Leucrose is a reducing disaccharide and a bond isomer of sucrose with the chemical structure D-glucopyranosyl-α(1→5)-D-fructopyranose. Unlike sucrose, which has an α-(1→2) glycosidic linkage, leucrose features an α-(1→5) bond, giving it increased resistance to acid hydrolysis.

First identified as a natural byproduct in honey maturation and present in low concentrations in microbial cultures, leucrose exhibits about 40-50% of the sweetness of sucrose. It crystallizes as a monohydrate and melts at approximately 156-158 °C.

Leucrose is metabolized in the human small intestine by α-glucosidase enzymes into glucose and fructose, making it a digestible carbohydrate. Its chemical stability and moderate sweetness make it a promising sweetener alternative.

Industrial Synthesis

Industrial synthesis of leucrose involves transglycosylation reactions transferring a glucose unit from sucrose to free fructose, forming the α-(1→5) linkage with high conversion efficiency (85-95%).

In summary, leucrose is a naturally occurring reducing disaccharide isomeric to sucrose with an α-(1→5) glycosidic bond, possessing unique physicochemical and biological properties with potential applications in food and biochemical industries.