Novel enzymatic elimination method for the chromatographic purification of ginsenoside Rb3 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-3 from ginseng extracts is limited by the co-existence of its isomer Rb-2. The aim of the present study was to develop an enzymatic elimination-combined purification method to obtain pure Rb-3 from a mixture of isomers.Methods: To isolate Rb-3 from the isomeric mixture, a simple enzymatic selective elimination method was used. A ginsenoside-transforming glycoside hydrolase (Bgp2) was employed to selectively hydrolyze Rb-2 into ginsenoside Rd. Ginsenoside Rb-3 was then efficiently separated from the mixture using a traditional chromatographic method.Results: Chromatographic purification of Rb-3 was achieved using this novel enzymatic eliminationcombined 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-3 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-3. This method can also be applied to purify other isomeric glycoconjugates in mixtures. (C) 2019 The Korean Society of Ginseng. Publishing services by Elsevier B.V.