Biological activities of ginseng saponins (ginsenosides) are associated with type, number and position of sugar moieties linked to aglycone skeletons. Deglycosylated minor ginsenosides are known as more biologically active than major ginsenosides. Accordingly, the deglycosylation of major ginsenosides can provide the multi-bioactive effects of ginsenosides. The purpose of this study was to transform ginsenoside Rb2, one of the protopanaxadiol-type major ginsenosides, into minor ginsenosides using β-glycosidase (BG−1) purified from Armillaria mellea mycelium.