4′-Phenyl-2,2′:6′,2"-terpyridine Derivatives Containing 1-Substituted-2,3-Triazole Ring: Synthesis, Characterization and Anticancer Activity

Terpyridine moiety is known for chelating and interesting physicochemical properties enabling some applications. Its biological activity, particularly anticancer potency is not well studied. Herein we present six 4'-(1-substituted-2,3-triazol-4-yl)phenyl-2,2':6',2"-terpyridine derivatives with glycidyl, cyclohexylmethyl, benzyl, 4-tert-butylbenzyl, pentafluorobenzyl, and 2,6-dichlorobenzyl groups which were obtained via Cu(I)-catalysed 1,3-dipolar cycloaddition reaction. The photophysical such as optical (absorption and photoluminescence spectra, quantum yields and lifetimes) and thermal (by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)) properties were examined. In addition, theoretical studies (DFT and TD-DFT) were performed to provide a deeper understanding of the experimental results. In vitro studies on the obtained novel structures were conducted with selected series of cell lines to check their bioactivity and toxicity. The most active compound reached a nanomolar level with good selectivity index better than doxorubicin. Mechanism of action for these terpyridines was also investigated which suggest intercalation of DNA as a trigger of cell death.