A water-soluble cationic gallium corrole, 5,10,15-tris(N-methyl-4-pyridyl)corrolatogallium(III) (3), was prepared and characterized. The photocytotoxicity of 3 was investigated using Hep G2 cancer cell line. Upon treatment with corrole 3 and irradiation, fragmentation of tumor cell nuclei was observed, which led to apoptosis. Flow cytometric analysis clearly showed the efficient induction of apoptotic cell death, and corrole 3 exhibited high photocytotoxicity towards Hep G2 cancer cells (IC₅₀ = 60 nM). Furthermore, the binding behavior of corrole 3 with c-MYC G-quadruplex DNA, a potent target for antitumor drugs, was investigated using spectroscopic methods and molecular docking simulation. Copyright © 2015 John Wiley & Sons, Ltd.

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.

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 K_b 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 hydrogen peroxide 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.

The interaction of calf thymus DNA (CT DNA) and water-soluble manganese corrole, 5,10,15-tris(4-carboxyphenyl)corrolatomanganese(III) (Mn^IIITCPC) has been studied by absorption spectra, fluorescence spectra and CD spectra, as well as by viscosity measurements. Results revealed that this manganese corrole binds to CT DNA via an outside groove binding mode with intrinsic binding constant K_b of 4.67×10⁴ L·mol−¹. DNA cleavage activities of Mn^IIITCPC in the presence of various oxidants were also investigated. Mn^IIITCPC can cleave the supercoiled plasmid pBR322 DNA to both nicked and linear form in the presence of hydrogen peroxide or tert-BuOOH, while no nuclease activity was observed by using KHSO₅ as oxidant. Inhibitor tests revealed that hydroxyl radicals or singlet oxygen was not involved in Mn^IIITCPC mediated DNA oxidative cleavage. It is suggested that (oxo)manganese(V) corrole is the possibly active intermediate in this oxidative cleavage reactions.