Lipase-catalyzed regioselective synthesis of palmitolyglucose ester in ionic liquids

Abstract

Candida antarctica lipase B (CAL-B) was used as a catalyst in the synthesis of palmitolyglucose ester in the ionic liquids, 1-butyl-3-methylimidazolium triflu- oromethanesulfonate ([Bmim][TfO]), with glucose as a substrates and palmitic acid vinyl ester as the acyl donor. The effect of substrate ratio, lipase content, and temperature on the activity and stability of lipase was studied. The reaction conditions in [Bmim][TfO] re- sulting in the highest yield of the sugar ester were a temperature of 50?C, enzyme concentration of 50 mg/ mL, and a molar ratio of glucose/vinyl palmitate of 1:3. The major reaction product was purified and char- acterized by FT-IR, HPLC, MS and NMR, as being 6-O-palmitolyglucose ester. The advantages of ionic liquid vs. organic solvent were noted.