Study On The Process Of Degradating Panaxatriol Saponins In Stems And Leaves In Alkaline Conditions And Structure Modification Of The Products

Panax ginseng C.A.Meyer, which prefers to live in cool and humid climate, is afamous Chinese medical herb and known as the "King of Herbs".It gets such a name,because of its hypertrophy and forked roots, which highly resemble the shape of ahuman body. It mainly contains volatile oils,amino acids,vitamins,sugars, flavonoidsand trace elements. As the characteristic ingredients of Panax ginseng, ginsenosidescan be divided into five types according to their own unique structures: oleanic acid typesaponins, protopanaxadiol type saponins, protopanaxatriol type saponins, ocotillol typesaponins and the other type of saponins. Pharmacological research shows thatginsenosides have lots of pharmacological activities such as improving immunefunctions, anti-aging， anti-fatigue and anti-tumor, adjusting the central nervoussystem and the endocrine system, etc.With the advancement of technology and the more and more importance peopleattach to the traditional Chinese medicine, many researchers have been engaged inthe pharmacological activity of ginsenosides. Their efforts have shown that the majormetabolic pathways of ginsenosides in the body are deglycosylation reactions, whichproduce the secondary ginsenosides and basic saponins. However, they are verydifficult to get because of the limited amount, and this increases the difficulty for itsfurther clinical research and applications.In order to obtain low content but high pharmacological effect ginsenosides.Firstly, this thesis carried out a systematic study of degradating ginsen panaxatriolsaponins in leaves and stems in alkaline conditions, including alkaline concentration,reaction time and temperature, the data of orthogonal experiment showed thesuitable conditions of preparing of20(S)-PPT; Secondly, protection amino acid wasused to modify the structure of20(S)-PPT and ginsenoside Re, attaining the greaterbiological activity of ginsenoside derivatives by comparing the proportion ofreactants,the amount of catalyst and reaction time; Thirdly, six compounds were isolated from the products and identified by the spectral methods of1H-NMR、13C-NMR. They are3,6-O-DiBoc–glycyl-dammar-24-ene-3β,6α,12β,20S-tetraol (Ⅰ),3,6,12-O-TriBoc-glycyl-dammar-24-ene-3β,6α,12β,20S-tetraol (Ⅱ),6-O-[6’-O-Boc–glycyl-α-L-rhamnopyranosyl-(1-2)-β-D-glucopyranosyl]-20-O-[6’’’-O-Boc–glycyl-β-D-glucopyranosyl]-dammar-24-ene-3β,6α,12β,20S-tetraol(Ⅲ),6-O-[4’’-O-Boc–glycyl-α-L-rhamnopyranosyl-(1-2)-β-D-glucopyranosyl]-20-O-β-D-glucopyranosyl-24-ene-3β,6α,12β,20S-tetraol(Ⅳ),6-O-α-L-rhamnopyranosyl-(1-2)-β-D-glucopyranosyl-20-O-[3’’’-O-Boc–glycyl-β-D-glucopyranosyl]-dammar-24-ene-3β,6α,12β,20S-tetraol(Ⅴ) and6-O-[α-L-rhamnopyranosyl-(1-2)-β-D-glucopyranosyl]-20-O-[6’’’-O-Boc–glycyl-β-D-glucopyranosyl]-dammar-24-ene-3β,6α,12β,20S-tetraol (Ⅵ).In summary, all the results of the studies presented here may provide crediblefoundation for new drugs and further study.