Preparation, antibacterial evaluation and preliminary structure-activity relationship (SAR) study of benzothiazol- and benzoxazol-2-amine derivatives

In this study, a novel benzothiazol- and benzooxazol-2-amine scaffold with antibacterial activity was designed and synthesized. Preliminary structure-activity relationship analysis displayed that compound 8t with a 5,6-difluorosubstituted benzothiazole was found to be a potent inhibitor of Gram-positive pathogens, and exhibited some potential against drug-resistant bacteria and without cytotoxicity in therapeutic concentrations. In addition, molecular docking studies indicated that Staphylococcus aureus methionyl-tRNA synthetase might be the possible target of these compounds. Taken together, the present study provides an effective entry to the synthesis of a good lead for subsequent optimization and a new small molecule candidate drug for antibacterial therapeutics. (C) 2012 Elsevier Ltd. All rights reserved.