Studies On The Rare Targets Of Acid Transform Ginsenoside-re

Panax ginseng C.A.Meryer belongs to Araliaceae perennial herb, which is famous as the king of herbs and one of the world’s higher sales of medicinal plants. Ginsenosides are considered as the major pharmacologically active ingredients of ginseng and they belong to tetracyclic triterpenoid saponins, which have a lot of pharmacological activity such as anti-tumor, anti-aging, improving cognition, central nervous system, immune system, liver function, hematopoietic system and regulating metabolism, etc.The study on the structure-activity relationship of ginsenosides found that the nucleus configuration, the number and location of sugar and the side chain diverse all have a key role to the pharmacological response.As mentioned above, some ginsenosides which have good activities but their contents in natural products are very little. We choose Re as raw material for its rich content and easy extraction in ginseng to find the optimum transformation and separation conditions to get the rare secondary structures of 20(R)-ginsenoside-Rg2, 20(S)-ginsenoside-Rg2 and other 2 new compounds.Six compounds were isolated from the products and obtained identification according to their physical and chemical properties, and 1H-NMR, 13C-NMR, HMQC, HMBC spectral datas. They are 20(R)-ginsenoside-Rg2(I), 20(S)-ginsenoside-Rg2(II) and compounds(III), ginsenoside-Rg6(IV), 20(E)-pseudoginsenoside-Rg2(V) and 20(Z)-pseudoginsenoside-Rg2. The compound II can be directly isolated from ginseng, and the others are not exist in natural products. Compound(III) and 20(Z)-pseudoginsenoside-Rg2(VI) are new types of ginsenosides.The compound III, 20(E)-pseudoginsenoside-Rg2, 20(Z)-pseudoginsenoside-Rg2, 20(S)-ginsenoside-Rg2 have been pharmacological activity test by 5 kinds of human cancer cells(A549, C6, Hela, Hep G2, MCF-7). 20(E)-pseudoginsenoside-Rg2 and 20(S)-ginsenoside-Rg2 inhibited cancer cells are not obvious, compound III and 20(Z)-pseudoginsenoside-Rg2 have certain inhibition on cancer cells and have shown good dose effect relationship. The 20(E) and 20(Z)-pseudoginsenoside-Rg2 have different pharmacological activities showing that the configuration of C-20(22) double bond has different effect on the biological activity. Compounds III can significantly inhibit the growth of human glioma C6 cells.This paper determined the preparation and separation process of ginsenoside-Re acid transform rare secondary ginsenosides. The structure of these products were identified and parts of the monomers were studied on pharmacological activity. They have got enlightenment on researching the development of new drugs.We have proved a new path of C-20 hydroxyl elimination and C-25 hydroxyl adduct in the side chain of ginsenoside, and it provide a solid foundation to obtain new related series of products by our laboratory.