Novel branched Heteroaromatic Pyrazole-based Polyazomethines as anticancer agents

A series of novel pyrazole-based polyazomethines incorporating different heteroaromatic moieties was synthesized via the polycondensation of diaminopyrazole with terephthalaldehyde, 10-octylphenothiazine-3,7-dicarbaldehyde, and 9-hexylcarbazole-3,6-dicarbaldehyde. The polymers were characterized using FT-IR, XRD, SEM, GPC, and TGA/DTG techniques. FT-IR spectroscopy confirmed successful polymerization in the presence of imine linkages. XRD revealed the crystalline nature of the polymers, whereas SEM showed distinct morphological differences between PAT and PPTz-C8. GPC analysis indicated molecular weights ranging from 27,800 Da to 55,800 Da, with PPTz-C8 exhibiting the highest molecular weight and viscosity. TGA/DTG demonstrated the thermal stability of the polymers, with PCz-C6 exhibiting the highest thermal stability. The antimicrobial activities of the polymers were evaluated against gram-negative and gram-positive bacteria as well as against fungi. PPTz-C8 and PCz-C6 displayed the most potent antibacterial activity against E. coli. The anticancer activity of the polymers was assessed against human colorectal cancer (HCT116) cells, with the monomer and PAT exhibiting the highest potency. The incorporation of different heteroaromatic moieties significantly influenced the properties and biological activities of polyazomethines, making them promising candidates for various applications in materials science and medicinal chemistry.