METAL ION-DRUG INTERACTIONS - PREPARATION AND PROPERTIES OF MANGANESE(II), COBALT(II) AND NICKEL(II) COMPLEXES OF DICLOFENAC WITH POTENTIALLY INTERESTING ANTIINFLAMMATORY ACTIVITY - BEHAVIOR IN THE OXIDATION OF 3,5-DI-TERT-BUTYL-O-CATECHOL

Some new complexes of diclofenac with potentially interesting biologic al activity are described. The complexes of diclofenac [MnL2(H2O)], [C oL2(H2O)(2)](.)0.5H(2)O, [CoL2(H2O)], [NiL2(H2O)(2)](.)2H(2)O, and [Ni L2], were prepared by the reaction of the sodium salt, of a potent ant i-inflammatory drug with MnCl2, CoCl2 and NiCl2. 6H(2)O. Optical, EPR, infrared and electrochemical properties of these new complexes are re ported. Both five and six-coordinated species were isolated in the sol id state for Co(II). Both four and six-coordinated species were isolat ed in the solid state for Ni(II), while in DMF or MeOH solution predom inant formation of six-coordinated species is observed for Co(II) and Ni(II) complexes. The ability of the complexes to catalyze the oxidati on of 3,5-di-tert-butyl-o-catechol to 3,5-di-tert-butyl-o-quinone was studied by following the appearance of quinone spectrophotometrically. Correlation of the catalytic activity of these complexes to the reduc tion potential is reported. (C) 1998 Elsevier Science Inc. All rights reserved.