| abstract |
A novel derivative of pyridonecarboxylic acid or a salt thereof having an excellent effect on bacteria such as methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Clostridium difficile is provided and is not susceptible to drug flow pumps and an antimicrobial agent that he understands it; a pyridonecarboxylic acid derivative represented by the formula (1), wherein R1 is a hydrogen atom, a halogen atom, a lower alkyl group or an amino group; R2 is a -NH-R6 group, wherein R6 is a hydrogen atom, a lower alkyl group, a lower alkylamino group, or the like; a group -O-R7, wherein R7 is a hydrogen atom, a lower alkyl group, or the like; a group - (CH2) m-R8, wherein R8 is an amino group or the like and m is an integer from 1 to 4); or a cyclic amino group represented by the following formula (2), wherein Y represents NH or C-R9aR9b, wherein R9a and R9b are each independently a hydrogen atom, a lower alkyl group, an amino group, an amino group lower alkyl, or the like; and n and p are an integer of 1 or 2; R3 is a hydrogen atom, a halogen atom, a lower alkyl group, or the like; R4 is a hydrogen atom or a carboxyl group protecting group; and R5 is a hydrogen atom or a hydroxyl group protecting group; or a salt thereof. (see formulas). |