Mössbauer spectroscopy, anti-tubercular activity, docking, and HSA binding studies of Fe (III) complexes of selenosemicarbazones

Abstract

Reaction of cyclohexanone selenosemicarbazone (Hcysesc), 2-furfural selenosemicarbazone (2-Hfursesc), 1-methyl isatinselenosemicarbazone (1-Hmeistsesc), 3-indole selenosemicarbazone (3-Hinsesc), and 3-acetyl indole selenosemicarbazones with iron(III) acetate in 3: 1 (L: M) yielded complexes of stoichiometry, [Fe(L)3] (L = anionic form of cysesc 1; 2-fursesc 2; 5-ClHinsesc) 5, 1-meistsesc 6; 3-insesc 7; 3-acinsesc 8), whereas with 2-thiophene selenosemicarbazoe (2-Hthiosesc) and N-methyl-2-pyrrole selenosemicarbazone (N-Hmepysesc) formed complexes, [Fe(2-thiosesc)2](CH3COO) 3 and [Fe(N-mepysesc)2](CH3COO) 4, respectively. Complexes were characterized using elemental analysis, IR, and mass and M & ouml;ssbauer spectroscopy. Isomer shift and quadrupole splitting of major species in 1, 2, 5-8 indicates high-spin Fe(III) in octahedral environment, whereas data supports coordination number four in 3 and 4. VSM analysis of complexes indicates that iron in these complexes is magnetically soft. All the complexes were tested for their anti-tubercular and antioxidant activities. The better ferric reducing antioxidant power of 3 (11.96 mu g TE/mL) and 5 (16.56 mu g TE/mL) can be correlated with the geometry or their coordination numbers. Results of anti-microbial activity showed a significant enhancement in the activity of 2, 4, 5, and 7 as compared to free ligands that are well supported by HSA binding studies and molecular modeling.