|其他摘要||This dissertation elaborates the studies on the chemical constituents of the natural resources of three species, Rauvolfia vomitoria, Rauvolfia yunnanensis and Momordica charantia. From above three species, a total of 46 compounds, including 7 new compounds, were obtained. These compounds covered monoterpenoid indole alkaloids, cucrbitane-type triterpenoids, iridoids, steroids, and ceramides. Their structures were elucidated mostly on the basis of spectroscopic data.
Chapter 1. Studies on chemical constituents of Rauvolfia.
Monoterpenoid indole alkaloids with various structural types and huge amount, play a significant role in natural products family; the majority of monoterpenoid indole alkaloids have high biological activities, such as anti-hypertensive, anti-tumor, anti-malarial and others. To find more monoterpenoid indole alkaloid with novel structure and prepare for the development of Rauvolfia in Yunnan Province, two species of Rauvolfia, cultivated in Simao (R. vomitoria) and Xishuangbanna (R. yunnanensis), had been studied. From R. vomitoria, 15 compounds were isolated, and 1, 3, 4, 5, 6, 9, 15 were obtained for the first time in this genus; from R. yunnanensis, 12 compounds were separated and identified, and one of them is a new monoterpenoid indole alkaloid.
Chapter 2. Studies on Chemical constituents of Momordica charantia L.
M. charantia L, also called bitter gourd, as favorite edible medicine plants, is very popular in China. Its hypoglycemic activity is also a focus for the therapy of diabete; in order to explore the hypoglycemic active principles in the bitter gourd, the stems and leaves of M. charantia L had been investigated, and 19 compounds were obtained from the n-butanol extract. Compound 4, 13, 14, 16, 17, 18 were new cucurbitane- type triterpenoids, and compound 3 was obtained for the first time from natural resources. In addition, hypoglycemic-screening experiment showed that compound 1, 2, 6, 7, 8, 9, 10, 11 and 12 could promote normal L6 muscle cells to assimilate glucose.
Chapter 3. Review on the cucurbitane-type triterpenoids of M. charantia L.
This chapter details the cucurbitane-type triterpenoids of M. charantia L, biological activities and typical magnetic resonance signals, which provide a variety of useful informations to the people interested in cucurbitante-type triterpenoids of M. charantia L.|