title: Comparative (13)C and (31)P NMR studies of the ligand exchange reactions of auranofin with ergothionine, imidazolidine-2-thione and diazinane-2-thione.
abstract: The interaction of auranofin (Et(3)PAuSATg) with ergothionine (ErS), imidazolidine-2-thione (Imt) and diazinane-2-thione (Diaz) has been studied using (13)C and (31)P NMR spectroscopy. It is observed that these thiones are able to replace both Et(3)P and SATg(-) ligands simultaneously from gold(I) in auranofin forming >C [double bond] S-Au-SATg and [Et(3)P-Au-S [double bond] C<](+) type complexes. The displaced SATg(-) is oxidized to its disulfide (SATg)(2). However, some of the displaced Et(3)P is oxidized to Et(3)PO while the remaining reacts with thiones to form Et(3)P-S [double bond] C< species characterized by delta (31)P NMR of 1.0-1.5 ppm. The Et(3)PO resonance appeared in the 31P NMR spectrum, after 10 days of the addition of ErS, after 19 days of the addition of Imt and after 6 days of the addition of Diaz, to auranofin solution showing that the thiones react with auranofin very slowly.
authors.affiliation: Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia. aisab@kfupm.sa
authors.forename: Anvarhusein A
authors.initials: AA
authors.lastname: Isab
authors.forename: Saeed
authors.initials: S
authors.lastname: Ahmad
mesh_terms: D018501:Antirheumatic Agents / Q000737:chemistry* / Q000378:metabolism; D001310:Auranofin / Q000737:chemistry* / Q000378:metabolism; D002247:Carbon Isotopes; D004880:Ergothioneine / Q000737:chemistry / Q000378:metabolism; D005031:Ethylenethiourea / Q000737:chemistry / Q000378:metabolism; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D010720:Phosphines; D010759:Phosphorus Isotopes; D013871:Thiones / Q000737:chemistry* / Q000378:metabolism
chemical_list: D018501:Antirheumatic Agents; D002247:Carbon Isotopes; D006573:Heterocyclic Compounds, 1-Ring; D007093:Imidazoles; D008024:Ligands; D010720:Phosphines; D010759:Phosphorus Isotopes; D013871:Thiones; C447643:diazinane-2-thione; D005031:Ethylenethiourea; D001310:Auranofin; D004880:Ergothioneine