Features of Cobalt(II) Complexes Formation with Pharmacophore-Modified Apple Pectin

Complexation of cobalt(II) chloride with apple pectin modified with organic pharmacophores (nicotinic, salicylic, 5-aminosalicylic, or anthranilic acid) has been studied by spectral methods. Molar composition, stability constants of the complexes, and pH range of their existence have been determined; standard thermodynamic characteristics (ΔH°, ΔG°, ΔS°) of the complexes formation have been calculated. it has been shown that cobalt(II) ions form complexes of different stability with pharmacophore-containing pectins, which may be due to the unequal affinity of the metal ions to the donor groups of the monomer unit of the polysaccharide matrices.