Studies On Chemical Constituents And Pharmacological Activities Of The Stems And Leaves Of Dioscorea Nipponica Makino

In this paper the chemical constituents and pharmacological activities of the stems and leaves of Dioscorea nipponica Makino were studied. According to the references,the rhizomes of D. nipponica is not only the main medical resource to cure cardiovascular disease, but also the important raw materials for obtaining diosgenin, which is used for producing hormone-medicine and contraceptives. Clinical researches showed that the constituents from the rhizomes of D. nipponica had the effects of anti-tumor, immunological regulation, blood fat regulation, and so on. But most studies on it were focus on the part of rhizomes. In order to exploit new medicinal herbs resource, our group researched the stems and leaves of D. nipponica systematically for the first time.The process and results of the research as follow: Firstly,the dried stems and leaves of Dioscorea nipponica Makino were collected from Jingyu, Jilin province, extracted with alcohol of 70%. Secondly, the alcohol extraction was evaporated with distillation method at normal pressure in order to be concentrated to relative density to 1.12. Thirdly, the concentrated solution was dissolved with water. Then, the solution was extracted with petroleum ether, chloroform, ethyl acetate and n-butanol respectively. Finally, ten compounds were obtained from petroleum ether and n-butyl extracts, which were separated with silica gel column chromatography by using several kinds of solvent systems, purified by recrystallization repeatly. Among of them, eight compounds structures were identified on the basis of chemical and spectroscopy evidence (1H NMR, 13C NMR, HMBC). they are as follow: 7-O-(ρ- benzoic acid)- kaempferol(Ⅰ), ergosterolperoxide(Ⅱ),kaempferol(Ⅲ),ρ-hydroxybenzoic acid(Ⅳ),ρ-hydroxyphenyl ethyl acid(Ⅴ),β-Sitosterol(Ⅵ), daucosterol(Ⅶ), diosgenin(Ⅷ). And among them compoundⅠis new, compoundⅡis isolated from the genus Dioscorea for the first time.The pharmacological activities of the water extraction and total saponin fraction of the stems and leaves of D. nipponica on regulating blood lipids were studied on experimental hyperlipidemia mice. The results showed that both of the above parts had the effects of decreasing the contents of total cholesterol (TC), low density lipoprotein (LDL-C), and increasing the contents of High density lipoprotein (HDL-C), as well as decreasing the value of TC /HDL-C.The studies indicated that the water extract and total saponin fraction of aerial parts of D. nipponica possessed hypolipidemic effect on experimental hyperlipidemia mice.