Design, synthesis and biological activity of cationic porphyrins bearing mixed 3-quinolyl and 4-pyridyl meso groups

Aim: To search for the potent telomerase inhibitors with structures of cationic porphyrins to improve the interactions between G-quadruplex and porphyrins by systematically varying the meso substituents. Methods: Porphyrins bearing mixed 3-quinolyl/4-pyridyl meso groups were synthesized using the Adler-Longo method by condensation of aldehydes with pyrrole, and then followed by methylation and ion exchange. The compounds were tested for the telomerase inhibitory activity and c-Myc inhibitory activity. Results: All compounds were found to be potent and approximately equivalent in terms of their ability to inhibit the action of telomerase in a cell-free assay. Compound 4 had the best inhibitory activity on c-Myc. Conclusion: Cationic porphyrins would be the potential anticancer candidates.