Protopanaxatriol-type ginsenosides from the root of Panax ginseng

Ginseng, the root of Panax ginseng C. A. Meyer (Araliaceae), is one of the most important traditional medicines and functional foods. A detailed phytochemical investigation on the roots of P. ginseng led to the isolation of 6 new natural protopanaxatriol (PPT)-type ginsenosides, ginsenosides Re(1)-Re(6) (compounds 1-6), along with 10 known PPT-type ginsenosides. Their structures were elucidated on the basis of chemical and spectroscopic analyses, including high-resolution mass spectrometry (HRMS) and 1D and 2D nuclear magnetic resonance (NMR). The unusual α-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl sugar chain, as found in compounds 1 and 2, is reported in the genus Panax for the first time.