Synthesis and comprehensive characterization with anticancer activity assessment of salicylaldehyde and 2-acetylphenol based chitosan thiosemicarbazones and their copper(II) complexes

• Published in: Carbohydrate polymer technologies and applications 2024-06, Vol.7, p.100469, Article 100469
• Main Authors: Adhikari, Hari Sharan, Garai, Aditya, Khanal, Chetana, Yadav, Paras Nath
• Format: Article
• Language: English
• Subjects: 2-Acetyl phenol; Anticancer activity; Chitosan; Chitosan thiosemicarbazones; Copper(II) chitosan thiosemicarbazones; Functionalization; Salicylaldehyde
• ISSN: 2666-8939; 2666-8939
• DOI: 10.1016/j.carpta.2024.100469

•Chitosan tailoring via the involvement of amino group at C2 position of the pyranose ring was utilized to get chitosan functionalized salicylaldehyde and 2-acetylphenol-based thiosemicarbazones, and the corresponding copper(II) complexes were synthesized. The structural elucidation of the compounds was made by comprehensive characterization by spectroscopic and analytical ways.•The ONS tridentate ligand behavior was shown by both the low molecular weight (Mw) chitosan oligosaccharide (CS) (Mw < 3000 Da, degree of deacetylation (DDA) = 87 %) and the crab shell chitosan (CCS) (Mw = 350 k Da, DDA= 67 %) functionalized thiosemicarbazones towards the formation of the square planar copper(II) complexes in which a chloride ion as an additional ligand satisfied the co-ordination sphere.•All the derivatives were thermally stable till the commencement of chitosan backbone disruption at 200 °C. The chitosan functionalized thiosemicarbazones showed partial grafting of thiosemicarbazone moiety on to chitosan, with modification in native chitosan crystallinity.•The MTT assay profiles showed an enhancement in the in vitro activity of native chitosan against MDCK and MCF-7 cancer cell lines upon its functionalization as chitosan thiosemicarbazones, and activity was further enhanced upon the formation of copper(II) chitosan thiosemicarbazones.•Both the chitosan oligosaccharide and high mw crab shell chitosan, the corresponding chitosan-functionalized salicylaldehyde based thiosemicarbazones, and their copper(II) chitosan thiosemicarbazone complexes showed relatively a lower toxicity against the mouse embryonic normal fibroblast NIH3T3 cells up to 600 µg mL−1. Functionalization of chitosan as salicylaldehyde and 2-acetylphenol-based chitosan thiosemicarbazone involving amino group at C2 position of pyranose ring was confirmed by comprehensive characterization by spectroscopic and analytical ways. Both the low molecular weight (Mw) chitosan oligosaccharide (CS) (Mw < 3000 Da, degree of deacetylation (DDA) = 87 %) and the crab shell chitosan (CCS) (Mw = 350 kDa, DDA = 67 %) functionalized thiosemicarbazones behaved as ONS tridentate ligand to form the square planar copper(II) complexes with a chloride ion as an additional ligand to satisfy the co-ordination sphere. All the derivatives were found thermally stable till the commencement of chitosan backbone disruption at 200 °C. The MTT assay profiles showed a conspicuous enhancement in the in vitro antitumorigenic and anticanc