The Superoxide Dismutase-Like Activity of Some Copper (II) Complexes Derived from Tridentate Schiff Bases

Abstract

Oxygen free radicals are the final or intermediate products of many metabolic reactions. Of greatest significance to the organism are superoxide anion radical (O2-.), hydrogen peroxide (H2O2), hydroxyl radical (.OH), singlet oxygen (1O2) etc. A proper ratio between both production and breakdown of oxy-radicals is essential for the maintenance of a dynamic equilibrium of vital processes. The superoxide dismutases protect cells against toxic influence of the superoxide. In addition, some square-pyramidally pentacoordinated copper(II) complexes, derived from tridentate Schiff bases of the N-salicylideneaminoalcanoate type, show remarkable SOD-like activity. A selected set of complexes of this type have been tested: potassium [aqua-(N-salicylideneglutamato) cuprate] (L- and D,L-form), potassium [(isothiocyanato)-(N-salicylideneglycinato) cuprate], potassium [(isothiocyanato)-(N-salicylidene-D,L-alaninato) cuprate], potassium [(isothiocyanato)-(N-salicylidene-beta-alaninato) cuprate] and potassium [(isocyanato)-(N-salicylideneglycinato) cuprate]. Our results suggest that the copper complexes are not only antioxidants, but may also possess anti-inflammatory, cytostatic and radioprotective properties.

Synthesis, structural characterization, antiradical and antidiabetic activities of copper(II) and zinc(II) Schiff base complexes derived from salicylaldehyde and β-alanine

“…Calcd. for C 10 Method (b): The alternative method for obtaining large single crystals, suitable for X-ray structural analysis, was also used. The starting complex, i.e.…”

“…As for the extent of the studies of copper(II) Schiff base complexes derived from salicylaldehyde and amino acids, the first extensive observations were performed in the 1950s when the vitamin B6-like activities were described. Since then, a wide screening of biological activity was carried out and the SOD-mimic [8][9][10][11][12], radioprotective [8], antibacterial [13][14][15][16], antimycotic [13], fungistatic [10,13], antirheumatic [17], antipyretic and antidiabetic [18,19] activities were discovered and interactions with different biomolecules were described [20][21][22][23][24][25][26][27][28][29]. In contrast to a high number of papers dedicated to the studies of copper(II) complexes with Schiff bases derived from salicylaldehyde and amino acids, there are only a few works studying the structure of zinc(II) complexes [30].…”

“…aquabis(N-salicylidene-jO-b-alaninato-jN: jO 0 )dicopper(II) monohydrate (labelled as complex 1 in this work), attracted our attention due to its significant biological activity, i.e. SOD-mimic, radioprotective or antiarthritic [8][9][10]17]. Moreover, the molecular structure of this complex, as well as, its interesting magnetic properties were determined [31,32].…”

Crystal and Molecular Structure and Properties of Tetrasodium<br />[Bis { (µ-isothiocyanato-N,S)(N-salicylidene-β-alaninato) } dicuprate(II)] Dithiocyanate Tetrahydrate

“…3549 (1) 5213 (1) 3.29 Na (2) 6244 (3) 2673 (3) 4957 (1) 6.67 0 (4) 2939 (4) 2378 (2) 6366 (2) 3.44 0 (5) 1988 ( [11] used for its synthesis, showed dimeric structures. Their bridge systems, however, are quite different.…”

“…as models for the more complicated key intermediates in enzymatically catalyzed m eta bolic reactions of amino acids [1][2][3]. Some of them show remarkable antimicrobial activity [4], and superoxide dismutase like activities [5].…”