Kinetics of enzymatic synthesis of monoferuloyl glycerol and diferuloyl glycerol by transesterification in [BMIM]PF6

Feruloyl glycerols (FGs), water-soluble glycerides (monoferuloyl glycerol (MFG) and diferuloyl glycerol (DFG)) of ferulic acid, can be used as natural ultraviolet (UV) filters and antioxidants in chemical, food, pharmaceuticals, and drug industries. In order to promote the synthesis of FGs, the effect of process parameters, optimization, thermodynamic and kinetic properties on the enzymatic transesterification of ethyl ferulate (EF) with glycerol in [BMIM]PF6 were investigated. The maximum yields of MFG (63.72 +/- 11.26%) and DFG (78.80 +/- 12.09%) were achieved at low glycerol concentrations in [BMIM]PF6. The activation energies for EF conversion and transesterification to form MFG and DFG were calculated as 40.16, 31.43 and 85.38 kJ/mol, respectively, based on the Arrhenius law. Reaction kinetics agreed with the Ping-Pong Bi-Bi mechanism with the inhibitions of EF and glycerol. The enzymatic mechanism of the transesterification of EF with glycerol in [BMIM]PF6 was also proposed. (C) 2015 Elsevier B.V. All rights reserved.