Synthesis, characterization, antimicrobial and anticancer evaluation of N-aryl aminochitosan

Various pyrazole/chitosan Schiff bases derivatives (3a-f) were synthesized through the reaction of pyrazole derivatives (2a-f) with chitosan (1). The produced derivatives were characterized using FT-IR, Elemental analysis and TGA. The antimicrobial activities of Schiff bases were tested against Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus), Gram-negative bacterium (Escherichia coli). Results indicated a good inhibitory activity for compound (3b) when tested against (Bacillus cereus) and , however, (3f) gave a pronounced inhibitory activity against (Staphylococcus aureus). All the synthesized derivatives have no inhibitory activity against Gram-negative bacteria. Pyrazole/chitosan Schiff bases were reduced by sodium boron hydride giving aminochitosan derivatives that were characterized by FT-IR. The antimicrobial activity of the aminochitosan derivatives were evaluated against some Gram-positive bacteria (Staphylococcus epidermidis) and Gram-negative bacteria (Pseudomonas aeruginosa and Proteus mirabilis). Results confirmed that compound (4f) showed high antibacterial activity against (Pseudomonas aeruginosa) was recorded 21 +/- 1.1 mm inhibition zone and it was exhibited a medium antibacterial activity against (Proteus mirabilis). However, compound (4a) showed a high antibacterial activity against Gram-positive bacteria (Staphylococcus epidermis) that recorded inhibition zone of 17* +/- 0.8 mm. From the results, it was showed that the modification of pyrazole/chitosan Schiff bases by reduction process increased their biological activity as antimicrobial and anticancer agents against Gram-negative bacteria (Pseudomonas aeruginosa and Proteus mirabilis). Aminochitosan derivatives were tested for their cytotoxicity activity against Human Breast Adenocarcinoma Cells (MCF-7). The compound (4e) has the highest anticancer activity with IC50 136 mu g/ml, which might be due to the presence of thiophene nucleus.

Automated summary

Schiff bases and aminochitosan derivatives were synthesized and tested for their antimicrobial activity. Compound (3b) showed good inhibitory activity against Bacillus cereus, while (3f) exhibited pronounced inhibitory activity against Staphylococcus aureus. Aminochitosan derivatives demonstrated medium to high antibacterial activity against Pseudomonas aeruginosa and Proteus mirabilis. The modification of pyrazole/chitosan Schiff bases increased their biological activity as antimicrobial and anticancer agents.