Isomerase activity of Candida rugosa lipase in conversion of racemic ibuprofen to (S)-ibuprofen.

摘要

The Candida rugosa lipase-catalyzed Dynamic Kinetic Resolution of racemic ibuprofen methyl ester was optimal at pH 7.6 to produce (S)-ibuprofen in 72 hours. The concentration of various buffers for these reactions ranged from 0.2 to 0.5 M. The commercial lipase was found to be acidic altering the final pH of the reaction mixtures. Dimethylformamide co-solvent maintained the reaction pH better than dimethylsulfoxide, with evidence of the latter functioning as an oxidizing agent. Lower concentrations of ibuprofen methyl ester and higher stirring rates led to faster conversions. The minimal amount of lipase needed was 20 mg/mL buffer. Reaction of ( R)-ibuprofen methyl ester under the optimized conditions excluding the lipase led to no racemization, demonstrating that the conversion of ( R)-ibuprofen methyl ester to (S)-ibuprofen is catalyzed by the enzyme.