title: Cobalamin reduction by dithionite. Evidence for the formation of a six-coordinate cobalamin(II) complex.
abstract: Evidence for the formation of a unique, six-coordinate cobalamin(II) complex with the anion-radical SO(2)(-) during the reduction of aquacobalamin(III) by sodium dithionite, was obtained from spectrophotometric and EPR measurements. The pK(a) value of the weakly coordinated dimethylbenzimidazole group was found to be 4.8 ± 0.1 at 25 °C.
authors: State University of Chemistry and Technology, Ivanovo, Russia.
authors: Denis S
authors: DS
authors: Salnikov
authors: Radu
authors: R
authors: Silaghi-Dumitrescu
authors: Sergei V
authors: SV
authors: Makarov
authors: Rudi
authors: R
authors: van Eldik
authors: Gerry R
authors: GR
authors: Boss
mesh_terms: D056831:Coordination Complexes / Q000138:chemical synthesis* / Q000737:chemistry; D004227:Dithionite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D014805:Vitamin B 12 / Q000737:chemistry*
chemical_list: D056831:Coordination Complexes; D004227:Dithionite; D014805:Vitamin B 12