Study On The Chemical Constituents Of Two Yunnan Medicinal Plants

The thesis deals mainly with the chemical investigations of two Yunnan medicinal plants,Gochnatia decora and Cynanchum saccatum.A total of 48 compounds were isolated and identified from the above two kinds of plants through a variety of chromatographic separation techniques and spectroscopic analysis,which main structural types included ent-kaurane diterpene glycosides and C21 steroidal saponins,of which 31 were new compounds.11 compounds were identified from the n-butanol fraction of Gochnatia decora,mainly diterpenoid glycosides,of which 8 were new compounds.37 C21 steroidal glycosides,including 23 new were isolated and identified from the ethyl acetate fraction of Cynanchum saccatum.All isolated compounds were tested their neuroprotective effects on the model of H2O2-induced damage to PC 12 cells.Except saccatols D-F,J,cynsaccatol V and wilfoside A,other twenty-three isolates produced significantly activities against H2O2-induced cell damage(P<0.001).Furthermore,compounds 9,14,15 and 19 can obvious inhibition of damaged PC12 cell apoptosis at their dosages of 1 ?M by Annexin V-FITC/PI double staining assay with flow cytometry.