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

Abstract

The interaction of SeCN^? with a new gold-based antiarthritic drug auranofin (Et₃PAuSATg, where SATg^? = 2, 3, 4, 6-tetra-O-acetyl-l-thio-β-D-glucopyranosato-S) in aqueous methanol has been studied by ¹³C and ³¹P NMR spectroscopy. It is observed that SeCN^?releases bom ligands (i. e., SATg^? and Et₃P) to form ATgS-Au-CN]^? and Et₃P-Au-SeCN]. These newly generated species undergo further disproportionation and decomposition to generate species such as (Et₃P)₂Au]⁺, Au(CN)₂]^?, Et₃PO and metallic selenium. The formation of (Et₃P)₂Au]⁺ and Au(CN)₂]^? is found to be much faster for Et₃PAuNO₃ than for Et₃PAuSATg when reacted wim SeCN^?. Exchange between unlabelled CN^? of Au(CN)₂ ^? and labelled Se¹³CN^? was observed without selenium being precipitated from Se¹³CN^?.