Abstract
Autoxidation of ascorbic acid (AsA) in the presence of Cu2+ generates some oxygen radicals, which induce the cleavage of glucosidic linkages of β-cyclodextrin (β-CD). The oxidative cleavage of β-CD gave several kinds of oligosaccharides and their reducing terminal sugars were mainly D-glucose. D-Erythrose, D-threose, D-arabinose, and D-xylose were also detected as minor reducing terminals by GLC and GC-MS analyses. From the experiments using several radical scavengers, the hydroxyl radical (OH radical) was identified as the main active radical.
During this reaction, 2-thiobarbituric acid reactive substances (TBARS) were produced by the oxidative degradation of β-CD, but their chemical structures and formation mechanism are still unknown.
