Study On The Chemical Constituents And Bioactivity Of The Aerial Parts Of Ligularia Rumicifolia

Ligulari rumicifolia is the unique plant resources in Tibet,which also has a potential hazard to livestock health.At present,the research on L.rumicifolia mainly focus on nutrient content and components of alkaloids at home and aboard.For the system analysis of its chemical compounds and activity is still blank.In this study,we research the chemical conpounds,antibacterial activity and cytotoxicity of the aerial parts of L.rumicifolia and reveal its compounds and the main toxic components.Not only enriching the compounds of Ligularia sp.,also to lay the foundation for its toxicology.Well,giving the advice to prevent,control and develop L.rumicifolia comprehensively.1.Research on chemical conpounds systemly.Column chromatography（CC）,thin layer chromatography（TLC）are used for isolation,and NMR,GC-MS spectra are used for identific ation of the structures.There are 5 compounds were isolated,among which（3S,10R,13S,17R）-17-（（2S）-5-ethyl-3-hydroxy-6-methylheptan-2-yl）-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol、（10R,13R）-17-（（E）-5-ethyl-6-methylhept-3-en-2-yl）-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol、（3S,10R,13R,17R）-17-（（2S）-5-ethyl-3-hydroxy-6-methylhe ptan-2-yl）-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthrene-3,7-diol and 17-（5,6-dimethylhept-6-en-2-yl）-10,13-dimethyl-2,3,4,7,8,9,10,13,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol are sterols and（1R,8S,8a R）-8,8a-dimethyl-6-oxo-2-（propan-2-ylidene）-1,2,3,4,6,7,8,8a-octahydronaphthalen-1-yl（E）-2-m ethylbut-2-enoate is sesquiterpene.2 Analysed PE 1 by GC-MS.Using column chromatography to analyze petroleum ether extraction and eluting by petroleum ether.We collected the low polar region which is tested b y GC-MS.There are 55 compounds are identified,in which the major types are esters（23.86%）,alkane（23.76%）,olefin（3.65%）and sesquiterpene（2.88%）;the major components are:Pe ntacosane（16.89%）,Farnesyl acetate（8.32%）and（24R,25S）-Aply steryl acetate（7.82%）.3.Specific separation of alkaloid compounds:this study adopted systemic extraction foralkaloid,which takes 9 g alkaline dichloroform and 83.33 g alkaline n-butyl alcohol from 20kg the aerial parts of L.rumicifolia and the contents of them is 0.045%and 0.417%respectivel y.Using NMR spectra to identified the structures,there are 2 compounds were isolated,there are Senecioninea and（E）-3-（3-hydroxy-4-methoxyphenyl）-1-（2-hydroxy-5-methylphenyl）pro p-2-en-1-one.4.Biological activity detection.We used MTT to test the antibacterial activity by PE1and found the MIC₅₀value is 1.724 mg/m L,95%confidence interval is 1.072-2.827 mg/m L.It is shown that PE 1 has good antibacterial activity.In addition,The cytotoxicity of the extracts from the aerial parts of L.rumicifolia from strong to weak is:alkaline dichloromethane fragment,petroleum ether fragment,alkaline n-butyl alcohol fragment,dichloromethane fragment and n-butyl alcohol.And compound 2 and compound 6 have valid inhibition for BRL-3A.It is shown that alkaline dichloromethane fragment and petroleum ether fragment is the main antibacterial activity part.