2-Oxo-1, 3-dioxols as Specific Substrates for Measurement of Arylesterase Activity

Abstract

Various 4-arylthiomethyl-2-oxo-1, 3-dioxole derivatives IIIa-o were synthesized. Their hydrolysis rates by arylesterase (EC 3.1.1.2) and cholinesterase (EC 3.1.1.8) in human serum were evaluated. Some of them were not hydrolyzed by cholinesterase, but were hydrolyzed easily by arylesterase.Among the substrates, sodium 4-((5-methyl-2-oxo-1, 3-dioxol-4-yl)methylthio)benzenesulfonate (IIIg) was selected for its substrate reactivity toward arylesterase and its good water solubility. In addition, neither aliesterase (EC 3.1.1.1), acetylesterase (EC 3.1.1.6) nor cholesterol esterase (EC 3.1.1.13)hydrolyzed the compound. IIIg is thus concluded to be a specific substrate for arylesterase.Our assay system for serum arylesterase using IIIg can be readily applied to an automatic analyzer in the diagnosis of liver cirrhosis.