Synthesis, characterization and antitumour activity of uracil and uracil-histidine complexes with metal(III) ions

Abstract

Complexes of the [Al(L-H)(OH)Cl], [M(L-H)(H2O)2-(OH)Cl] and [M′(L-H)(L′-H)(H2O)Cl] type, where L = uracil (URL); L′= histidine (HISD); M = CrIII or FeIII and M′= AlIII, CrIII or FeIII were synthesized and characterized. The complexes are polymers, with high decomposition points and are insoluble in water and common organic solvents. Uracil is coordinated to the metal ion through the O atom of C(4)=O and the N atom of N(1), while histidine coordinates through the O atom of -CO-2 and the N atom of the -NH2 groups. The μeff values, electronic spectral bands and e.s.r. spectra suggest a polymeric six coordinate spin-free octahedral stereochemistry for the CrIII and FeIII complexes. The in vivo and in vitro antitumour activity results indicate that CrIII and FeIII complexes have significant activity against P815 murine mastocytoma but AlIII complexes show poor activity.