Synthesis, characterization and applications of copper(II) complexes with Schiff bases derived from chitooligosaccharide and iodosubstituted salicylaldehyde

Cu(II) complexes with Schiff bases derived from chitooligosaccharide and iodosubstituted salicylaldehyde (ISCOS) were synthesized and characterized by EA, ICP, FTIR and SEM. The Cu(II) was coordinated by the imino N atoms and phenolic hydroxyl O atoms from I-SCOS. The antimicrobial activities of I-SCOS and their Cu(II) complexes were investigated against Enterobacter cloacae, Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus saprophyticus. The results indicated that the introduction of the iodosubstituted and the imine groups of Schiff bases increased the antimicrobial activity of I-SCOS and exhibited a superposition effect of molecular structure. The coordination interaction between I-SCOS and Cu(II) further enhanced the antimicrobial activities. The scavenging superoxide anion radical activity of I-SCOS derivatives was estimated by using NBT/VB2/methionine superoxide anion radical producing system. When the concentration of the complexes was more than 0.3 mg/mL, their antioxidant activity was higher than that of I-SCOS.