Enzymatic enantioselective ester hydrolysis by carboxylesterase NP

Abstract

The enzymatic hydrolysis of a series of carboxylic esters by carboxylesterase NP has been investigated in order to determine the scope and limitations of this enzyme. α-Substituted propionates were hydrolysed with high enantioselectivity when an aromatic moiety was part of the α-substituent. Enantioselective hydrolysis could be accomplished with several α-arylpropionates, α-aryloxypropionates and N-arylalanine esters. The propionate esters yielded the propionic acids as (S)-enantiomers, whereas the alanine esters yielded the (R)- or (D)-enantiomers. Without α-aryl substituent the enzymatic hydrolysis of the propionates occurred at a lower rate without acceptable enantioselectivity.

In addition to α-substituted propionates only a few other esters were hydrolysed with high enantioselectivity by carboxylesterase NP, such as some prochiral di-substituted malonates, 1-Phenylethyl acetate was the only substrate with the chirality in the alcohol part of the ester that was found to be hydrolysed enantioselectively.

Carboxylesterase NP proves to be a powerful enzyme for the kinetic resolution of propionate esters with an aromatic ring containing α-substituent.