The role of side chain of amino acid on performance of their conjugates with carboxymethyl cellulose and their Pd(II) complexes as bioactive agents

Abstract

Set of amino acid conjugates with carboxymethyl cellulose (CMC) were synthesized as ligands for complexation with Pd(II) ions. In this respect, different side chain of amino acids (Methonine, Lycine, Leucine and Phenyl alanine) are reacted with CMC via condensation reaction in the absence of a solvent. The formed conjugates and their Pd(II) complexes are characterized by TGA, FTIR, elemental, magnetism, conductivity analyses of conjugates and their Pd(II) complexes, as well as their behavior as anti-cancer for colon cell and anti-oxidant are assessed. The data evidence the complexation of conjugate with Pd (II) ions occurs in molar ratio 2:1, through carboxylate groups and aliphatic ether included in the CMC. The formed complexes are diamagnetic and square planar geometry. The greatest inhibition in human tumor cell lines-HCT116 colon cancer cell proliferation is observed in the case of phenyl alanine (92.6%) and methionine (53.6%) conjugates at a dose of 100 µg/mL. The IC₅₀ of these conjugates are 51.2 µg/mL and 90.3 µg/mL, respectively. Both Pd-free conjugates and their complexes have antioxidant property (IC₅₀ ∼ 58–67%). The greatest anti-oxidant behavior is noticed for Lycine conjugate-Pd complex, this complex has anti-tumor activity that reaches 84% at a dose of 100 µg/mL.

Graphical Abstract

Keywords:

• Amino acid conjugates
• anti-cancer active CMC
• anti-oxidant active CMC
• new bioactive cellulose derivatives
• Pd-complexes