,preparative TLC on silica gel,semi-preparative RP-HPLC on C₁₈ silical gel and other methods.Ten compounds were obtained from petroleum ether soluble fraction and ethyl acetate soluble fraction.On the basis of analysis of the physico-chemical properties and spectra(FT-IR,¹H-NMR,¹³C-NMR,¹H-¹H COSY, HSQC,HMBC and MS) of these compounds,chemical structures of these ten compounds were elucidated,in which five are flavonoids and two are phenylethanoid glucosides.The ten compounds were identified as follows:succinic acid(1),apigenin(2),chrysoeriol(3), chrysoeriol-7-O-β-D-glucoside(4),luteolin-7-O-β-D-glucoside(5),apigenin-7-O-β-Dglucoside (6),uracil(7),[2-(3,4-dihydroxyphenylethyl)]-3-O-β-D-(4-methoxy)-xylopyranosyl-(1-3)-(4-O-caffeoyl)-β-D-glucopyranoside (8),acteoside(9),andβ-Sitosterol(10). Compound 8 was reported for the first time and was named as lagotiside.Apigenin-7-O-β-D-glucoside,chrysoeriol-7-O-β-D-glucoside,and uracil were isolated from the genus of Lagotis for the frist time;apigenin and chrysoeriol were isolated from L.brevituba for the frist time.