20-Protopanaxadiol

FIGURE 1.2 Possible metabolism (degradation pathway) of protopanaxadiol-type gin-senosides such as ginsenoside Rbi by stomach acidity and by human intestinal bacteria. 

FIGURE 1.5 Possible biosynthetic route for ginsenosides of the dammarenediol-, protopanaxadiol-, and protopanaxatriol-type via dammarenediol. 

Cui, J.-F., Bjorkhem, 1., and Eneroth, P. (1997). Gas chromatographic-mass spectrometric determination of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol for study on human urinary excretion of ginsenosides after ingestion of ginseng preparations. /. Chromatogr. B 689, 349-355. 

Lee, J.-Y., Shin, J.-W., Chun, K.-S., Park, K.-K., Chung, W.-Y., Bang, Y.-J., Sung, J.-H., and Surh, Y.-J. (2005). Antitumor promotional effects of a novel intestinal bacterial metabolite (lH-901) derived from protopanaxadiol-type ginsenosides in mouse skin. Carcinogenesis 26, 359-367. 

Park, E.-J., Zhao, Y.-Z., Kim, J., and Sohn, D. H. (2006). A ginsenoside metabolite 20-O-P-D-glucopyranosyl-20(S)-protopanaxadiol, triggers apoptosis in activated rat hepatic stellate cells via caspase-3 activation. Planta Med. 11,1250-1253. 

Popovich, D. G., and Kitts, D. D. (2004b). Mechanistic studies on protopanaxadiol, Rh2, and ginseng Panax quinquefolium) extract induced cytotoxicity in intestinal Caco-2 cells. /. Biochem. Mol. Toxicol. 18,143-149. 

Shibata, S., Tanaka, O., Ando, T., Sado, M., Tsushima, S., and Ohsawa, T. (1966). Chemical studies on oriental plant drugs. XIV. Protopanaxadiol, a genuin sapogenin of ginseng saponins. Cheni. Pharm. Bull. 14, 595-600. 

Tohda, C., Matsumoto, N., Zou, K., Meselhy, M. R., and Komatsu, K. (2002). Axonal and dendritic extension by protopanaxadiol-type saponins from ginseng drugs in SK-N-SH cells. Jpn. J. Pharmacol. 90, 254-262. 

Wakabayashi, C., Hasegawa, H., Murata, J., and Saiki, 1. (1997). In vivo antimetastatic action of ginseng protopanaxadiol saponins is based on their intestinal bacterial metabolites after oral administration. Oncol. Res. 9, 411-417. 

Fig. 2.2 Structures of common ginsenosides. The core damarane structure common to ginsenosides is shown along with the carbon skeletons of the 20(S)-protopanaxadiol and 20(S)-protopanaxatriol ginsenosides. The sugar decorations of the most common ginsenosides are indicated in the table below the structures. Legend Ara(/), arabinose (furanose form) Ara(p), arabinose (pyranose form) Glc, glucose...

Fig. 7.1 Chemical structures of six major ginsenosides - (a) protopanaxadiol and (b) protopanax-atriol...

A study we performed with mini pigs in cooperation with the University of Zurich30 showed, after intravenous administration, that the derivatives of protopanaxatriol, as Rglr have a one compartment pharmacokinetic profile, and a half-life of about 30 min. Whereas for the derivatives of protopanaxadiol, such as Rbj, the half-life is much longer, about 16 h, and its pharmacokinetics is described with a two-compartment model (Figure 16.30). 

J.F. Cui, Dose Dependent Urinary Excretion of 20(S)-Protopanaxadiol and 20(S) Protopanaxa-triol Glycosides in Man after Ingestion of Ginseng Preparations — A Pilot Study, Dissertation, Karolinska Institute, Huddinge Hospital, Stockholm, Sweden, 1995. 

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