Following the Lipase Catalyzed Enantioselective Hydrolysis of Amino Acid Esters with Capillary Electrophoresis Using Contactless Conductivity Detection

The progress of the enzymatic hydrolysis of racemic Mixtures of the enantiomers of the methyl esters of serine and threonine was monitored. This was possible in a reaction vessel of 1.5 mL by direct sampling of volumes in the nanoliter-range directly into an electrophoresis capillary. Contactless conductivity detection was used for quantification as the analytes are not accessible by UV-detection in capillary electrophoresis. Porcine pancreatic lipase and wheat germ lipase both showed a preference for the L-enantiomers of both amino acid esters. The selectivity of the porcine lipase between the two L-esters of the two amino acids was also studied and it was found that the production of L-threonine had priority over L-serine. Chirality 22:331-335, 2010. (C) 2009 Wiley-Liss, Inc.