| abstract |
Compounds of the formula (II) <CHEM> or a salt, N-oxide or acyl derivative thereof, wherein Y is a group <CHEM> which is optionally substituted; X<1> is an oxygen or sulphur atom, a group CH2, a group S(O)n where n=1 or 2, a group NR<1> wherein R<1> is hydrogen, C1-4 alkyl or a group COR<2> wherein R<2> is hydrogen, C1-4 alkoxy or amino @@@<2> is a six-membered ring containing a nitrogen atom; @@@<3> is a six-membered ring optionally containing a nitrogen atom and the dotted lines represent single or double bonds, have antimicrobial activity. Processes for making these compounds, pharmaceutical compositions containing them and the medical use of the compounds are also disclosed. |