Studies On The Isolation, Identification And Cytotoxic Activities Of The Rare Ginsenosides Transformed From Ginsenoside-Re

Ginseng, the roots of Panax ginseng C. A. Meyer belonging to Araliaceae Plants, is well-known as the king of herbs and has been discovered and applied as the important medicinal resource for 2000 years in China. As described in the earliest medical classics in China “Shen Nong’s Herbal Classic”, is as follows: It can be used to nourish internal organs,remove evil influence, stabilize the psyche, brighten eyes and benefit wisdom, prevent being horrified. Regularly taking ginseng is good for longevity. Because of the high medicinal value of ginseng, it was rewarded and respected by the scholars at home and abroad. With the development of modern science and technology, especially afrer the column chromatography and spectral identification technology were popularized in 1960 s, the studies of ginseng have achieved fruitful results.A large number of modern chemical researches have validated that ginseng contains ginsenosides, ginseng peptides and proteins, ginseng polysaccharides, ginseng alkynyl alcohols, etc. But the ginsenosides are the symbol of the ginseng ingredients, and moden medicine and pharmacology have proved they have important biological functions such as immunoregulatory, retarding aging, anti-fatigue, anti-tumor and protecting cardio-cerebral-vascular systerm, and so on. Ginsenosides, which are part of triterpenoid, are divided into dammarane type including PPT and PPD, ocotillon type triterpenoid saponin,oleanolicacid type and other type based on their aglycones.In order to search more effective rare ginsenosides with anti-cancer activity, we degraded ginsenoside Re under a strong alkaline condition using glycerol as solvent and obtained six compounds including two new triterpenoid saponins and four known ginsenosides. Their structures were elucidated on the basis of spectroscopic analyses,including 1D, 2D NMR and HR-ESI-MS. They are 20(S)-PPT(I)、20(S)-ginsenoside Rh1(II)、(20R, 22E)-6-O-β-D-glucopyranosyl-dammar-22(23), 24-diene-3β, 6α, 12β-triol(III)、(20S,22E)-6-O-β-D-glucopyranosyl-dammar-22(23), 24-diene-3β, 6α, 12β-triol(IV)、Ginsenoside Rk3(V) and(20 E)-ginsenoside F4(VI). Among them,(20R, 22E)-6-O-β-D-glucopyranosyl-dammar-22(23), 24-diene-3β, 6α, 12β-triol(III) and(20S,22E)-6-O-β-D-glucopyranosyl-dammar-22(23), 24-diene-3β, 6α, 12β-triol(IV) were identified as new triterpenoid saponins.There was no report about these new compounds’ biological properties. Thus, they were subjected to assay for cytotoxic activities against five human tumor cells lines(A549 cell line,C6 cell line, He La cell line, Hep G2 cell line and MCF-7 cell line) using3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium(MTT) assay. The results displayed that(20S, 22E)-6-O-β-D-glucopyranosyl-dammar-22(23), 24-diene-3β, 6α, 12β-triol(III) had cytotoxic activity against C6.