| abstract |
Abstract of the Disclosure: Cephalosporin derivatives which have an excellent antibacterial action particularly against bacteria belonging to genus Pseudomonas or Serratia and are represented by the formula: wherein R1, R2, R3, R4, R5, and n are as defined in the specifi-cation, and salts thereof; a process for preparing the same; and an antibacterial preparation containing the same as an active ingredient are disclosed. |