GINSENOSIDE RG(5), A GENUINE DAMMARANE GLYCOSIDE FROM KOREAN RED GINSENG

A genuine dammarane glycoside, named ginsenoside Rg,, has been isolate d by repeated column chromatography and preparative HPLC from the MeOH extract of Korean red ginseng (Panax ginseng C.A. Meyer). The chemica l structure of ginsenoside Rg(5) was determined as 3-O-[beta-D-glucopy ranosyl (1-->2)-beta-D-glucopyranosyl] dammar-20(22),24-diene-3 beta,1 2 beta-diol by spectral and chemical methods. The stereostructure of a double bond at C-20(22) of ginsenoside Rg, was characterized as (E) f rom the chemical shift of C-21 in the C-13-NMR and a NOESY experiment in the H-1-NMR.