An objective of the present invention is to provide compounds of formula (1) or their pharmacologically acceptable salts or solvates wherein A represents aryl； R 1 represents N-optionally substituted C 1-6 alkyl-N-optionally substituted C 1-6 alkylamino-C 1-6 alkyl； R 2 represents a hydrogen atom or optionally substituted C 1-6 alkyl； R 3 represents optionally substituted C 1-6 alkyl or C 3-6 cycloalkyl-C 1-4 alkyl； m is 1 to 3； n is 0； and p is 0 to 2. The compounds are novel lincomycin derivatives that have a potent activity against resistant Streptococcus pneumoniae, which have recently posed problems, in the treatment of infectious diseases. Further, the compounds are usable as antimicrobial agents and are useful for preventing or treating bacterial infectious diseases.
