Study On The Chemical Constitutions Of The Ethyl Acetate Extract From Swertia Mussotii

Swertia mussotii Franch is a medicinal plant of Swertia which comes from Gentianaceae and also is a well-known Tibetan medicine for the treatment of hepatitis and cholecystitis in Tibet of China.It locates in slopes,shrubs,forest margins and river banks at an altitude of 3600-3800 m.At present,the chemical constitutions of Swertia mussotii which were reported at home and abroad have five major components includes xanthones,triterpenoids,flavonoids,alkaloids and iridoids.Previous investigation reported that the ethanol extracts of Swertia mussotii and some compounds from it had showed a significant inhibition activity against HBV,but other activity had been demonstrated seldomly.In order to enrich the types and quantities of the chemical composition and find other active constituents from Swertia mussotii,this paper study on the chemical constitutions of the ethyl acetate extract,and the biological activity of some compounds from Swertia mussotii,which provides a preliminary reference for further study of biological experiment.The whole dried herbs of Swertia mussotii was crushed,and the chemical composition was extracted with 95%ethanol.Then collecting eluate and evapora ting solvent.After the concentrated solution dispersed into water,petroleum ether,ethyl acetate and butanol were added in order to obtain different fractions by e xtracting with them.1058g extraction was produced from the ethyl acetate extra ct,and the chemical constituents were separated and purified by using a combin ation of various chromatographic techniques including Sephadex LH-20,semi-pre parative column chromatography,Silica gel column chromatography,Reverse-pha se silica gel column chromatography,and recrystallization.Their structures were elucidated by physical and chemical properties,Thin-Layer Chromatography?T LC?,spectrum analysis like HR-ESI-MS,¹H NMR,¹³C NMR and so on.Finally,we identified 17 compounds,including 6 xanthones?compounds 1-6?,3 flavon oids?compounds 7-9?,2 iridoids?compounds 10-11?,2 phenols?compounds 12-13?,1 triterpenoid?compound 14?,and 3 steroids?compounds 15-17?.They wer e named as:1,5,8-Trihydroxy-3-methoxyxanthone?1?;1,7-Dihydroxy-3,8-dimethox yxanthone?2?;1-Hydroxy-3,5,8-trimethoxyxanthone?3?;1-Hydroxy-3,7,8-trimetho xyxanthone?4?;4,6,8-Trihydroxy-1,2,3,5-tetramethoxyxanthone?5?;Mangiferin?6?;Luteolin?7?;Isoorientin?8?;Isovitexin?9?;Swertiamarin?10?;Gentiopicroside?11?;Protocatechuic acid?12?;Vanillic acid?13?;Oleanolic acid?14?;?-Sitoster ol?15?;Stigmasterol?16?;?-Daucosterol?17?.Among the other compounds,co mpound 5 was isolated from the Gentianaceae plant for the first time,and com pounds 7,9,12,13 were isolated from Swertia mussotii for the first time.In addition,cytotoxic activity of some compounds was tested by three cancer cell lines,the B16,C6 and HepG 2.The result of the biological activity of some compounds shows that compound 5 have a significant inhibiting effect against C6cancer cell line,and the IC₅₀ values was 8.9?M.