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 antiarthri tic drug, was prepared in highly pure form by one-step synthesis from NaAuCl4 and tma(3-) in aqueous solution. The reaction consisted of a r eduction 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 colum n and the contaminating NaCl by passing through a gel filtration colum n. The tma-Au(I) complex was also prepared by another reaction based o n ligand exchange of the intermediate complex AuCl(thiodiglycol) with tma(3-). It was purified using the anion-exchange resin and gel filtra tion columns. The target compound, finally isolated in 30% yield in hi ghly 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 bas ed on the [Naf] measurement in equilibrium state using a Na+-ion selec tive 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 polymerizati on degree, low in comparison with previously proposed data, was determ ined in the neutral aqueous solution without any other electrolytes un der 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 aqueou s solution. The properties of the oligomeric tma-Au(I) complex were co mpared with those of the previously reported complex and a commerciall y available sample, and also with those of the recently prepared, olig omeric tma-Ag(I) complex with antimicrobial activity.