Studies On The Secondary Metabolites And Bioactivities Of Five Medicinal Plants In Euphorbiaceae

Euphorbiaceae is a large family of angiosperms with 300 genera and around 8000 species.This family widely distributed in the world,mainly in tropical and subtropical regions.More than 864 species are widely distributed in southeastern to Taiwan of China.Euphorbiaceae includes 4 subfamily,Phyllanthoideae Ascherson,Euphorbioideae,Acalyphoideae Ascherson,Crotonoideae Pax.Euphorbiaceae is important economic plants,with rubber,oil,herbs,melted material,starch,mood et al.Hevea Aubl.is the main rubber plant,and castor is an important medicinal plants.Croton can be uesd as a laxative and pesticide,and also produces tannins.Most species of Euphorbiaceae are poisonous.The chemical constituents and their bioactivities of Euphorbia antiquorum L.,Euphorbia prostrata Ait,Euphorbia thymifolia L.,Macaranga denticulata,and Phyllanthus emblica L.were studied in this thesis.From the above plants,163 compounds were obtained,including 89 diterpenes,26 triterpenes,17 sterols,15 flavoids and 16 other type of compounds.Among them 66 were identified to be new ones,and most of them were diterpenes including 24 cembane-type diterpenes,19 ingol-type diterpenes and 13 other type of diterpenes.The genus Euphorbia is the largest in the spurge family,comprising more than 2000 species.Some species of the genus have been used as medicinal plants for the treatment of skin diseases,gonorrhea,migraine,intestinal parasites,and as wart cures.Diterpenoids are the majority of the genus with many different core framworks such as jatrophanes,lathyranes,tiglianes,ingenanes,myrsinols,etc.E.antiquorum L.,E.prostrata Ait,and E.thymifolia L.are all medicinal plants,from them,68 compounds,17 compounds,and 15 compounds isolated,respectively,manily for the diterpenes and triterpenes.Furthermore the bioactivities of some diterpenes from E.antiquorum L.were studied.The results indicated that compounds 55 and 57 had anti-HIV acivities with EC50 values of 7.40±0.94μM and 3.58±0.31μM,respectively.For PTP1B inhibitory activity,compounds 12 and 58 had better inhibitory activities with the IC50 values of 12.1 and 12.5μM,respectively.In addition,compounds 13,25,and 38 exhibited remarkable inhibitions against mouse 11β-HSD1 with the IC50 values of 11.95,6.36,and 0.41μM,respectively.Some species of the genus Macaranga have been used as medicinal plants in tropics.An overview of the literature indicated that this genus was a rich source of prenylated flavonoids.The leaves and twigs of Macaranga deheiculata are used in folk medicine for the treatment of jaundice,eczema,and chest and hypochondrium pain in China.From M.Deheiculata,26 compounds were isolated,and 12 of them were new cembranoids.The cembrane-type diterpenes were isolated from genus Macaranga for the first time.Furthermore,some cembranoids displayed the inhibitory activity against 11β-HSD1.Phyllanthus plants have been reported to contain terpenes,alkaloids,lignans,flavonoids,and tannins,etc.P.emblica L.is an important medicinal plant.Its fruit,roots,leave and bark all have medicinal value.From P.emblica L.,37 compounds were isolated.Furthermore the cytotoxicity of the steroids from this genus were studied,which found that compounds 131,133,and 136 had selective cytotoxicity against tumor and non-tumor cell lines.The results would be a supplement for the research on bioactivity of chemical constituents in traditional Chinese medicine,helpful reference for pharmacology,chemotaxonomy and screening new medicines,and may benefit utilizing and developing the natural resources of our country.Finally,the chemical constituents and their activities of the species of the genus Phullanthus reported were reviewed in this thesis.