Influence of chirality using Mn(III) salen complexes on DNA binding and antioxidant activity

• Published in: Organic & biomolecular chemistry Vol. 8; no. 19; p. 4297
• Main Authors: Khan, Noor-Ul H, Pandya, Nirali, Kumar, Manoj, Bera, Prasanta Kumar, Kureshy, Rukhsana I, Abdi, Sayed H R, Bajaj, Hari C
• Format: Journal Article
• Language: English
• Published: England 07-10-2010
• Subjects: Animals; Antioxidants - chemical synthesis; Antioxidants - chemistry; Antioxidants - pharmacology; Biphenyl Compounds - metabolism; Cattle; Circular Dichroism; DNA - metabolism; Free Radicals - metabolism; Hydrogen Peroxide - metabolism; Ligands; Manganese Compounds - chemical synthesis; Manganese Compounds - chemistry; Manganese Compounds - pharmacology; Nucleic Acid Denaturation - drug effects; Picrates - metabolism; Stereoisomerism; Superoxides - metabolism; Viscosity - drug effects
• ISSN: 1477-0539
• DOI: 10.1039/c0ob00010h

Chiral Mn(iii) salen complexes S-1, R-1, S-2, R-2, S-3 and R-3 derived from the respective chiral salen ligands, viz., (1S,2S)-N,N'-bis-[3-tert-butyl-5-chloromethyl-salicylidine]-1,2-cyclohexanediamine S-1'/(1R,2R)-N,N'-bis-[3-tert-butyl-5-chloromethyl-salicylidine]-1,2-cyclohexanediamine R-1'/(1S,2S)-N,N'-bis-[3-tert-butyl-5-N,N'N'triethylaminomethyl-salicylidine]-1,2-cyclohexanediamine dichloride S-2'/(1R,2R)-N,N'-bis-[3-tert-butyl-5-N,N'N'triethylaminomethyl-salicylidine]-1,2-cyclohexanediamine dichloride R-2'/(1S,2S)-N,N'-bis-[3,5-di-tert-butylsalicylidene]-1,2-cyclohexanediamine S-3' and (1R,2R)-N,N'-bis-[3,5-di-tert-butyl-salicylidene]-1,2-cyclohexanediamine R-3', were synthesized. Characterization of the complexes was done by microanalysis, IR, LC-MS, UV-vis. and circular dichroism (CD) spectroscopy. Binding of these complexes with calf thymus DNA (CT-DNA) was studied by absorption spectroscopy, competitive binding study, viscosity measurements, circular dichroism measurements, thermal denaturation study and observation of their different antioxidant activities. Among all the complexes used, the best result in terms of binding constant (intercalative) (130.4 x 10(4)) was achieved with the complex S-1 by spectroscopic titration. The complex S-1 showed strong antioxidant activity as well.