title: Structural determination of 5'-OH alpha-ribofuranoside modified cobalamins via 13C and DEPT NMR.
abstract: A protocol for the rapid NMR characterization of cobalamin (vitamin B(12)) analogues with 5'-hydroxy-alpha-ribofuranoside modification is reported. The structure of cyanocobalamin in DMSO-d(6) has been assigned using COSY, NOESY, HSQC, and HMBC NMR methods. The robust precision of (13)C NMR assignments in DMSO-d(6) allows for the rapid structural determination of 5'-hydroxy-alpha-ribofuranosyl cyanocobalamin derivatives with solely 1-D (13)C and DEPT NMR spectra and only 10 mg of derivatized cobalamin. Using this method, the (13)C NMR resonances of four cobalamin analogues were determined with the most significant variance of (13)C chemical shifts occurring in the alpha-ribofuranoside ring. In DMSO-d(6), cobalamin concentrations greater than 30 mM can be achieved for an improved signal-to-noise ratio.
authors.affiliation: Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Horton
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Bagnato
authors.forename: Charles B
authors.initials: CB
authors.lastname: Grissom
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis; D004121:Dimethyl Sulfoxide; D005456:Fluorescent Dyes / Q000138:chemical synthesis; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D019275:Radiopharmaceuticals / Q000138:chemical synthesis; D014805:Vitamin B 12 / Q000031:analogs & derivatives* / Q000138:chemical synthesis*
chemical_list: D000970:Antineoplastic Agents; D005456:Fluorescent Dyes; D019275:Radiopharmaceuticals; D014805:Vitamin B 12; D004121:Dimethyl Sulfoxide