| 摘要 |
<p>The invention relates to an enzymatic method of producing 4-0-β-D-galactopyranosyl-D-xylose which is used for the in vivo evaluation of intestinal lactase activity in humans. The inventive method consists in: a) reacting D-xilose with a β-D-galactopyranoside for 2 48 h in a medium buffered to pH 5 9 and at a temperature that varies between the freezing of the mixture and 45 °C, and subsequently adding 10-10,000 units of β-D-galactosidase per gram of β-D-galactopyranoside; b) stopping the reaction by deactivating the enzyme; and c) isolating and crystallising the fractions that contain 4-O-β-D-galactopyranosyl-D-xilose in a crystallisation mixture selected between acetone/methanol (5:1-20:1) and acetone/water (5:1-20:1).</p> |
