Enhancement of activity and selectivity in lipase‐catalyzed transesterification in ionic liquids by the use of additives
2007; Wiley; Volume: 82; Issue: 10 Linguagem: Inglês
10.1002/jctb.1730
ISSN1097-4660
AutoresF.J. Hernández-Fernández, Antonia Pérez de los Ríos, Manuel Prieto Rubio, Demetrio Gómez, Gloria Víllora,
Tópico(s)Electrochemical sensors and biosensors
ResumoAbstract BACKGROUND: Seven ionic liquids (ILs) based on 1‐alkyl‐3‐methylimidazolium cation in combination with hexafluorophosphate and bis{(trifluoromethyl)sulfonyl}imide anions were tested as reaction media for lipase‐catalyzed transesterification in low water conditions. With the aim of improving the activity and/or selectivity of the lipase, various treatments were applied to ionic liquid media such as equilibration with aqueous solutions of salts, NaHCO 3 or Na 2 CO 3 , or the addition of a catalytic amount of a non‐reactive organic base to the reaction mixture, triethylamine. RESULTS: The treated ionic liquids were shown to be excellent media for lipase‐catalyzed ester synthesis by transesterification compared with conventional organic solvents, such as n ‐hexane. All treatments were found to enhance the synthetic activity of the enzyme, the best results being achieved with the addition of triethylamine. The addition of a catalytic amount of this base to the ILs resulted in a significant increase in both the synthetic activity and selectivity values. For instance, the synthetic activity in [emim + ][TfN 2 − ] was enhanced more than 12 times and the selectivity increased from 86% to 95% when triethylamine was used. CONCLUSION: These treatments could be easy‐to‐use approaches to improve the efficiency of enzymatic reactions in ionic liquids when the reaction does not proceed smoothly. Copyright © 2007 Society of Chemical Industry
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