Mutilin derivatives having a heteroaromatic ring carboxylic acid structure 14 position substituent

To provide a novel mutilin derivative having a substitution at the 14-position, which is a novel mutilin analogue exhibiting a potent and broad antimicrobial action against Gram-positive bacteria and Gram-negative bacteria including various drug-resistant bacteria, and which is expected to be useful as an agent for treating infectious diseases. A mutilin derivative represented by the following general formula (1): or a pharmaceutically acceptable addition salt thereof.