Research On Chemical Constituents From Metaplexis Japonica Pericarp And Their Biological Activities

Metaplexis japonica(Thunb.)Makino.,also known as milkweed,is a perennial entwined vine of the genus Metaplexis,mainly distributed in Asia,and mainly distributed in northeast,north,northwest and southwest China.All parts of Metaplexis japonica(Thunb.)Makino can be used as medicine,which can cure fatigue,weakness,waist pain,cough,etc.Previous phytochemical research has led to the isolation of C21 steroids,terpenoids,flavonoids,lignans and other compounds.Phamarcological studies have proved that Metaplexis japonica(Thunb.)Makino.possesses anti-tumor,anti-inflammatory and immunotherapy,antioxidant and other activities.At present,there are many researches on the whole grass and roots of Metaplexis japonica(Thunb.)Makino.,but no other parts have been studied.Therefore,this article selects Metaplexis japonica Pericarp as the research object,and describes the isolation of petroleum ether,dichloromethane and ethyl acetate fractions from the concrete exacted by 95%EtOH.The C21 steroid and coumarin components were isolated from the samples,and their antitumor and antioxidant activities were studied.The whole article includes:Chapter 1.Literature researchThe relevant literature was summarized on the research progress about the chemical constituents and pharmacological effects of Metaplexis japonica(Thunb.)Makino.And on this basis,the research ideas and research content of this paper were formulated.Chapter 2.The research on chemical constituents of Metaplexis japonica PericarpThe petroleum ether,dichloromethane and ethyl acetate fractions of 95%ethanol extract from Metaplexis japonica Pericarp were isolated and purified by silica gel?Sephadex LH-20?MPLC and preparative HPLC,etc.The structures of the obtained compounds were identified by chemical methods,physical and chemical properties,and spectral data.A total of 20 compounds were isolated and identified as:?-sitosterol(1),25-hydroperoxycyc-loart-23-en-3?-ol(2),?-amyrin(3),scoparone(4),aleuritin(5),syringaresinol(6),Pergularin-3-O-?-D-oleanodropyranose(7),(15?,21?)-dihydroxypregna-17,20-trimethylene oxide-4,6-dien-3-one(8),(20?)-21-dihydroxypregna-4,6-dien-3-one(9),blumenol A(10),4-pregnen-20,21-diol-3-one(11),?-Adenosine(12),isoscopoletin-?-D-glucoside(magnolioside)(13),benzyl-O-?-D-glucopyranoside(14),tortoside A(15),icariside B1(16),(6S,9S)-raseoside(17),(6S,9R)-raseoside(18),salidroside(19),Stemmoside A(20).Among them,Compound 8 is a new C21 steroidal compound which was unreported,compounds 2,9,11,12,16,17,18,19 and 20 are isolated from the genus Metaplexis for the first time,and compounds 2,9,11,12,14,16,17,18,19 and 20 are isolated from this plant for the first time.Chapter 3.The in vitro study on anti-tumor activity of the compounds isolated from Metaplexis japonica PericarpThe antitumor cytotoxicity of 20 compounds isolated from Metaplexis japonica Pericarp was investigated by MTT experiments.The results showed that part of the compounds showed a certain degree of anti-tumor effect in vitro.Among them,the effect of compound 11 was better.Further research can be done to understand its mechanism accurately.Chapter 4.Study on antioxidant activity of the compounds and different parts of Metaplexis japonica PericarpThe antioxidant capacity and the ability to scavenge free radicals of 20 compounds,the petroleum ether,dichloromethane,ethyl and meyhanol acetate fractions of ethanol extracts isolated from Metaplexis japonica Pericarp were investigated by DPPH,ABTS+and FRAP kits.The results showed that parts of the 20 compounds and parts of polar extracts of Metaplexis japonica Pericarp have certain scavenging effects on the free radicals of the DPPH,ABTS+,and FRAP kits.