Novel enzymatic elimination method for the chromatographic purification of ginsenoside Rb in an isomeric mixture.

BACKGROUND

The separation of isomeric compounds from a mixture is a recurring problem in chemistry and phytochemistry research. The purification of pharmacologically active ginsenoside Rb from ginseng extracts is limited by the co-existence of its isomer Rb. The aim of the present study was to develop an enzymatic elimination-combined purification method to obtain pure Rb from a mixture of isomers.

METHODS

To isolate Rb from the isomeric mixture, a simple enzymatic selective elimination method was used. A ginsenoside-transforming glycoside hydrolase (Bgp2) was employed to selectively hydrolyze Rb into ginsenoside Rd. Ginsenoside Rb was then efficiently separated from the mixture using a traditional chromatographic method.

RESULTS

Chromatographic purification of Rb was achieved using this novel enzymatic elimination-combined method, with 58.6-times higher yield and 13.1% less time than those of the traditional chromatographic method, with a lower minimum column length for purification. The novelty of this study was the use of a recombinant glycosidase for the selective elimination of the isomer. The isolated ginsenoside Rb can be used in further pharmaceutical studies.

CONCLUSIONS

Herein, we demonstrated a novel enzymatic elimination-combined purification method for the chromatographic purification of ginsenoside Rb. This method can also be applied to purify other isomeric glycoconjugates in mixtures.