Preparation and Anti-Inflammatory Activity of Selected Aqua(aryloxyacetato)zinc(II)Complexes

Overview

Mononuclear aqua(aryloxyacetato)zinc(II) complexes of the composition [Zn(H2O)2(ROCH2COO)2](R = phenyl, o-, m-, p-tolyl) were prepared as potential anti-inflammatory agents. The results ofelemental analysis and parameters of IR spectra allow to classify the above-mentioned compoundsto the group of carboxylatozinc(II) complexes with a distorted octahedral structure. They wereassayed in rat paw carrageenan-induced edema and antiedematous effects were compared to thoseof free acids. Salicylic acid and its zinc(II) and copper(II) salts were used as the standards ofcomparison. All compounds were administered i.p. in a single dose of 50 mmol/kg body weight(calculated for the carboxylate fragment). In general, the zinc(II) complexes tested were clearly moreeffective (expressed as a mean edema reduction of 58 – 70 – 68 – 59 %), including zinc(II) salicylatedihydrate (64 %), than the uncomplexed acids (37 – 26 – 50 – 48 %). Copper(II) salicylate tetrahyd-rate (60 %) and salicylic acid (57 %) exhibited comparable effects under the same conditions. Theobserved activities of the complexes are discussed in relation to their structures as well as to thecoordination-chemical properties of the acidoligands under study.

Key words:
zinc(II) complexes – rat paw carrageenan-induced edema – anti-inflammatoryactivity