Lipase-Catalyzed Esterification of Phloridzin: Acyl Donor Effect on Enzymatic Affinity and Antioxidant Properties of Esters

Lipase-catalyzed acylation of phloridzin with a wide range of fatty acids and antioxidant activities of synthesized esters were investigated in this study. Polar solvents were suitable reaction media for esterification, and the highest yield was achieved in acetonitrile. By using statistically designed optimization of key experimental factors for the synthesis of phloridzil oleate as the model reaction, great improvements in achieved conversion and yield per enzyme mass were enabled. The most significant progress has been made in the cost-effectiveness of the reaction, since the specific yield of 5.45 mmol g–1 was obtained at 58 °C, with 0.09 M phloridzin, 1.17 M oleic acid, and only 0.5% (w/v) biocatalyst. All examined fatty acids were suitable acyl donors, since the chain length and unsaturation degree had slight effects on esterification and all products yielded over 70%. Phloridzil caprate, myristate, and oleate exhibited the highest antioxidant activities among the obtained esters.