Enzymatic Preparation of Genuine Prosapogenin, 20(S)-Ginsenoside Rh₁, from Ginsenosides Re and Rg₁

It was found that a lactase preparation from Penicillium sp. nearly quantitatively hydrolyzed ginsenosides Re and Rg1, which are major saponins in roots of Panax ginseng, to a minor saponin, 20(S)-ginsenoside Rh1 [6-O-beta-D-glucopyranosyl-20(S)-protopanaxatriol]. This is the first report on the enzymatic preparation of ginsenoside Rh1 with a high efficiency. This enzyme also readily hydrolyzed ginsenoside Rg2 to ginsenoside Rh1.