Production of rare ginsenosides (compound Mc, compound Y and aglycon protopanaxadiol) by beta -glucosidase from Dictyoglomus turgidum that hydrolyzes beta -linked, but not alpha -linked, sugars in ginsenosides.

摘要

Optimal hydrolytic activity of beta -glucosidase from Dictyoglomus turgidum for the ginsenoside Rd was at pH 5.5 and 80 degrees C, with a half-life of ~11 h. The enzyme hydrolysed beta -linked, but not alpha -linked, sugar moieties of ginsenosides. It produced the rare ginsenosides, aglycon protopanaxadiol (APPD), compounds Y, and Mc, via three unique transformation pathways: Rb₁->Rd->F₂->compound K->APPD, Rb₂->compound Y, and Rc->compound Mc. The enzyme converted 0.5 mM Rb₂ and 0.5 mM Rc to 0.5 mM compound Y and 0.5 mM compound Mc after 3 h, respectively, with molar conversion yields of 100%.