Efficient mono-acylation of fructose by lipase-catalyzed esterification in ionic liquid co-solvents. (30th October 2015)

• Record Type: Journal Article
• Authors: Li, Lu; Ji, Fangling; Wang, Jingyun; Jiang, Bo; Li, Yachen; Bao, Yongming
• Is Part Of: Carbohydrate research. Volume 416(2015)
• Page Start: 51
• Page End: 58
• Publication Date: 2015-10-30
• Subjects: Sugar ester of fatty acid -- Monolauroyl fructose -- Candida antarctica lipase B -- Ionic liquids -- Kinetics; ILs ionic liquids -- 2M2B 2-methyl-2-butanol -- CALB Candida antarctica lipase B -- [BMIM][TfO] 1-butyl-3-methylimidazolium trifluoromethanesulfonate -- [BMIM][BF4] 1-butyl-3-methylimidazolium tetrafluoroborate -- [BMIM][PF6] 1-butyl-3-methylimidazolium hexafluorophosphate -- ATR–FTIR attenuated total reflectance-Fourier transform infrared -- HPLC–ELSD high performance liquid chromatography–evaporative light scattering detector -- NMR nuclear magnetic resonance -- API–MS atmospheric pressure ionization–mass spectrometry -- ANOVA analysis of variance; Carbohydrates -- Periodicals; Chemistry, Organic -- Periodicals; Biochemistry -- Periodicals; Carbohydrates -- Periodicals; Chimie organique -- Périodiques; Glucides -- Périodiques; Biochemistry; Carbohydrates; Chemistry, Organic; Periodicals; Electronic journals; 507.78
• DOI: 10.1016/j.carres.2015.08.009
• Languages: English
• ISSNs: 0008-6215

Abstract

Highlights: Markedly improved fructose mono-acylation catalyzed by CALB in ILs/2M2B co-solvent system. Selectivity of mono-acylation in ILs/2M2B co-solvent governed by the change of CALB kinetic parameters. Kinetic parameters variance determined by conformational changes of CALB binding substrates. Graphical abstract: Abstract: Fructose monoesters are eco-friendly nonionic surfactants in various applications. Selective preparation of mono-acylated fructose is challenging due to the multiple hydroxyl sites available for acylation both chemically and enzymatically. Ionic liquids (ILs) have profound impacts not only on the reaction media but also on the catalytic properties of enzymes in the acylation process. In this study, utilizing an IL co-solvent system, selective synthesis of mono-acylated fructose with lauric acid catalyzed by immobilized Candida antarctica lipase B (CALB) was investigated. The imidazolium-based ILs selected as co-solvents with 2-methyl-2-butanol (2M2B) markedly improved the ratios of monolauroyl fructose in the presence of 60% [BMIM][TfO] (v/v) and 20% [BMIM][BF4 ] (v/v), in which the mono-acylated fructose was 85% and 78% respectively. Based on a Ping-Pong Bi−Bi model, a kinetic equation was fitted, by which the kinetic parameters revealed that the affinity between fructose and acyl-enzyme intermediate was enhanced. The inhibition effect of fructose on free enzyme was weakened in the presence of IL co-solvents. The conformation of CALB binding substrates also changed in the co-solvent system as demonstrated by Fourier transform infrared spectra. These results demonstrated that the variation of CALB kinetic characteristics was a crucial factor for the selectivity of mono-acylation in ILs/2M2B co-solvents.