Removal of cefalosporin group antibiotics from waste water by DFT method

In this study, Cephalosporins, which are in the class of ß-Lactam antibiotics, are the second largest group after penicillin; The possible reaction pathways of the antibiotics cefacetril, ceftibuten, ceftaroline fosamil, cefkinom, cefsulodin, cefodizim and cefovesin with the hydroxyl radical were determined. Optimized geometries draw with Gaussian calculations were made in Gaussian09 View 5 software package. The most stable conformation of pharmaceutical compounds was determined by conformation analysis with molecular mechanical MM Method. Quantum mechanical calculations were made in the gas phase using the density functional theory DFT/B3LYP/6-31G* method and the optimum geometric parameters, thermodynamic and electronic properties of each molecule were calculated. Due to the electrophilic character of the OH radical, it will attack the electron-rich regions of the molecule, and the Mulliken charge distribution of the antibiotics was also calculated in order to determine the reaction centers. The impact of water solvent was investigated by using COSMO as the solvation model.These results will guide experimental studies and determine the fragmentation mechanism.