Quenching of tryptophan fluorescence in the presence of 2,4-DNP, 2,6-DNP, 2,4-DNA and DNOC and their mechanism of toxicity.

Although they are widely used as insecticides, acaricides and fungicides in the agriculture or as raw materials in the dye industry, dinitrophenols (DNPs) are extremely noxious, death cases having been registered. These compounds produce cataracts, lower leucocyte levels, disturb the general metabolism and can cause cancer. It is also assumed that DNPs hinder the proton translocation through the mitochondrial inner membrane and therefore inhibit oxidative phosphorylation.