Über Hemmung der Leberesterase durch Ketocarbonsäureester.

Abstract

In the hydrolysis of ethylmandelic ester by liver esterase, but not by pancreatic lipase, an induction period of 60 min. was observed, after which the hydrolysis began to proceed with considerable rapidity. The induction period was directly proportional to the ester concentration and inversely proportional to the enzyme preparation concentration. It was increased by lowering the temp. After complete hydrolysis, the addition of fresh ester caused a reappearance of the phenomenon. The latter is due to the presence in the ester of an impurity, the ethyl ester of benzoylformic acid, which in concentrations of 1,5, and 50% showed latent periods of 1.5, 3.25, and 40 hrs., respectively. Oxalacetic and benzoylacetic esters showed similar induction periods. Neither the ester grouping alone nor the keto grouping alone caused the phenomenon.