METAL-COMPLEXES OF POLYMERS WITH AMINO-ACID-RESIDUES - FORMATION, STABILITY AND CONTROLLED BIOLOGICAL-ACTIVITY

Copolymers of N-vinylpyrrolidone and allyl glycidyl ether, modified in the side chain by residues of glycine, β-alanine, γ-aminobutyric acid and ε{lunate}-aminocaproic acid, have been synthesized. The structure and stability of the metal complexes of the copolymers have been investigated by ESR spectroscopy and potentiometric titration methods. It has been found that copolymers with glycine and β-alanine residues co-ordinate metal ions through the oxygen and nitrogen atoms of the amino acid residues; copolymers with γ-aminobutyric and ε{lunate}-aminocaproic acid residues form metal carboxylate complexes. The stability of the polymer-metal complexes depends on the nature of the amino acid residue and decreases in the following order: glycine >; β-alanine >;γ-aminobutyric acid >;ε{lunate}-aminocaproic acid derivatives. The acute toxicity and haemopoiesis-stimulating activity of copolymers and their complexes with cobalt have been taken as evidence of the biological activity of the polymer-metal complexes. It has been shown that the biological properties of polymermetal complexes can be controlled by regulating their stability and structure. Thus, the use of polymers as ligands for creation of polymer-metal complexes is a fruitful means of producing new biologically active compounds affording controlled release of bioactive metals. © 1990.