Identification and quantification of ginsenosides in various commercial ginseng preparations

Abstract

Recently developed accurate GC and GC-MS methods were used to characterize various commercial ginseng preparations purchased from pharmacies or well reputed health stores in seven European countries, Argentina, Canada, China and the USA. The methods used are based on quantification of the aglycones (20s-protopanaxadiol, 20s-protopanaxatriol and oleanolic acid) of the ginsenosides after oxidative cleavage in alkali. The most pure ginseng preparations ( n = 14) contained from 1.9% to 8.1% (w/w) ginsenosides (using ginsenoside Rg 1, Rb 1 and Ro as calibrators and panaxatriol as internal standard). The content of ginsenosides in different ginseng extracts (in 20 ginseng extract preparations) varied from 4.9% to 13.3% (w/w). Some liquid formulations as well as some preparations of red ginseng were shown to contain artifacts (epimerization and hydration products of 20s-protopanaxadiol and 20s-protopanaxatriol). The latter compounds are not likely to be detected by the common HPLC analysis of intact ginsenosides. American ginseng and San-chi ginseng were also analyzed. The present method is suitable for evaluation of different types of ginseng preparations.