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The DNA binding of amphiphilic iron(III) 2,17-bis(sulfonato)-5,10,15-tris(pentafluorophenyl)corrole complex (Fe-SC) was studied using spectroscopic methods and viscosity measurements. Its nuclease-like activity was examined by using pBR322 DNA as a target. The interaction of Fe-SC with human serum albumin (HSA) in vitro was also examined using multispectroscopic techniques. Experimental results revealed that Fe-SC binds to ct-DNA via an outside binding mode with a binding constant of 1.25 × 104 M-1. This iron corrole also displays good activity during oxidative DNA cleavage by hydrogen peroxide or tert-butyl hydroperoxide oxidants, and high-valent (oxo)iron(V,VI) corrole intermediates may play an important role in DNA cleavage. Fe-SC exhibits much stronger binding affinity to site II than site I of HSA, indicating a selective binding tendency to HSA site II. The HSA conformational change induced by Fe-SC was confirmed by UV/Vis and CD spectroscopy. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Cationic meso(4- N-methylpyridyl)-based metallocorroles, μ-oxo iron corrole dimer ( 1b) and manganese corrole monomer ( 2b), were synthesized and characterized. The interactions of these two metal corrole complexes with CT-DNA were studied by UV-visible, fluorescence and circular dichroism spectroscopic methods, as well as by viscosity measurements. The results revealed that 1b interacts with CT-DNA in a difunctional binding mode, i.e. non-classical intercalation and outside groove binding with H-aggregation, while 2b can interact with CT-DNA via an outside groove binding mode only. The binding constants Kb of 1b and 2b were 4.71 × 105 m−1 and 2.17 × 105 m−1, respectively, indicating that 1b can bind more tightly to CT-DNA than 2b. Furthermore, both complexes may cleave the supercoiled plasmid DNA efficiently in the presence of or tert-butyl hydroperoxide (TBHP), albeit 1b exhibited a little higher efficiency. The inhibitor tests suggested that singlet oxygen and high-valent (oxo)iron(VI) corrole or (oxo)manganese(V) corrole might be the active intermediates responsible for the oxidative DNA scission. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]