The present invention addresses the problem of providing a novel compound which is useful as a pharmaceutical product, and which has high antibacterial activity with regard to gram-negative bacteria such as pseudomonas aeruginosa and with regard to the drug-resistant bacteria of gram-negative bacteria. The present invention provides an N-hydroxy-2-{[4-(7-hydroxy-hepta-1,3-diyne-1-yl)benzoyl](methyl)amino}-N,2-dimethyl propane diamide represented by formula [1], or a pharmaceutically-acceptable salt.本發明之課題在於提供一種對以綠膿桿菌為代表之革蘭氏陰性細菌及其耐藥性菌具有較強之抗菌活性而作為醫藥品有用之新穎化合物。本發明提供一種式[1]所表示之N-羥基-2-{[4-(7-羥基庚-1,3-二炔-1-基)苯甲醯基](甲基)胺基}-N,2-二甲基丙二醯胺或其藥學上所容許之鹽。
