Oxidation of biologically relevant chalcogenones and their Cu(I) complexes: insight into selenium and sulfur antioxidant activity.
Hydroxyl radical damage to DNA causes disease, and sulfur and selenium antioxidant coordination to hydroxyl-radical-generating Cu(+) is one mechanism for their observed DNA damage prevention. To determine how copper binding results in antioxidant activity, biologically relevant selone and thione ligands and Cu(+) complexes of the formula [Tpm*Cu(L)](+) [Tpm* = tris(3,5-dimethylpyrazolyl)methane; L = N,N'-dimethylimidazole selone or thione] were treated with H2O2 and the products analyzed by (1)H, (13)C{(1)H}, and (77)Se{(1)H} NMR spectroscopy, mass spectrometry, and X-ray crystallography. Upon H2O2 treatment, selone and thione binding to Cu(+) prevents oxidation to Cu(2+); instead, the chalcogenone ligand is oxidized. Thus, copper coordination by sulfur and selenium compounds can provide targeted sacrificial antioxidant activity.
Department of Chemistry, Clemson University , Clemson, South Carolina 29634-0973, United States.
Martin M
MM
Kimani
Craig A
CA
Bayse
Bradley S
BS
Stadelman
Julia L
JL
Brumaghim
D000975:Antioxidants / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006861:Hydrogen Peroxide / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D012643:Selenium / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*
D000975:Antioxidants; D009942:Organometallic Compounds; D013455:Sulfur; D003300:Copper; D006861:Hydrogen Peroxide; D012643:Selenium