| abstract |
A compound represented by general formula (I), a process for producing the same, and the use thereof as an antibacterial wherein R1 either represents hydrogen or lower alkyl, or forms a heterocyclic ring together with R3; R2 represents hydrogen, ester residue, alkali metal or anionic charge; and R?3 and R4¿ represent each independently hydrogen or a hydrocarbon group which may bear a heteroatom selected from among oxygen, sulfur and nitrogen, or R?3 and R4¿ are combined together with the nitrogen atom to which they are bonded to form a heterocyclic group. |