Inhibitory Action of Palatinose and Its Hydrogenated Derivatives on the Hydrolysis of α-Glucosylsaccharides in the Small Intestine

This study was conducted to investigate the inhibitory effects of palatinose and Palatinit, which are disaccharides (or disaccharide alcohol) connected through an α-1,6-glucosyl linkage, on the hydrolysis of other carbohydrates, using an enzyme extract from the rat small intestine and a purified sucrase−isomaltase complex. Palatinose and its hydrogenated product, Palatinit, an equimolar mixture of α-O-d-glucopyranosyl-1,6-d-sorbitol (GPS) and α-O-d-glucopyranosyl-1,6-d-mannitol (GPM), inhibited the hydrolysis of sucrose and maltose. Palatinose and Palatinit also inhibited the hydrolysis of dextrin and soluble starch. Kinetic analysis of the enzymatic inhibition by GPS and GPM on sucrose hydrolysis revealed that both GPS and GPM competitively inhibit sucrase catalytic activity. These results suggest that disaccharides with an α-1,6-glucosyl linkage competitively inhibit intestinal α-glucosidases and may reduce the rate of hydrolysis of sucrose and other α-glucosylsaccharides.