Lipozyme 435-Mediated Synthesis of Xylose Oleate in Methyl Ethyl Ketone
Maria Carolina Pereira Gonçalves,
Jéssica Cristina Amaral,
Roberto Fernandez-Lafuente,
Ruy de Sousa Junior,
Paulo Waldir Tardioli
Affiliations
Maria Carolina Pereira Gonçalves
Postgraduate Program in Chemical Engineering, Laboratory of Enzyme Technologies (LabEnz), Department of Chemical Engineering, Federal University of São Carlos (UFSCar), Rodovia Washington Luís, km 235, São Carlos 13565-905, SP, Brazil
Jéssica Cristina Amaral
Postgraduate Program in Chemistry, Laboratory of Natural Products, Department of Chemistry, Federal University of São Carlos (UFSCar), Rodovia Washington Luís, km 235, São Carlos 13565-905, SP, Brazil
Roberto Fernandez-Lafuente
Departamento de Biocatálisis, ICP-CSIC, Campus UAM-CSIC, 28049 Madrid, Spain
Ruy de Sousa Junior
Postgraduate Program in Chemical Engineering, Laboratory for Development and Automation of Bioprocesses (LaDABio), Department of Chemical Engineering, Federal University of São Carlos (UFSCar), Rodovia Washington Luís, km 235, São Carlos 13565-905, SP, Brazil
Paulo Waldir Tardioli
Postgraduate Program in Chemical Engineering, Laboratory of Enzyme Technologies (LabEnz), Department of Chemical Engineering, Federal University of São Carlos (UFSCar), Rodovia Washington Luís, km 235, São Carlos 13565-905, SP, Brazil
In this paper, we have performed the Lipozyme 435-catalyzed synthesis of xylose oleate in methyl ethyl ketone (MEK) from xylose and oleic acid. The effects of substrates’ molar ratios, reaction temperature, reaction time on esterification rates, and Lipozyme 435 reuse were studied. Results showed that an excess of oleic acid (xylose: oleic acid molar ratio of 1:5) significantly favored the reaction, yielding 98% of xylose conversion and 31% oleic acid conversion after 24 h-reaction (mainly to xylose mono- and dioleate, as confirmed by mass spectrometry). The highest Lipozyme 435 activities occurred between 55 and 70 °C. The predicted Ping Pong Bi Bi kinetic model fitted very well to the experimental data and there was no evidence of inhibitions in the range assessed. The reaction product was purified and presented an emulsion capacity close to that of a commercial sugar ester detergent. Finally, the repeated use of Lipozyme 435 showed a reduction in the reaction yields (by 48 and 19% in the xylose and oleic acid conversions, respectively), after ten 12 h-cycles.
