| This thesis elaborated the studies on the chemical constituents of two plants,Walsura yunnanensis from the genus Walsura(Meliaceace),and Melodinus cochinchinensis from the Melodinus(Apocynaceae).The chemical study have led to the isolation of 42 compounds,including nortriterpenoids,triterpenoids,steroids,indole alkaloids,coumarins,flavonoids,lignins,iridoid and so on by using a multitude of spectroscopic methods(NMR,MS)as well as various separation and purification techniques.A new cycloartane triterpenoid(1),and a new natural product(2)were obtained from Walsura yunnanensis.Chapter 1: The chemical study on Walsura yunnanensis collected from the Xishuangbanna,Yunnan Province of China,had led to the isolation of 23 compounds.Among them,compound 1 is a new cycloartane triterpenoid,and 2 is a new natural steroid.Compounds 3-5 are limonids,compounds 6-12 are pentacyclic triterpenes,and compounds 13-15 are coumarins.The rest are lignans,flavonoids,benzene,and so on.Chapter 2: The chemical study on Melodinus cochinchinensis collected from the Gaoligong Mountains,Yunnan Province of China,had led to the isolation of 19 compounds,including 13 indole alkaloids.Among them,compounds 24-31,33-34 are aspidospermidine alkaloids,compound 32 is a vincamine alkaloid,compound 35 is a vincadine alkaloid,and compound 36 is a quinine alkaloid.Other compounds 37-40 are pentacyclic triterpenes,compound 41 is a iridoid,and compound 42 is a simple cumarin.Chapter 3,reviewed the progress on the chemical constituents and biological activities of the genus Walsura in the past 20 years. |
