SIMULTANEOUS REPLACEMENTS OF TRIETHYL PHOSPHINE AND TETRAACETYL THIOGLUCOSE LIGANDS FROM AURANOFIN (AN ANTIARTHRITIC DRUG) WITH SELENOCYANATE - C-13 AND P-31 NMR-STUDIES

The interaction of SeCN- with a new gold-based antiarthritic drug aura nofin (Et(3)PAuSATg, where SATg(-) = ,6-tetra-O-acetyl-1-thio-beta-D-g lucopyranosato-S) in aqueous methanol has been studied by C-13 and P-3 1 NMR spectroscopy. It is observed that SeCN- releases both ligands (i .e., SATg(-) and Et3P) to form [ATgS-Au-CN](-) and [Et3P-Au-SeCN]. The se newly generated species undergo further disproportionation and deco mposition to generate species such as [(Et3P)(2)Au](+), [Au(CN)(2)](-) , Et3PO and metallic selenium. The formation of [(Et3P)(2)Au](+) and [ Au(CN)(2)](-) is found to be much faster for Et3PAuNO3 than for Et(3)P AuSATg when reacted with SeCN-. Exchange between unlabelled CN- of Au( CN)(2)(-) and labelled (SeCN-)-C-13 was observed without selenium bein g precipitated from (SeCN-)-C-13.