CHITIN OR CHITOSAN OLIGOMER CONTAINING 2,5-ANHYDROMANNITOL GROUP OR 2,5-ANHYDROMANNOSE GROUP AT END AND PRODUCTION THEREOF

摘要

PURPOSE:To obtain the title oligomer useful as a food additive, etc., having low reactivity, high stability, hardly being colored, by reacting chitin or chitosan with nitrous acid in a solution having specific hydrogen ion concentration. CONSTITUTION:Chitin or chitosan is reacted with nitrous acid in a solution having hydrogen ion concentration (pH) 1-6 to give the objective oligomer which contains 2,5-anhydromannitol group shown by formula I and has a structural formula of the other end shown by formula II wherein both the ends are directly bonded or through 0-1,000 chains of structural formula shown by formula III and the chain partially contains a structural formula unit shown by formula IV to give the objective oligomer. An organic acid preferably exists in the reaction and after the reaction is over, the oligomer is neutralized with ammonia, an alkylamine or anion exchange resin.