Preparation
1. Acid Degradation Method In 1966, Shibata et al. discovered that hydrochloric acid could hydrolyze a mixture of ginsenosides Rc, Rb1, and Rb2 into protopanaxadiol. In 2003, Chen Yegao et al. hydrolyzed total saponins from Panax notoginseng leaves at room temperature with concentrated hydrochloric acid, obtaining 20(R)-protopanaxadiol with a yield of 0.9%. Studies have shown that acids can cause the C-20 hydroxyl group and the double bond of the side chain to dehydrate and cyclize, forming a pair of isomers with different C-20 chiralities: 20(S)-ginsenoxadiol and 20(R)-ginsenoxadiol. Furthermore, the configuration at the C-20 position is highly susceptible to acid influence, resulting in tautomerism and a decrease in the yield of protopanaxadiol.
Description
(20)R-Protopanaxadiol is a sapogenin that has been found in
P. ginseng and has anticancer and antibacterial activities. It has a cytotoxic concentration (CC
50) value of 6.1 μM in MT-4 human T cell leukemia cells and inhibits the growth of several additional cancer cell lines, including A549 human lung carcinoma, SKOV3 human ovarian adenocarcinoma, SK-Mel-2 human melanoma, P388 and L1210 murine leukemia, and K562 human chronic leukemia cells (ED
50s = 11-26 μM). (20)R-protopanaxadiol also inhibits the growth of
H. pylori in vitro (MICs = 50-100 μg/ml).
Chemical Properties
White powder, soluble in organic solvents such as methanol, ethanol, and DMSO, derived from ginseng.
Uses
20(R)-Protopanaxdiol is a saponin ginsenoside which is a signature phytochemical of Ginseng, an herbaceous plant. Anti-cancer agent.
Definition
ChEBI: A diastereomer of protopanaxadiol in which the 20-hydroxy substituent has been introduced at the pro-R position.
References
[1] N. BAEK. Cytotoxicities of ginseng saponins and their degradation products against some cancer cell lines[J]. Archives of Pharmacal Research, 1995, 18 1: 164-168. DOI:
10.1007/bf02979189[2] H HASEGAWA. Inhibitory effect of some triterpenoid saponins on glucose transport in tumor cells and its application to in vitro cytotoxic and antiviral activities.[J]. Planta medica, 1994, 60 3: 240-243. DOI:
10.1055/s-2006-959467[3] E. BAE. Metabolism of 20(S)- and 20(R)-ginsenoside Rg3 by human intestinal bacteria and its relation to in vitro biological activities.[J]. Biological & pharmaceutical bulletin, 2002, 20 1: 58-63. DOI:
10.1248/bpb.25.58
