Chemical Constituents And Bioactivities Of Przewalskia Tangutica Maxim.

Przewalskia tangutica Maxim.（Solanaceae）,known as“Tang Chong Ga Bao”in Tibetan medicine,introduced as an Perennial herb,was recorded in the Chinese Pharmacopoeia 1977 Edition.It is a rare and endangered species unique to China,often used as Tibetan medicine,mainly distributed in Tibet and so on.It has anti-spasmodic,analgesic,and other pharmacological effect.It can treat unknown swelling and pain for external use,but it is toxic when taken orally.Previous investigations on the chemical constituents of this plant resulted in isolation of alkaloids,coumarins and flavonoids,and modern pharmacological studies have confirmed that it has anti-bacterial and anti-inflammatory.As a common medicinal material of Tibetans,P.tangutica has been reported in the literature with a low number and type of compounds.In order to further enrich the research materials of this plant,we selected the dried root of the P.tangutica as the research object,analysed its chemical composition,and the obtained compounds were evaluated for anti-tumor,anti-oxidant and anti-inflammatory activity in vitro.The roots of P.tangutica（50 kg）were extracted with 80%Et OH,and the extraction was repeated 3 times for 2 h each time.After evaporation of the solvent,the concentrated residue was suspened in water and partitioned with pertroleum ether,Et OAc and n-Bu OH successively.And then the three extraction parts were separated and purified systematically.In this study,30compounds were isolated from the 80%ethanol extract of the roots of P.tangutica by different chromatographic methods such as Sephadex LH-20,silica gel CC and the structures of 23 compounds were identified by their physical properties,MS and NMR spectrum.They were identified asα-amyrin（1）,betulinic acid（2）,betulin（3）,1,3-dihydroxyanthraquinone（4）,2-methylanthraquinone（5）,1-hydroxyanthraquinone（6）,1,3-dihydroxy-2-carboxyanthraquinone（7）,12-oleanol-3,11-dione（8）,ursolic acid（9）,heptacosan-1-ol（10）,n-pentacosane（11）,n-decanethiol（12）,inositol（13）,γ-valerolactone（14）,campesterol（15）,stigmasterol（16）,β-sitosterol（17）,β-carotene（18）,sucrose（19）,1,3-dimyristin（20）,p-hydroxybenzoic acid（21）,vanilla acid（22）,vanillin（23）.According to their structures,the compounds obtained from P.tangutica can be classified as 5 triterpenoids,4anthraquinones,4 steroids,2 phenolic acids and 8 other types,and compounds1～8,10～17,19～20,23 were isolated from this plant for the first time.In this study,A549,MCF-7,Hela and Hep G2 as tumor models,and the CCK-8 method was used for cytotoxicity evaluation in vitro.The results showed that compound 2 and compound 3 had significant cytostatic effects,and the IC₅₀values for most cell lines were all less than 20μM.In this study,the antioxidant activity of total extract,sub-site extracts and compounds from P.tangutica were evaluated in vitro by the ABTS method,and the results showed that compound 4 and compound 7 were 0.31±0.08 m M and 0.30±0.07 m M,the results showed that compound 4 and compound 7 had certain antioxidant activity.In this study,LPS-stimulated the murine macrophage cell line RAW264.7 as the cell model,the anti-inflammatory activity of total extract,sub-site extracts and compounds from P.tangutica were evaluated in vitro by the Griess method.The results showed that the total extract of P.tangutica,Et OAC extract and n-butanol extract had a certain inhibitory effect on NO release,which showed that P.tangutica have anti-inflammatory activity in vitro,Among them,the anti-inflammatory activity of the n-butanol extract is better.