Abstract:In the study, 2-O-α-D-glucosyL-L-ascorbic acid (AA-2G) was prepared using L-ascorbic acid and β-cyclodextrin as substrates under the catalytic action of marine cyclodextrin glucosyltransferase MY20. The separation and purification process and antioxidant activity of AA-2G were examined. 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: eluent concentration, 0.15 mol/L; eluent flow rate, 3.00 mL/min; eluent pH value 7. Under these conditions, the purity of AA-2G purified was 91.23 wt.%, with a recovery rate of 89.92 wt.%. On this basis, a multi-step purification process was established, in which increased the purity of AA-2G from the initial 50.31 wt.% to 95.62 wt.%, resulting in a 1.90-fold increase of purity and a recovery rate of 85.12 wt.%. In vitro antioxidant analysis of the prepared AA-2G revealed that the scavenging rates for superoxide anion, hydroxyl radical and DPPH radical were 91.63%, 90.21% and 95.20%, respectively, indicating that the enzymatically prepared AA-2G possessed antioxidant activities. The study provides a theoretical basis for the development of high-purity AA-2G.
