Synthesis of Mn(II) Complexes-Carboxymethyl Chitosan Schiff Base Salicylaldehyde and Antibacterial Activity

Abstract

The development of compounds with a better antibacterial activity is highly needed. One way to achieve this is by modifying the structure of the compound using chitosan as a starting material, because of its abundant natural source in Indonesia, its biodegradable properties, and its structure where free amines are present. This study aims to obtain  Mn(II) -Carboxymethyl Chitosan Schiff Base-Salicylaldehyde complex to increase its antibacterial activity against Staphylococcus aureus (Gram positive) and Escherichia coli (Gram negative). Schiff Base carboxymethyl chitosan-salicylaldehyde was synthesized from carboxymethyl chitosan with salicylaldehyde. Next, the Schiff Base Carboxymethyl Chitosan-Salicylaldehyde was complexed with MnCl2.4H2O and then characterized by FTIR, UV-Vis Spectrophotometer, and AAS and tested for antibacterial activity with the disc diffusion method against Staphylococcus aureus and Escherichia coli. The product of Carboxymethyl Chitosan Schiff Base-salicylaldehyde is a brownish yellow solid with a yield of 64% (w/w) and has antibacterial activity against Staphylococcus aureus (clear zone diameter 11 mm) and Escherichia coli (clear zone diameter 13 mm). The product of Mn(II) Complexes-Carboxymethyl Chitosan Schiff Base-salicylaldehyde is a black solid with a yield of 59% (w/w) and has antibacterial activity against Staphylococcus aureus (clear zone diameter 13 mm) and Escherichia coli (clear zone diameter 17 mm).