Ethyl α-D-glucoside was absorbed in small intestine and excreted in urine as intact form

Abstract

Objective Ethyl α-D-glucoside (α-EG) is a peculiar component in sake. We investigated how α-EG was absorbed, hydrolyzed, and excreted in urine when it was ingested orally by rats. Methods Hydrolyzing activity for α-EG was determined by incubating it with crude enzyme solutions prepared from several rat organs, and absorption activity for α-EG was determined by incubating rat small intestinal everted sac in sodium or potassium Krebs-Ringer buffer that contained α-EG. α-EG solution was fed to rats, and urine volume and plasma α-EG, glucose and insulin and urinary α-EG were determined. Results α-EG was hydrolyzed by crude enzyme solutions prepared from rat small intestinal mucosa and kidney, and these hydrolyzing activities were lower than those for maltose. α-EG absorbed into everted rat intestinal sacs in potassium Krebs-Ringer buffer reduced almost completely compared with that in sodium Krebs-Ringer buffer. When α-EG was ingested orally by rats, it was absorbed into the bloodstream and more than 60% was excreted in urine, and urine volume increased. Conclusions In rats, α-EG was absorbed in small intestine and excreted intact in urine without affecting blood glucose and insulin and thus was a diuretic, insulin-independent, and low-nutritive glucoside that could be safely applicable to food.