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β-tetra (aminophenoxy) sulfonic substituted zinc phthalocyanines (SNZnPc), a novel amphiphilic zinc phthalocyanine (Pc), was synthesized. The photophysical, photochemical, and photobiology properties were studied. Results indicated that the synthesized SNZnPc has good amphiphilic property and high reactive oxygen species (ROSs) generation ability. Furthermore, SNZnPc has strong affinity to calf thymus DNA (CT-DNA) through intercalation ways and can effectively cleavage CT-DNA after irradiation by light with appropriate wavelength. [ABSTRACT FROM AUTHOR]

The interaction of UCPs with CT DNA are studied in detail by zeta potential, Energy dispersive spectrometer (EDS) spectroscopy, Thermogravimetric (TGA) analysis, DNA melting determination and various spectroscopic techniques including Ultraviolet–Visible (UV–Vis) absorption, fluorescence, circular dichroism (CD), Fourier transform infrared (FTIR) and Raman spectroscopy. The results indicate that CT DNA can assemble on the surface of UCPs mainly by relative stronger hydrophobic force and electrostatic binding, and the predominant interaction site is the deoxyribosyl phosphate backbone of CT DNA. Moreover, after interacting with UCPs, the double helix structure of DNA is undamaged. [ABSTRACT FROM AUTHOR]

Highlights: [•] PG intercalated into the DNA helix. [•] The binding of PG and ct-DNA are partial intercalation mode. [•] Van der Waals forces are mainly between PG and ct-DNA in the present of EB. [•] The interaction follows the static quenching mechanism. [Copyright &y& Elsevier]

Abstract: A porphyrin meso-tetrakis{[4-(1-pyridyl)propoxy]phenyl}porphyrin (TPyPP) and its Ni complex (TPyPP(Ni)) have been synthesized and characterized by 1H NMR, UV–vis spectra. The interaction of two porphyrins with calf thymus-DNA (CT-DNA) has been explored by UV–vis, fluorescence and circular dichroic spectroscopy and viscosity measurements. The results suggest that these porphyrins can bind to DNA by the same binding mode. TPyPP outside binds by self-stack with DNA both at low drug load r (=[porphyrin]/[DNA]) and high drug load. Though TPyPP(Ni) has center metal nickel, binding mode with DNA has little difference compared with TPyPP, dominating out-binding mode with different direction along DNA. The binding constants of the TPyPP and TPyPP(Ni) to DNA were 4.65 × 105 M−1 and 3.2 × 105 M−1, respectively. A colored precipitate was found after time in two porphyrin''s viscosity measurement. The reasonable interpretation is the porphyrins with alkyl connected N-position of pyridine can strongly interact with the anionic phosphates of DNA and lead to hydrophobic complex. [Copyright &y& Elsevier]