title: New dinuclear cobalt(II) and zinc(II) complexes of a carboxylate-rich dinucleating ligand: synthesis, structure, spectroscopic characterization, and their interactions with sugars.
abstract: Sugar-metal ion interactions in aqueous medium are involved in many biochemical processes such as the transport and storage of metals, the function and regulation of sugar-metabolizing metalloenzymes, the mechanism of action of metal-containing pharmaceuticals, and toxic metal metabolism. To understand such interactions we synthesized and fully characterized two new dinuclear cobalt(II) and zinc(II) complexes as carbohydrate binding models for xylose/glucose isomerases (XGI). Synthesis of the dicobalt complex, Na3[Co2(ccdp)(μ-HCO2)]BF4·9H2O·2CH3OH (1), was performed in methanol with stoichiometric amounts of Co(BF4)2·6H2O and the dinucleating ligand, H5ccdp (H5ccdp = N,N'-bis[2-carboxybenzomethyl]-N,N'-bis[carboxymethyl]-1,3-diaminopropan-2-ol), in the presence of NaOH at ambient temperature in an argon glovebox. Similarly, the dizinc complex, [NMe4]2[Zn2(ccdp)(μ-OAc)]·CH3OH (2), was synthesized from Zn(OAc)2·2H2O and H5ccdp in the presence of NMe4OH at ambient temperature in methanol. Binding of the complexes with carbohydrates was investigated under different reaction conditions. In aqueous alkaline media, complexes 1 and 2 showed chelating ability towards the biologically important sugars, d-glucose and d-xylose, and a polyalcohol enzyme inhibitor (xylitol). In solution, each complex forms a 1:1 complex-substrate bound product with specific binding constant values. Synthesis, characterization details, and substrate binding using spectroscopic techniques and single-crystal X-ray diffraction are reported.
authors.affiliation: Department of Chemistry, University of Kalyani , Kalyani, West Bengal 741235, India.
authors.forename: Manindranath
authors.initials: M
authors.lastname: Bera
authors.forename: Ashley B S
authors.initials: AB
authors.lastname: Curtiss
authors.forename: Ghezai T
authors.initials: GT
authors.lastname: Musie
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Powell
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D002241:Carbohydrates; D002264:Carboxylic Acids; D008024:Ligands; D009942:Organometallic Compounds; D003035:Cobalt; D003300:Copper