SUBSTRATE-LIKE INHIBITORS OF DIAMINE OXIDASE - SOME RELATIONS BETWEEN STRUCTURE OF ALIPHATIC AMINOKETONES AND THEIR INHIBITORY EFFECT

Nine diamino- and monoamino-ketonic compounds were synthesized and evaluated as inhibitors of pea seedling and pig kidney cortex diamine oxidase (EC 1.4.3.6). The inhibitory effect depends upon the carbon chain length and upon the number of amino group in agreement with the general features of diamine oxidase substrate structure, proposed by Zeller et al. (18). Thus, 1,4-diamino-2-butanone (2-ketoputrescine) possesses the highest inhibitory activity. The inhibition was also dependent upon the kind and concentration of substrate used. Oxidation of 1,4-diaminobutane by plant diamine oxidase was more sensitive to almost all aminoketones tested than was the oxidation of 1,5-diaminopentane, while an animal enzyme showed the opposite behavior. © 1969.