| Medicinal plants have been a good source of Pharmaceutical agents. In order to search active constituents with new structures, we have systematically studied on the chemical components, especially the saponins from two plants, the genus of Gynostemma and Cynanchum wilfordii. As a result,75 compounds, including 32 new ones were isolated and identified.The genus of Gynostemma belongs to the family Cucurbitaceae. The species of Gynostemma mostly grows in southern Shaan Xi and areas south of the Yangtze River. Gynostemma total saponins are believed to be the main active components, of these, eight saponins are the same as the ginsenosides. These are the first example of ginseng saponins found outside of the Araliaceae family. The structures and their contents of the total saponins are different in different species, growing localities and time of collection. It was found that the peaks of HPLC-ELSD and LC-MS of total saponin extract of G. species produced in Hubei, Shaanxi, Jiangxi and Guangxi. In order to clarify the diference and fully comprehend the mechanism of the biological actions at the molecular level, individual gypenosides had been isolated and identified. The aglycone and sugar sequence of the saponins could determine activation or antagonism of particular nuclear receptors affecting the homeostasis of the biological function.34 saponins have been isolated and identified from the root of wild-type G. pentaphyllum in Hubei,21 of which were new ones:G1-21. Other 10 compounds:G24-30, G32-34 were isolated from the genus G. pentaphyllum for the first time. The chemical components of the wild-type one G. pentaphyllum were diversity because of long term growth period.Chemical study on the constituents of the stems and leaves of the tetraploidy G. pentaphyllum resulted in the isolation and identification of 8 main compounds,6 of which were saponins and the others were flavonoids. The 8 main compounds from the roots of the tetraploidy G. pentaphyllum were quite different from those of the stems and leaves. They share the same aglycones with different sugar side chains. The sugar side chains in the saponins of the aerial portions were much simple than those in the roots. The reason is that the aerial portions are collected 4-5 times every year, the roots is collected once in a year. Meanwhile the 8 main compounds from the roots of the tetraploidy G. pentaphyllum were the same as to those of total saponins extract of G. pentaphyllum produced in Hangzhou.Two flavonoids and one saponin were isolated from the stems and leaves of G. pentaphyllum in Jiangxi. The chemical components were different from the others G. pentaphyllum prepared as crude drugs, these can be made into tea products.Phytochemical studies on G. yixingense led to the isolation of 15 compounds, including 13 saponins and 2 long-chain sesquiterpene glycosides. Seven saponins are the same as the ginsenosides, of these 20(S)-ginsenoside Rg2,20(R)-ginsenoside Rg2,20(S)-ginsenoside Rhl, 20(R)-ginsenoside Rhl are the protopanaxatriol-type ginsenosides. Compared to G. pentaphyllum, G. yixingense has a sweeter taste (G. pentaphyllum is bitter) that makes it appreciated by consumers.Cynanchum wilfordii is widely distributed in China. Fifteen C21 steroids glycosides were isolated from the roots of C. wilfordii. The structures of the compounds were elucidated by 1D and 2D NMR spectroscopic analysis as well as by chemical degradation. Among those, Cwl-8 were new compounds, Cw10-15 were isolated from the genus C. for the first time. |
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