Über die Eisenanaloga von Cobalamin und Cobyrsäure* About the Iron Analogues of Cobalamin and Cobyric Acid

Vitamin B12, Cobyric Acid, Fe(III)Cobalamin, Fe(III)Cobyric Acid, Iron-B12-Analogues, UV/VIS-, NMR-, ESR-Spectra The reaction of hydrogenocobalamin or hydrogenocobyric acid (both isolated from Chromatium vinosum) with iron(III) acetate and iron powder in acetic acid under N 2 at 80 °C leads to the incorporation of iron into these cobalt-free corrinoids. The products, Fe(III)cobalamin and Fe(ni)cobyric acid, were separated by means of a column of Amberlite XAD-2. They have the electrophoretic mobility of the corresponding cobalt-corrinoids. The brown aqua-forms react with cyanide, rhodanide and azide, and can be reduced by means of NaBH4 to the green Fe(I) forms. The new compounds were analyzed and characterized by means o f elemental analysis, paper chromatography, electrophoresis and spectra (UV/VIS, NMR, ESR).