Manganese(II) complexes with 5–nitro–2–hydroxy–benzaldehyde or substituted 2–hydroxy–phenones: Structure and interaction with bovine serum albumin and calf–thymus DNA

A series of Mn(II) complexes of 5–nitro–salicyladehyde or substituted 2–hydroxy–phenones (HL) were synthesized in the absence or presence of a N,N′–donor co–ligand such as 2,2′–bipyridine, 1,10–phenanthroline, or 2,2′–bipyridylamine. The resultant coordination compounds were formulated as [Mn(L)2(CH3OH)2] (1–3) and [Mn(L)2(N,N′–donor)] (4–14), respectively, and characterized by diverse techniques. The crystal structures of three complexes were determined by single–crystal X–ray crystallography. Diverse techniques were employed to study the interaction of the complexes with calf–thymus DNA and showed intercalation as the most possible mode of their tight interaction. The affinity of the complexes for bovine serum albumin was investigated by fluorescence emission spectroscopy in order to calculate the binding constants which suggested a tight and reversible binding. A series of manganese(II) complexes with 5-nitro-salicyladehyde or substituted 2-hydroxy-phenones as ligands were isolated and characterized. In vitro biological studies revealed that the compounds can intercalate to calf-thymus DNA and bind tightly and reversibly to bovine serum albumin. [Display omitted] •Manganese(II) complexes with 5–nitro–2–hydroxy–benzaldehyde were characterized.•Manganese (II) coordination compounds with substituted 2–hydroxy–phenones were isolated.•Intercalation is the most possible interaction mode of complexes with calf-thymus DNA.•The complexes may bind tightly and reversibly to bovine serum albumin.