A new mathematical method for determining the enantiomeric ratio in lipase-catalyzed reactions

We present a new mathematical method for determining the enantiomeric ratio (E) during lipase-catalyzed kinetic resolutions. The method involves the fitting of a model to profiles of adimensionalized concentrations of the two enantiomers of the chiral substrate, plotted against degree of conversion. The model equations are presented for a reversible reaction involving bi-bi ping-pong kinetics in which the chiral substrate enters second and the chiral product leaves second. However, it is also shown that the method is easy to modify for analysis of resolutions involving other chiral substrate-product pairs and of resolutions in which the behavior of the system can be approximated by irreversible uni-uni kinetics. We show that our method retains several advantageous features of existing methods that help to ensure accuracy.