Pyridonecarboxylic acid derivatives or salts thereof and antibacterial agents containing the same as the active ingredient

摘要

A novel pyridonecarboxylic acid derivative or its salt exhibiting satisfactory antibacterial activities, intestinal absorption, metabolic stability, and reduced side effects, in particular, phototoxicity and cytotoxicity, as well as an antibacterial agent containing such pyridonecarboxylic acid derivative or its salt are provided.For such an object, a pyridonecarboxylic acid derivative represented by the following formula (1):(wherein R1 represents hydrogen atom, a halogen atom or a lower alkyl group; R2 represents hydrogen atom or a lower alkyl group; R3 represents substituted or unsubstituted amino group or hydroxyl group; and R4 represents hydrogen atom, a lower alkyl group, amino group or nitro group) or its salt is provided.