Study On The Chemical Constituents And Biological Activity Of Burma Simao Vine Leaves

The paper reviewed the research progress of androstane type compounds and related derivatives come from natural products or synthetic materials based on the previous reported literatures.We carried out the work around isolation and structure identification of chemical compositions from Epigynum cochinchinensis,especially for steroids.Subsequently,the immunosuppressuve and anti-inflammatory activity of the isolated steroids were evaluated.At the end of thesis,we concluded all the theories and practices in research process.The genus Epigynum,belonging to Apocynaceaeare,are widely distributed in forest margins of Thailand,Vietnam,Burma,Laos and Cambodia.Epigynum auritum in Yunnan Province is the only one species of genus Epigynum plants in China.Epigynum cochinchinensis as experiment materials was collected from forest margins of Laos.In our search for natural products with bioactivities,investigation of the EtOAc-soluble fraction from the leaves of Epigynum cochinchinensis led to the isolation of two new pregnane glycosides,epigycoside B(1)and epigycoside C(2),along with 14 known compounds(3-16).The structure of new compounds was elucidated by means of spectroscopic techniques,including HRMS,1D and 2D NMR experiments,combined with the results of acidic hydrolysis.The known compoimds were identified by comparisons of spectral data in reported literatures.Finally,16 compounds including pregnane glycosides(1-11),androstanes(12-14),triterpenoid saponin(15)and phenolic substance(16)were obtained and identified as epigycoside B(1),epigycoside C(2),periplocoside L(3),epigynoside L(4),epigynoside G(5),?5-Pregnene-3?,17?,20S-triol(6),epigynoside E(7),epigynoside F(8),epigynoside H(9),epigynoside A(10),epigynoside C(11),androst-4,6,8(9),13(14)-tetraene-3,11,16-trione(12),3-O-methyl-androsta-3?,12?-triol-4,14-diene-16-trione(13),3-O-ethyl-androsta-3?,12?-triol-4,14-diene-16-trione(14),3?-hydroxyoleane-6?-oxethyl-12-en-28-oic acid 3-O-?-D-glucuronic acid(15),3,5-Dimethoxy-4-hydroxybenzaldehyde(16).Immunosuppressive activity of compounds 1-14 was evaluated by CCK-8 assay to test the inhibitory activity against T/B-lymphocytes,while anti-inflammatory activity was evaluated by ELISA assay to detect te expression levels of TNF-?,IL-1? and PGE2 secreted from LPS-induced RAW264.7 cells.The result displayed that the steroids(1-14)we obtained from Epigynum cochinchinensis generally had immunosuppressive activity to some extend,especially at the concentration of 50 ?M.Meanwhile the pregnane glycoside,compound 1 and 5 also showed significant antiinflammatory activity.Acordding to above research work,we further realize the natural products in Epigynum cochinchinensis and the cognition of natural product resources is expanded.The work lays a foundation of theory and substance for related research and drug development.