SYNTHESIS AND CHARACTERIZATION OF HIGHLY PURE FORM OF SODIUM-SALT OF ANIONIC, THIOMALATOGOLD(I) COMPLEX WITH ANTIARTHRITIC ACTIVITY - ANALOGS OF ANIONIC, THIOMALATOSILVER(I) COMPLEX WITH ANTIMICROBIAL ACTIVITY

Sodium salt of anionic Au(I) complex with a trianion of thiomalic acid tma(3-) (H(3)tma=HOOCCH(SH)CH2COOH), known as an effective antiarthritic drug, was prepared in highly pure form by one-step synthesis from NaAuCl4 and tma(3-) in aqueous solution. The reaction consisted of a reduction of Au(III) by tma(3-) and the following complexation of Au(I) with tma(3-) ligand. The disulfide species of tma(3-) formed by this reduction was removed by passing through an anion-exchange resin column and the contaminating NaCl by passing through a gel filtration column. The tma-Au(I) complex was also prepared by another reaction based on ligand exchange of the intermediate complex AuCl(thiodiglycol) with tma(3-). It was purified using the anion-exchange resin and gel filtration columns. The target compound, finally isolated in 30% yield in highly pure form, has been characterized by complete elemental analyses, TG/DTA, FT-IR, H-1 and C-13 NMR spectroscopies, and molecular weight was determined in aqueous solution by molmass measurement based on the cryoscopic method combined with dissociation degree determination based on the [Naf] measurement in equilibrium state using a Na+-ion selective electrode. This Au(I) complex was an oligomer with a formula of {Na-2[Au(tma)]. 1.75H(2)O}(n) (n=3-10; MW=1260-4220). This polymerization degree, low in comparison with previously proposed data, was determined in the neutral aqueous solution without any other electrolytes under the concentration range C-Na=0.914-182.9 mmol dm(-3). The tma-Au(I) complex exists in an oligomeric form both in the solid and in aqueous solution. The properties of the oligomeric tma-Au(I) complex were compared with those of the previously reported complex and a commercially available sample, and also with those of the recently prepared, oligomeric tma-Ag(I) complex with antimicrobial activity.