Study On Chemical Constituents And Biological Activities Of Oreorchas Patens

Objective:The separation and identification of unknown monomer compounds in the traditional Chinese medicinal plant Oreorchas patens were reported in this work.Further,the antioxidant and antibacterial activities of the isolated compounds were evaluated in vitro,which provided theoretical basis for the deeper research of the development and utilization of traditional Chinese medicinal plant Oreorchas patens.Methods:Cold leaching method was used for extraction first.After that,extraction with petroleum ether,ethyl acetate and n-butanol respectively,then chromatographic methods such as gel column chromatography,silica gel column chromatography and?RP-18?reversed-phase column chromatography were adopted to isolation.Tracing and analysis of compounds were performed via thin-layer chromatography,and finally separation and purification of monomer compounds in Oreorchas patens were given mainly by recrystallization and other means.The structures of the compounds were established by means of nuclear magnetic resonance(¹H-NMR,¹³C-NMR,HMBC,HMQC)spectroscopy,mass spectrometry?MS?and data from relevant literature.DPPH radical scavenging method and MTT assay were used to detect the antioxidant and antibacterial activity of monomer compounds isolated from Oreorchas patens,respectively.Results:A total of 16 monomer compounds were isolated from the traditional Chinese medicine Oreorchas patens and 11 of them were identified,including steroids,tetracyclic triterpene,carboxylic acids,esters,aldehydes,flavonoids and glycosides.Among them,there are two kinds of steroid compounds:?-sitosterol?1?,and?-sitosterol-3-O-?-D-glucopyranoside?2?.There are one kind of tetracyclic triterpene compound:?24S?-24-methyl-25,32-cyclo-5?-lanosta-9?11?-en-3?-ol?3?.There are three kinds of carboxylic acid compounds and derivatives:hexadecanoic acid?4?,hexadecanoic acid,2,3-dihydroxypropyl ester?5?and 9-octadecenoic acid-2',3'-dihydric propylester?6?.There are two kinds of aldehyde compounds:vanillin?7?,and3-Hydroxy-4-methoxybenzaldehyde?8?.There are three kinds of flavonoids and flavonoid glycosides:quercetin?9?,isoquercitrin?quercetin-3-O-?-D-glucoside??10?and rutin(quercetin-3-O-?-D-glucopyranolsyl?1?4?-?-rhamopyranoside?11?.By analyzing the DPPH radical scavenging ability of six compounds,the order of their antioxidant activity is:vanillin>?-sitosterol>hexadecanoic acid>unknown?SL-a?>3-Hydroxy-4-methoxybenzaldehyde>?24S?-24-methyl-25,32-cyclo-5?-lanosta-9?11?-en-3?-ol.Among them,the IC₅₀ values of vanillin,?-sitosterol and hexadecanoic acid are 0.66mg/mL,0.67 mg/mL and 0.71 mg/mL respectively,which are stronger than other compounds.The antibacterial activity of six monomer compounds were tested by MTT assay.The results showed that compound hexadecanoic acid showed significant inhibitory effect on bacterial growth and contributed to the high growth inhibition rate on Escherichia coli,Bacillus subtilis,Staphylococcus aureus,Pseudomonas aeruginosa,Salmonella typhimurium and Vibrio parahaemolyticus.?-sitosterol and vanillin displayed obvious bacteriostasis as well.Conclusion:Eleven compounds,compounds 3-11 were isolated from the medicinal materials of Oreorchas patens for the first time and identified on the basis of NMR spectroscopy and HRESI-MS data.The structure identification and biological activity evaluation of compounds lay the foundation for revealing the pharmacodynamic substances of traditional efficacy of Oreorchas patens,and provide theoretical basis for further development and utilization of Oreorchas patens resources.Otherwise,the research results of biological activity are of great significance for promoting the industrial development of Oreorchas patens medicinal materials,and provide scientisic basis for further development and utilization of Oreorchas patens.