| 摘要 |
Compounds of the following formula I <IMAGE> (I) wherein X represents a sulphur or an oxygen atom, R is hydrogen or a C1-C4 alkyl group either unsubstituted or substituted by one or more substituents chosen from a free or protected hydroxy group and halogen atom; A is a Z, Z-O-CO- or -Z-CO- residue, wherein Z represents (a) an optionally substituted phenylene or naphthylene group, (b) an optionally substituted heterocyclediyl radical wherein the hetero ring is mono or bicyclic, saturated or unsaturated containing at least one heteroatom selected from the group of oxygen, sulphur and nitrogen; (c) an optionally substituted linear or branched C1-C7 alkylene radical; (d) a C2-C4 alkenylene or alkynylene group or a group of formula <IMAGE> (e) an optionally substituted C3-C8 cycloalkylene ring; (f) an aralkylene radical of the formula <IMAGE> wherein n is 1, 2 or 3; and Q(+) represents a +NR1R2R3 group, wherein (i) R1, R2, R3, are each independently an optionally substituted alkyl, aralkyl or aryl radical; or p1 (ii) R1 is as defined above under (i) and R2, R3 taken together with the nitrogen atom represent an optionally substituted heterocyclic or fused heterocyclic radical; or (iii) R1, R2, R3, taken together with the nitrogen atom, represent an optionally substituted azoniabicyclo or azoniatricyclo radical; or (iv) R1, R2, R3, taken together with nitrogen atom, represent an optionally substituted pyridinium, pirazinium, pyrazolium, or pyridazinium radical, such radicals being optionally fused with one phenyl ring or with a 5-7 membered, saturated or unsaturated cycloaliphatic or heterocyclic ring, or a pharmaceutically or veterinarily acceptable salt thereof having high antibacterial activity.
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