Analysis of ginsenosides by chromatography and mass spectrometry: release of 20 S-protopanaxadiol and 20 S-protopanaxatriol for quantitation.

To facilitate studies on the possible presence of ginseng products in serum, tissues, and excretions, a procedure to optimize the analysis of the ginseng specific products, i.e., ginsenosides, had to be worked out. With the present method the two sapogenins, 20S-protopanaxadiol and 20S-protopanaxatriol, can be produced from ginsenosides Rb1, Rc, Rd, Re, and Rg1 in 80% yield by using an improved alkaline cleavage procedure. In contrast to previously described acid hydrolysis procedures for ginsenosides, our alkaline conditions caused no epimerization, no hydroxylation, and no cyclization of the side chain. Furthermore, no unchanged ginsenosides were recovered. The products of alkaline and acidic cleavage were separated, identified, and characterized by GC, GC-MS, and HPLC. In contrast to alkaline cleavage, treatment with acid afforded a number of side products. The C-20S-epimers of the ginseng sapogenins could be distinguished from C-20R epimers by difference in mass spectra and retention time after trimethylsilylation.