Investigation on DNA binding and photo-cleavage properties of water-soluble porphyrin and metalloporphyrins

A water-soluble porphyrin, tetrakis[4-(trimethylammonium)phenyllporphyrin (TAPP), and its metal complexes with Zn(II), (ZnTAPP), have been synthesized and characterized by elemental Analyses and u.v.-vis. spectra. The binding of the two complexes with calf thymus DNA has been investigated by absorption spectra, luminescence titrations, and viscosity measurements. The changes of the u.v.-vis. absorption spectra during the titration of these porphyrins with calf thymus DNA revealed a large bathochromic shift (upto 8- 12 nm) and a hypochromicity of the porphyrins soret bands. The intensity of the fluorescence spectra of these porphyrins was enhanced. The cytotoxicity of the series of porphyrins TAPP and MTAPP [M = Zn(II), Cu(II), Fe(III), Co(III), Ni(II), Mn(III)] complexes was determined for Madin-Darby Canine Kindney (MDCK) cells and Vero cells with the method of cell culture, and were evaluated as anti-virus activity for influenza virus type A (H3N2), B and Herpes simplex virus type-1 (HSV-1, strain SM44), type-2 (HSV-2, strain 333) in vitro. Among the complexes evaluated, inhibited viral cytopathogenicity at lower concentrations that were found cytotoxic for the MDCK cells. Differences were observed in the 50% effective doses (based on inhibition of viral cytopathogenicity) of these complexes for a number of influenza viruses type A, B, and HSV-1, HSV-2 strains. It was found that CoTAPP displayed good inhibitory action against the virus in vitro.