The crystal structure of sulfamethoxazole, interaction with DNA, DFT calculation, and molecular docking studies

作者：Das D; Sahu N; Roy S; Dutta P; Mondal S; Torres E L; Sinha C

来源：Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy , 2014, 137: 560-568.

DOI：10.1016/j.saa.2014.08.034

• DFT and TD-DFT computation
• DNA interaction
• Docking studies
• Sulfamethoxazole
• X-ray structure

Sulfamethoxazole (SMX) [4-amino-N-(5-methyl-1,2-oxazol-3-yl)benzenesulfonamide] is structurally established by single crystal X-ray diffraction measurement. The crystal packing shows H-bonded 2D polymer through N(7)H(7A) - -O(2), N(7)H(7B) - -O(3), N(1)H(1) - -N(2), C(5)H(5) - -O(3)S(1) and N(7)(H7A) - -O(2)S(1). Density Functional Theory (DFT) and Time Dependent-DFT (TD-DFT) computations of optimized structure of SMX determine the electronic structure and has explained the electronic spectral transitions. The interaction of SMX with CT-DNA has been studied by absorption spectroscopy and the binding constant (Kb) is 4.37 × 104M-1. The in silico test of SMX with DHPS from Escherichia coli and Streptococcus pneumoniae helps to understand drug metabolism and accounts the drug-molecule interactions. The molecular docking of SMX-DNA also helps to predict the interaction feature.