Pseudomonas stutzeri lipase: a useful biocatalyst for aminolysis reactions

Abstract

The use of Pseudomonas stutzerilipase (PSL) as a biocatalyst for aminolysis reactions with bulky substrates has been investigated. PSL compared favorably to Novozym^® 435 (immobilized Candida antarcticalipase B, NOV435) in the aminolysis of various bulky methyl esters and amines. While NOV435 demonstrated a higher rate of aminolysis with methyl 2-phenylpropionic acid as the acyl donor, PSL outperformed NOV435 with secondary amines as the nucleophile. Methanol inhibition and a low affinity for bulky acyl donors were found to be the two main reasons for relatively low rates in the PSL-catalyzed aminolysis reactions. It was demonstrated that the use of molsieve 4A had a significant effect on the aminolysis rate and amide yield, since it enabled the effective removal of the inhibiting methanol from the reaction mixture.