Abstract:In the study, the preparation of 2-O-α-D-glucosyl-L-ascorbic acid (AA-2G) using L-ascorbic acid and β-cyclodextrin as substrates was carried out by marine cyclodextrin glucosyltransferase MY20. The purification process and antioxidant activity of AA-2G were investigated. By using the cationic ion exchange resin SK1B and the anionic ion exchange resin WA30. The process parameters for separating AA-2G from anion exchange resin WA30 were optimized. The optimal process parameters were determined through response surface experiments, with the eluent concentration set at 0.15 mol/L, the eluent flow rate at 3.00 mL/min, and the eluent pH at 7.00. Under these conditions, the purity of AA-2G purified was found to be 91.23wt.%, with a recovery rate of 89.92wt.%. Subsequently, a multi-step purification process was established based on this, leading to an increase in the purity of AA-2G from the initial 50.31wt.% to 95.62wt.%, resulting in a 1.90-fold purity increase and a recovery rate of 85.12wt.%. In vitro antioxidant analysis of the prepared AA-2G revealed clearance rates of 91.63% for superoxide anion, 90.21% for hydroxyl radical, and 95.20% for DPPH radical, confirming the antioxidant activity of AA-2G enzymatically prepared. The study provides a theoretical basis for the development of high-purity AA-2G.
