Isolation and identification of select oligosaccharides from commercially produced total invert sugar with a proposed mechanism for their formation.
Three disaccharides were isolated and purified from a commercial total invert sugar (TIS). The structures of these compounds were determined by a combination of acid and enzymatic hydrolysis studies, chromatographic comparison to standards, and nuclear magnetic resonance spectroscopy. These carbohydrates were identified as O-alpha-D-glucopyranosyl-(1-->3)-D-fructose (IS1), O-beta-D-fructofuranosyl-(2-->6)-D-glucose (IS2), and O-alpha-D-glucopyranosyl-beta-D-glucopyranoside (IS3). On the basis of these structures a mechanism for the hydrochloric acid catalyzed hydrolysis of sucrose is proposed: protonation of the glycosidic oxygen of sucrose leading to the formation of glucopyranosyl and fructofuranosyl oxonium ions of D-glucose or D-fructose, respectively, followed by nucleophilic attack of these ions by D-glucose or D-fructose at either the alpha- or beta-face.
Department of Applied Microbiology and Food Science, College of Agriculture, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, Canada S7N 5A8.
Pushparajah
P
Thavarajah
Nicholas H
NH
Low
D001894:Borohydrides; D002849:Chromatography, Gas; D004187:Disaccharides / Q000737:chemistry; D005632:Fructose / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D006026:Glycoside Hydrolases / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000737:chemistry / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D013395:Sucrose / Q000737:chemistry
D001894:Borohydrides; D004187:Disaccharides; D009844:Oligosaccharides; D005632:Fructose; D013395:Sucrose; C025364:sodium borohydride; D006026:Glycoside Hydrolases; C008133:invert sugar; D005947:Glucose