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Updated: Aug 11, 2026

Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
Fluorogenic substrates for chymotrypsin with 2-quinolinone derivatives as leaving groups
G Kokotos1, R Geiger, C Tzougraki
1Department of Chemistry, University of Athens.
Abstract:
Sensitive and convenient fluorometric assays for the determination of chymotrypsin have been developed by using the substrates Glt-Leu-Phe-NH-Meq, Glt-Phe-NH-FMeq and Glt-Leu-Phe-NH-FMeq, which have been synthesized utilizing the mixed anhydride method. The amidolytic activity of chymotrypsin was measured by the release of the highly fluorescent amine 7-amino-4-methyl-2-quinolinone (AMeq) or 7-amino-4-trifluoromethyl-2-quinolinone (AFMeq). The fluorescence properties of the synthesized substrates and the new fluorescent marker AFMeq were examined. Kinetic constants, as well as the maximum sensitivity for the hydrolysis of the new substrates, were determined. All new substrates permit a rapid and sensitive determination of chymotrypsin in a continuous assay system. As little as 0.7 ng of enzyme can be detected using the substrate Glt-Leu-Phe-NH-Meq, which is the most sensitive fluorogenic substrate thus far reported.
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