Abstract
It has been demonstrated in the author's previous experiments that normal bile has a remarkable inhibitory effect on bacterial β-glucuronidase but such an effect is not ascribable to any of known constituents of bile. Experiments were undertaken to identify glucaro-1, 4-lactone, a lactone of glucaric acid and strong inhibitor of β-glucuronidase, in bile. When bile was boiled with HCl to remove bile pigments as a deposit and then dialyzed against water, the inhibitory effect disappeared. A condensate of the dialyzate, on the other hand, exhibited a remarkable inhibitory power. This fraction gave a positive qualitative reaction for sugar acids and their relatives, and revealed on paper chromatography a spot with the same Rf as reference glucaro-1, 4-lactone. Oral administration of glucaro-l, 4-lactone calcium salt to patients with biliary infection was always followed by a more than 50 per cent decrease of the bacterial β-glucuronidase activity of bile. From these results, it has been concluded that bile contains glucaro-1, 4-lactono as a normal constituent and this compound is responsible for the inhibitory effect of bile on β-glucuronidase of bacterial origin.
