Synthesis, characterization, and antimicrobial activity of novel N-acetyl,N’-chitosanacetohydrazide and its metal complexes

A new modified chitosan derivative (N-acetyl,N’-chitosanacetohydrazide, ACsAH) and its cobalt(II), nickel(II), manganese(II), and copper(II) complexes were successfully prepared. Their structures were proven using elemental analysis, FTIR, 1H-NMR and electronic spectroscopy, magnetic moment, and molar conductance. An octahedral stereochemistry for all the synthesized ACsAH–metal complexes was proposed. Their activity against the tested microbes can be arranged as follows: ACsAH–Mn(II) complex > ACsAH–Co(II) complex > ACsAH–Ni(II) complex > ACsAH–Cu(II) complex > ACsAH > chitosan. The ACsAH–Mn(II) complex exhibited a greater potency in inhibition of the growth of some of the tested microbes than that of the used standard drugs.