Abstract: Galactosyl-β-cyclodextrin (Gal-β-CD) was synthesized under the catalysis of α-D-galactosidase derived from germinated coffee beans using melibiose as a donor and β-cyclodextrin as an acceptor. The optimum synthesis parameters were enzyme dose 20 U/g melibiose, β-CD-to-melibiose molar ratio 1:2, pH 6.5 (50 mmol/L acetate buffer), reaction time 24 h and reaction temperature 40 ℃, respectively. The product obtained under the optimized conditions was purified by preparative HPLC, and the purified product was 6-O-α-D-galactosyl-β- cyclodextrin according to ESI-MS, IR, and NMR analyses.

Key words: galactosyl-β-cyclodextrin, β-cyclodextrin, melibiose, α-D-galactosidase