Isolation Of Liposoluble Components From Nepeta Bracteata Benth. And Its Anti-inflammatory Activity In Vitro

Nepeta bracteata Benth.is a Nepeta plant of the Lamiaceae family.The whole plant is used as medicine.It is mainly distributed in Pakistan,Nepal,Iran and other countries.It is a folk medicine used by Xinjiang Uyghurs,which has been included in"Uyghur Medicine History"（1986 edition）.Its qi is slightly fragrant,light in taste,and enters the lungs and liver meridian.It has strong activity in relieving cough,dispelling asthma,clearing heat and removing dampness,and is clinically used to treat symptoms such as tracheal inflammation,cough and asthma,cold and fever,and poor urination.The pharmacodynamic substances of N.Benth are mainly mainly terpenoids,including monoterpenoids and diterpenoids,and the anti-inflammatory and antibacterial activities of diterpenoids are better.In order to further understand the material basis of N.Benth,this study systematic separated dichloromethane and petroleum ether extract of N.Benth,which provides a basis for the further development of the medicinal value of N.Benth.The research’s main contents are as follows:1.The liposoluble components of N.Benth was respectively separated and purified by silica gel column chromatography,reversed-phase C₁₈ column chromatography and pre-parative HPLC,the structures were determined by spectroscopic methods and spectral technique.Forty-six compounds were isolated from N.Benth,contains six new compounds.They were identified as3-（4’-formylphenoxy）-4-methoxybenzaldehyde（1）,salicylis acid（2）,（E）-3-（4-hydroxyphenyl）acrylicacidethylester（3）,2,6,2’,6’-tetramethoxy-4,4’-bis（2,3-epoxy-1-hydroxypropyl）biphenyl（4）,5-hydroxymethylfurfural（5）,4’-（aminomethyl）-2,2’,6-trimethoxy-[1,1’-biphenyl]-4-carboxylicacid（6）,trans-3-hydroxy-4-methoxy-cinnamic acid（7）,pubinernoid A（8）,Coleolactone（9）,Ethyl3,4-dihydro-2-oxo-2H-pyrrole-5-carboxylate（10）,4-Hydroxy-3,5-dimethoxybenzaldehyde（11）,angustanoic acid F（12）,7a-hydroxycallitrisic acid（13）,1-Phenanthrenecarboxylicacid（14）,6-methyl-1,4-oxazocane-5,8-dione（15）,L-Pyroglutamic acid ethyl ester（16）,5,5’-dimethoxy xylenol A（17）,angustanoic acid G（18）,giadifenoic acid K（19）,4-hydroxybenzaldehyde（20）,Ficusic acid（21）,Propyl caffeate（22）,（+）-sesamin（23）,nepetabrate A（24）,Ferulic acid（25）,hydroxydihydrobovolide（26）,7-oxocallitrisic acid（27）,oleanolic acid（28）,nepetabrate B（29）,nepetabrate C（30）,1,2,3,4,4a,9,10,10a-octahydro-7-isopropyl-1,4a-dimethylphenanthren-1-yl)methanol（31）,1,2Benzenedicarboxylic acid（32）,lambertic acid（33）,20β-Hydroxyursolic acid（34）,1,2,3,4,4a,9,10,10a-octahydro-7-isopropyl-1,1,4a-trimethylphenanthrene-2,9-diol（35）,nepetabrate D（36）,triptobenzene L（37）,13S-hydroxy-9-oxo-9,10-seco-abiet-814)-en-18,10a-olide（38）,abieta-8,11,13-triene-7a,19-diol（39）,1-Phenanthrenemethanol（40）,1,7-Phenanthrenedimethanol（41）,9-Phenanthrenol（42）,1α-Phenanthrenecarboxylicacid（43）,1,2,3,4,4a,9,10,10a-octahydro-a⁷,a⁷,1,4a-tetramethyl-a¹-acetate（44）,7a-hydroxyabieta-8,11,13-trien-19-ylacetate（45）,1,2,3,4,4a,9,10,10a-octahydro-9-hydroxy-1,4-dimethyl-7-（1-methylethyl）-a-acetate （46）.Among them,compounds 6,15,24,29,30 and 36 are new compounds,and all compounds are isolated from N.Benth for the first time.2.Nineteen known diterpenes and six new compounds were isolated and tested for their anti-inflammatory activities by MTT assay in vitro.The LPS stimulated mouse macrophage RAW264.7 inflammation was used as the model,and the NO secretion was used as an index to study the anti-inflammatory activity of some diterpenoids.The results showed that among the diterpenoids,compounds 29 and 30showed strong anti-inflammatory activities with IC₅₀ values of 0.00235 and 0.00112mg/ml,respectively.In this experiment,the chemical constituents of Nepeta bracteata Benth.was systematically studied.N.Benth is rich in chemical components,and diterpenes were the main active components.The screening results of anti-inflammatory activity in vitro suggest that Nepeta bracteata Benth has the potential to develop new anti-inflammatory drugs.