A(3)B Porphyrins Bearing Thienyl/Pyridyl Moieties Obtained via Scrambling: Characterization, DNA interaction and Anticancer Studies

Condensation of 3-pyridine carboxaldehyde with 2/3-thienyl dipyrromethanes in presence of acid catalyst gives 5-(3'-pyridyl)-10,15,20-tri(2/3-thienyl)porphyrins (S1a and S2a) due to scrambling along with the expected trans-porphyrins. The corresponding copper(II) and zinc(II) porphyrins were also synthesized. Moreover, to study their biological properties their cationic derivatives were obtained. All the complexes were characterized by UV-Vis, fluorescence, NMR spectroscopy, mass spectrometry and cyclic voltammetry. The cationic porphyrins bind with DNA non-intercalatively; show singlet oxygen mediated photocleavage; phototoxic to A549 lung cancer cells through apoptotic pathway.