Process and reagent for the determination of substrates or enzyme activities

摘要

A process for the determination of substrate or enzyme activities by the use of a redox reaction as a measurement reaction is carried out in the presence of one or more additionally added tetrazolium salts to remove disturbing substances. The tetrazolium salts have the formula (I) in which R1 is a hydrogen atom, a carboxyl group or an alkyl, phenyl, nitrophenyl, dinitrophenyl, carboxyl-substituted phenyl or trialkylammoniumphenyl radical, R2 is a phenyl, nitrophenyl, biphenylyl or naphthyl radical, R3 is a phenyl, carboxyl-substituted phenyl, carboxyl-substituted hydroxyphenyl or dimethylthiazolyl radical, and A(-) is a monovalent anion. The formazanes formed by reaction with reducing substances do not absorb light at all, or absorb light only to a negligible extent, at the measurement wavelength of the redox reaction. New compounds included within the structural formula are those in which R1 is carboxy, phenyl, 2-carboxyphenyl, 4-carboxyphenyl, 2,4-dinitrophenyl or 4-trimethylammoniumphenyl, R2 is phenyl, and R3 is phenyl or 2-carboxyphenyl; with the proviso that, when R3 is unsubstituted phenyl or 2-carboxyphenyl, R1 may not be unsubstituted phenyl.