- 374- ABSTRACT C\1jllGlNAL 92 81 ~uw12 "NOVEL HYDROXAMIC ACID DERIVATIVE" 26 OCT 2012 Provided is a novel compound which is useful as a pharmaceutical composition by inhibiting an LpxC activity, thereby exhibiting potent antimicrobial activity against gramnegative bacteria including Pseudomonas aeruginosa and its drug resistant bacteria. Provided is a hydroxamic acid derivative represented by the following general formula [1] or a pharmaceutically acceptable salt thereof: [Chemical formula 1]