Interaction of Copper(II) Ions with Pectin in Solutions

The search for new detoxifiers that effectively bind toxic metals and retain vital metals in the human body is currently an urgent problem in pharmacy. Pectins, natural polysaccharides capable of distribution even in poorly accessible biological tissues that enhance the neutralizing functions of the liver and accelerate the evacuation of intestinal contents, are promising compounds in this regard. The purpose of the study is experimental substantiation of the ability to use beet pectin (BP) to bind toxic metal ions [e.g., Cu(II)] by determining the composition and stability of the soluble reaction products (CuBP) using spectrophotometric and potentiometric analytical methods. The composition and stability of CuBP were studied using the method of molar ratios (saturation method), limited logarithmic (Bent(French) method, least-squares methods, and the equilibrium shift method. Formation of only one product containing 2 mol of BP monomer per 1 mol of Cu(II) was established by the study. A relatively high stability of the BP complex with Cu(II) (logβ 6.97 – 7.69) that did not exceed those for biological complexes of amino acids, nucleotides, and enzymes (logβ 14.4 – 16.0) and the popular sodium EDTA complex (logβ 18.8) was revealed. However, the BP complex with biogenic metals (logβ 1.24 – 2.35) is much less stable than biological complexes of amino acids, nucleotides, and enzymes (logβ 4.5 – 6.1) and sodium EDTA(logβ 10.7 – 13.79). The relatively high efficiency of BP binding of toxic metal ions together with the low selectivity for biogenic metals considering the specific biological properties define the advantages of BP as an antidote compared to known detoxifiers.