Studies On Chemical Constituents Of Acid Degradation Products Of The Ginsenosides From The Leaves And Stems Of Panax Quinquefolium L.

Panax quinquefolium L., belonging to the genus of panax, araliaceae, and it is nativeto America and Canada. The another name of Panax quinquefolium L. is AmericanGinseng, which was depicted as having many pharmacological functions such asrestorative, tonic, nootropic, antiaging and so on. The pharmacologically activeconstituents of Panax quinquefolium L. are a group of dammarane-type triterpenesaponins known as ginsenosides. The most abundant ginsenosides can be subdividedinto three classes on the basis of the aglycons, dammarane type ginsenosides, oleanicacid type ginsenosides and Ocotillol type ginsenosides. It is well known thatginsenosides have significant effect in a wide range of pathological conditions andhealthcare. Up to now, it is not successful to achieve complete synthesis of ginsenosides,and it need to extract and separate from Panax ginseng or Panax quinquefolium L. tomeet the medical needs. Numerous studies demonstrate that ginsenosides have a broadrange of beneficial effects including regulating central nervous system, anti-aging,promoting the immunity of the organism, antifatigue, meliorating pathology conditionsof cardiovascular system, and inhibiting the growth of tumors and so on. Currentscientific studies have demonstrated that most ginsenosides are metabolized in vivothrough a series of deglycosylation steps into some saponins and aglycon derivativeswith stronger efficacy and easily assimilated. But these saponins and aglycon areextremely low in Panax plants and it is hard to obtain plentiful of saponins or aglyconby isolating from Panax plants, therefore it is not conducive to the development andapplication. Thus the development of saponins and aglycon derivatives with strongerefficacy and easily assimilated has an important theoretical and applied significance.There are several methods to achieve saponins and aglycon in scientific studies, acidhydrolysis, biotransformation, alkaline hydrolysis, Smith hydrolysis and enzyme hydrolysis. Based on previous research of our laboratory, the ginsenosides-hydrolysateexhibited stronger antitumor activity than total ginsenosides.In the thesis, there is a summary of the chemical constituents, hydrolysis methods,bioactivity of ginsinosides about the scientific studies of Panax. On the basis oftheoretical and experimental reports, the chemical constituents of acid degradationproducts of the ginsenosides from the Leaves and stems of Panax quinquefolium L.were studied in this project.10kinds of compounds were isolated and purified from theacid degradation products, using the chromatography such as, column chromatographyof silica gel, reversed phase silica column, semi-preparative high performance liquidchromatography and recrystallization. The chemical structures of10compounds wereelucidated by their physicochemical properties and spectrum analysis. They are,20(R)-panaxadiol (1),20(R)-panaxatriol (2), dammar-(E)-20(22)-ene-3β,12β,25-triol(3),20(R)-dammar-25-ethoxyl-3β,12β,20-triol(4),20(R),24(R)-dammar-20(24)-epoxy-3β,1β,25-triol(5),3β,6α,12β-triol-22,23,24,25,26,27-hexanordammaran-20-one(6),20(R)-dammar-3β,6α,12β,20,25-pentol(7),20(S)-dammar-3β,6α,12β,20,25-pentol(8),20(S),24(R)-dammar-20(24)-epoxy-3β,6α,12β,25-tetraol(9),6-O-β-D-glucopyranoside-dammar-20(R)-3β,6α,12β,20,25-pentol(10). Compound6was separated from the aciddegradation products of the ginsenosides from the Leaves and stems of Panaxquinquefolium L. for the first time.