Studies on Absorption, Distribution, Excretion and Metabolism of Ginseng Saponins. VIII. Isotope Labeling of Ginsenoside Rb₂

Abstract

To clarify the pharmacokinetics of absorption, distribution and excretion of ginsenoside Rb₂ (Rb₂), one of the major saponins of the root of Panax ginseng, following oral administration to rats, a tritium (³H) labeling of Rb₂ was examined. The C-12 position of Rb₂ was labeled with ³H-sodium borohydride (³H-NaBH₄) and 12-³H Rb₂ and 12-³H-epi Rb₂ was synthesized. This method of specific position labeling of Rb₂ may be applicable to other ginsenosides. In the near future, the pharmacokinetics of Rb₂ in rats may be clarified with ³H labeled Rb₂.