INHIBITORY EFFECT OF 1,3,5-TRIPHENYL-4,5-DIHYDRO-(1H)-PYRAZOLE DERIVATIVES ON ACTIVITY OF AMINE OXIDASES

A new series of 1,3,5-triphenyl-4,5-dihydro-(1H)-pyrazole derivatives was synthesized to ascertain the contribution of substituted phenyl ri ngs present on the 4,5-dihydro-(1H)-pyrazole nucleus to the monoamine oxidases inhibition and bovine serum amine oxidase inhibition. All com pounds were tested on bovine brain mitochondria preparation containing flavin-monoamine oxidases and on purified bovine serum amine oxidases , taken as a model of trihydroxy-phenylalanine quinone-copper-containi ng amine oxidases, The 1,3,5-triphenyl-4,5-dihydro-(1H)-pyrazole deriv atives showed a good inhibitory activity and belonged to the third gen eration of monoamine oxidase inhibitors and bovine serum amine oxidase inhibitors which have the advantage of acting through a reversible mo de. Furthermore, their activity showed a good degree of selectivity to wards the bovine serum amine oxidase inhibition dependent on the subst ituents present on the phenyl ring at position 5 of the 4,5-dihydro-(1 H)-pyrazole.