Design Optimization\nof a Novel Catalytic Approach\nfor Transglucosylated Isomaltooligosaccharides into Dietary Polyols\nStructures by Leuconostoc mesenteroides Dextransucrase

Polyols, or sugar alcohols, are widely used in the industry\nas\nsweeteners and food formulation ingredients, aiming to combat the\nincidence of diet-related Non-Communicable Diseases. Given the attractive\nuse of Generally Regarded As Safe (GRAS) enzymes in both academia\nand industry, this study reports on an optimized process to achieve\npolyols transglucosylation using a dextransucrase enzyme derived from Leuconostoc mesenteroides. These enzyme modifications\ncould lead to the creation of a new generation of glucosylated polyols\nwith isomalto-oligosaccharides (IMOS) structures, potentially offering\nadded functionalities such as prebiotic effects. These reactions were\nguided by a design of experiment framework, aimed at maximizing the\nyields of potential new sweeteners. Under the optimized conditions,\ndextransucrase first cleared the glycosidic bond of sucrose, releasing\nfructose with the formation of an enzyme-glucosyl covalent intermediate\ncomplex. Then, the acceptor substrate (i.e., polyols) is bound to\nthe enzyme-glucosyl intermediate, resulting in the transfer of glucosyl\nunit to the tested polyols. Structural insights into the reaction\nproducts were obtained through nuclear maneic resonance (NMR) and\nmatrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)\nanalyses, which revealed the presence of linear α(1 →\n6) glycosidic linkages attached to the polyols, yielding oligosaccharide\nstructures containing from 4 to 10 glucose residues. These new polyols-based\noligosaccharides hold promise as innovative prebiotic sweeteners,\npotentially offering valuable health benefits.