Spectroscopic characterization, biological activities and theoretical computation of manganese(II) and copper(II) complexes of sulfamethoxazolyl-azo-acetylacetonate
Description
Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata-700 032, India
E-mail : c_r_sinha@yahoo.com
Department of Biotechnology, Haldia Institute of Technology, Haldia, Purba Medinipur-721 657,
West Bengal, India
Manuscript received 20 January 2017, accepted 07 February 2017
[4-(Z)-((2-Hydroxy-4-oxopent-2-en-3-yl)diazenyl)-N-(5-methylisoxazol-3-yl)benzene sulfonamide] (sulfamethoxazolyl-azo-acetylacetone, HL) serves as monoanionic N,O chelator and has been used to synthesize manganese(II), [Mn(L)2 (H2O)4 ] (1) and copper(II), [Cu(L)2 (H2O)4 ] (2) complexes. Different physicochemical techniques (FT-IR, UV-Vis, Mass, SEM-EDX, thermal, bulk magnetic moment, EPR) have been employed to establish the structure and electronic configuration of the complexes. The interaction of CT-DNA with [Mn(L)2 (H2O)4 ] (KbMn, 1.26×106 M–1) is stronger than [Cu(L)2 (H2O)4 ] (KbCu, 6.12×105 M–1) while HL shows least interaction (KbHL, 6.09×105 M–1). Antimicrobial activity of them have also been examined against B. subtillis (ATCC 6633; IC50 77.25 µg/ml (HL), 84.01 µg/ ml (1) and 81.5 µg/ml (2)) and E. coli (ATCC 8739; IC50 63.72 µg/ml (HL), 84.01 µg/ml (1) and 85.19 µg/ml (2)). In silico test is used to predict the most favored binding pose of the complexes with the active site residues of DHPS (dihydropteroate synthetase) protein of E. coli. [Cu(L)2 (H2O)4 ] (2) binds more efficiently [∆G# , –2.59 kcal/mol] than [Mn(L)2 (H2O)4 ] (1) [∆G# , –1.44 kcal/mol]. DNA docking (1BNA) also shows the binding with the complex 2 (∆G† , –2.87 kcal/mol) is stronger than that of complex, 1 [∆G† , –2.65 kcal/mol].