초록
<P>The ginsenoside 20-<I>O</I>-β-glucopyranosyl-20(<I>S</I>)-protopanaxadiol, compound K, has attracted much attention in functional food, traditional medicine, and cosmetic industries because of diverse pharmaceutical activities. The effective production of compound K from ginseng extracts has been required. However, an enzyme capable of completely converting all protopanaxadiol (PPD)-type ginsenosides to compound K has not been reported until now. In this study, unlike other enzymes, β-glucosidase from <I>Caldicellulosiruptor bescii</I> was able to hydrolyze sugar moieties such as <SMALL>L</SMALL>-arabinofuranose as well as <SMALL>D</SMALL>-glucose and <SMALL>L</SMALL>-arabinopyranose as the C-20 outer sugar in ginsenosides. Thus, ginsenoside Rc containing <SMALL>L</SMALL>-arabinofuranose can be converted to compound K by only this enzyme. Under the optimized reaction conditions, the enzyme completely converted PPD-type ginsenosides in ginseng extracts to compound K with the highest productivity among the reported results. This is the first report of the enzyme capable of completely converting all PPD-type ginsenosides into compound K.</P><BR>[FIG OMISSION]</BR>