Complex formation between D-lactobionate and bivalent metal ions. Studies in solution and in the solid state

Abstract

The equilibrium reactions between deprotonated D-lactobionic acid (4-O-β-D-galactopyranosyl-D-gluconic acid) and cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II), and mercury(II) have been studied by potentiometric and spectrophotometric methods in aqueous solution. All measurements have been carried out at a temperature of 20.0 ± 0.1 °C and at an ionic strength of 0.100 M (NaNO3) with the corresponding stability constants calculated by applying computational methods. The interactions between the proposed cations with deprotonated D-lactobionic acid were compared with those corresponding to D-gluconic acid. Compounds of type: Co(C12H21O12)2•2H2O•C2H5OH, Ni(C12H21O12)2•2H2O•C2H5OH, Cu(C12H21O12)2•2H2O•C2H5OH, Zn(C12H21O12)2•2H2O•C2H5OH, and Cd(C12H21O12)2•2H2O•0.5C2H5OH have been isolated. These metal–sugar salts were characterized by elemental, thermogravimetric, and susceptibility analyses and FT-IR, UV–visible absorption, diffuse reflectance, and 13C NMR spectroscopies. Keywords: D-lactobionate, metal complexes, equilibrium constants, potentiometry, solid state studies.

Hg(II)-coordination by sugar-acids: Role of the hydroxy groups

“…We propose the deprotonation of (6)) is near to that found for the Hg-sugar acid complexes where the involvement of hydroxide was proposed: L = lactobionic acid log b = À0.29 [21], L = D-gluconic acid log b = 0.09 [22], L = galactaric acid log b = À3.22(3) [23].…”

“…NMR analyses allow to propose the deprotonation of coordinated O-4 hydroxyl in GluA, while in GalA the precipitation of Hg(OH) 2 is observed, therefore [Hg(GalA)H À1 ] is associate to a mixed hydroxo species as often found in Hg-carbohydrate systems [21][22][23]. The coordination mode of GlNA resembles that of amino acids.…”

Complexation of Th(IV) and Eu(III) by α-isosaccharinic acid under alkaline conditions

“…The reasons for including protons in reactions (Eqs. (2) and (3)) are the hydrolysis of Th(IV), Eu(III) and Ca, and the observation that the co-ordination of polyhydroxy ligands with charged cations at alkaline pH is accompanied by deprotonation of the coordinating hydroxo groups [17][18][19][20][21][22]. The thermodynamic complexation constants (K and K Ca ) associated to Eqs.…”

Lactobionic acid: A high value-added lactose derivative for food and pharmaceutical applications

“…Pharmaceutical Enhancement of solubility of macrolide antibiotics such as erythromycin and clarithromycin Anti-aging and keratinizing ingredient of skin care cosmetics Calcium supplementation Metal-chelating agent in organ preservation solutions Ingredient in chlorhexidine-based disinfectant Bio-surfactant in its fatty acid derivatives forms Inducer for cellulase production by Trichoderma reesei Functional molecule in the synthesis of polymeric nanoparticles for liver-specific drug deliver (Ahamed & Vermette, 2008;Frutos et al, 1997;Green et al, 2009;Jain & Jain, 2010;Playne & Crittenden, 2009;Van Hecke et al, 2011) Food Acidulant with a sweet taste Filler in cheese production Firming agent Calcium carrier in functional drinks Reduction of souring and ripening time for the production of cheese and yogurt Enhancement of flavors Improvement of bitter or sour taste of foods Preservation of aroma freshness Preparation of dairy products with reduced lactose content (Gerling, 1998;Merrill & Singh, 2009;Nakano et al, 2010;Nordkvist et al, 2007;Playne & Crittenden, 2009) Chemical Ion sequestrant in detergent solutions Biodegradable cobuilder in washing powder Anti-corrosive coatings Chiral selector for enantiomeric separation of basic drugs in capillary electrophoresis (clarithromycin lactobionate) Reactant for synthetic amides (Gerling, 1998;Yu et al, 2011) Nanotechnology Part of biocompatible scaffolds for tissue engineering Part of nanoplatforms for new bioimaging applications Ingredient of galactose-conjugated fluorescent nanoparticles for immunofluorescence assays (Chung et al, 2002;Kekkonen et al, 2009;Peng et al, 2007) volunteers periodically over two weeks (Tasic-Kostov et al, 2010). LBA could increase the synthesis of glycosaminoglycans in the skin, and it has been shown to enhance cell turnover in vitro (Briden & Green, 2005).…”