The invention relates to antibacterial compounds of formula Iwherein R1 is one of the groups represented belowwherein A is a bond, CH=CH or C≡C; U is N or CH; V is N or CH; W represents N or CH; and R1A, R2A, R3A, R1B and R1C are as defined in the claims; and salts thereof.本發明係關於抗菌之式I化合物及其鹽,其中R1係下文所代表基團中之一者:其中A係鍵、CH=CH或C≡C;U係N或CH;V係N或CH;W代表N或CH;且R1A、R2A、R3A、R1B及R1C係如申請專利範圍中所定義。