A compound represented by formula (I):
wherein R¹ represents a hydrogen atom or a methyl group; R² and R³, which may be the same or different, each represents a hydrogen atom or a lower alkyl group; and R⁴ represents a carboxyl group, a lower alkoxycarbonyl group, a carbamoyl group, a lower alkylcarbamoyl group, a di-lower alkylcarbamoyl group, or a carbonyl group substituted with a heterocyclic group selected from the group consisting of an aziridinyl group, an azetidinyl group, a pyrrolidinyl group, a piperidino group, a morpholino group, a thio-morpholino group, a piperazinyl group, and a 4-lower alkyl-1-piperazinyl group,
or a pharmaceutically acceptable salt or ester thereof. The compound of formula (I) and their salts or esters exhibit excellent antibacterial activity.
由式(I)代表的化合物:
其中 R¹ 代表氢原子或甲基;R² 和 R³(可以相同或不同)各自代表氢原子或低级烷基;和 R⁴ 代表羧基、低级烷氧羰基、
氨基甲酰基、低级烷基
氨基甲酰基、二低级烷基
氨基甲酰基或被杂环基团取代的羰基,该杂环基团选自由
氮丙啶基、氮杂
环丁烷基、氮杂
环丁烷基和氮杂
环丁烷基组成的组、氮杂
环丁基、
吡咯烷基、
哌啶基、吗啉基、
硫代吗啉基、
哌嗪基和 4-低级烷基-1-
哌嗪基、
或其药学上可接受的盐或酯。式(I)化合物及其盐或酯具有极佳的抗菌活性。