Study Of The Chemical Constituents And Biological Activities Of Gentiana Crassicaulis Duthie Ex Burk.

Gentiana crassicaulis Duthie ex Burk.is a traditional Chinese medicine and Tibetan medicine with long history,which possesses anti-inflammatory and analgesic effects and usually be used in the treatment of arthritis and hepatitis.Up to now,the systematic research on Gentiana crassicaulis including chemical composition and biological activity is rarely reported.In this study,the n-butanol and chloroform extracts of the root of Gentiana crassicaulis were systematically separated by column and HPLC chromatography,and the structures of the isolates were identified by NMR(1D-NMR,2D-NMR),HR-ESI-MS and other spectral methods.A total of 20 compounds were identified,including two flavonoids:Kaempferol-7-O-β-D-glucopyranoside(1),Quercetin 4’-O-α-L-rhamnopyranoside(2);nine iridoids:Loganic acid(3),Loganin(4),Ketologanic acid(5),Swerimilegenin I(6),Swerimilegenin H(7),Swerimilegenin E(8),(-)-Swerimuslactone A(9),5-Hydroxymethylisochromen-1-one(10),6’-O-β-D-glucopyranosyl gentiopicroside(11);four phenolic acids:Ferulic acid(12),Linocaffein(13),Cyclic 4-O-β-D-glucopyranosylcaffeic acid dimer(14),Scrocaffeside B(15);one phenylethanoid:Phenethanol-β-vicianoside(16);two sterols:β-Sitosterol(17),β-Sitosterol-3-O-gentiobioside(18);one benzoic acid derivative:2-Hydroxyanofinic acid(19)and one oxazine:Lumichrome(20).In which,compounds 5,8,13,15 and 20 were firstly identified from the Genus of Gentiana.In order to explain the pharmacological activity of Gentiana crassicaulis,the antioxidant and anti-inflammatory effect of three phenolic acids isolated from Gentiana crassicaulis was evaluated.The experimental results showed that phenolic acids had a certain scavenging effect on DPPH radical,and compound 15 had an obvious antioxidant effect with a scavenging rate of 70.7%.The kinetics of DPPH radical scavenging reaction of compound 15 was studied,and it was found that the scavenging rate increased gradually with detection time expending,while the scavenging rate decreased gradually.MTT assay showed that these three compounds had no cytotoxicity.In the inflammatory model established using LPS as stimulus in RAW264.7 macrophage cells,three phenolic acid compounds(13,14,15)could inhibit NO production,among which compound 15 had the strongest effect.The study enriched the chemical composition of Gentiana crassicaulis and provided a theoretical basis for the quality control of Gentiana crassicaulis and the taxonomic study of Gentiana plants.