Preparation and Characterization of Acid Hydrolysis Products of the Tomato Glycoalkaloid α-Tomatine

Abstract

As part of an effort to define the biological roles of carbohydrate groups of the tomato glycoalkaloid α-tomatine in plants and animals, experiments were carried out to optimize the acid hydrolysis of the tetrasaccharide side chain of α-tomatine to products with three, two, one, and zero sugar groups. This was accomplished by following the time course for hydrolysis in 1 N HCl at 100 °C, isolating the hydrolysis products by chromatography on an aluminum oxide column, and determining the number and nature of hydrolysis products, including free sugars, with the aid of thin-layer chromatography and gas chromatography/mass spectrometry of alditol acetate sugar derivatives. The results show that a 20-min hydrolysis time appears useful for the formation of a mixture of the monosaccharide δ-tomatine, the disaccharide γ-tomatine, and the trisaccharide β1-tomatine. Efforts to isolate the other possible trisaccharide, β2-tomatine, were unsuccessful, apparently because xylose is degraded during the hydrolysis. A 70-...