NOVEL REGIOSELECTIVE ESTER HYDROLYSIS BY PIG-LIVER ESTERASE

Pig-liver esterase, which catalysed the hydrolysis of substrates conta ining both saturated and alpha,beta-unsaturated/cyclopropanecarboxylic esters (methyl and ethyl), was studied. An exclusive hydrolysis of th e saturated esters was observed. Kinetic experiments revealed that the presence of deactivated carbonyl in the unsaturated/cyclopropanecarbo xylic eaters and their weaker bindings are both responsible for the ob served specificity. The relative binding abilities of the substrates h ave been explained in light of Jones active-site model. The regioselec tivity has been exploited in the synthesis of intermediates for the th romboxane synthetase inhibitor.