ABSTRACT

The discovery of the nucleus of cephalosporin C followed by the production of 7-aminocephalosporanic acid and chemical modifications of the N-acyl side chain and of the substitutent at the C-3 position of the cephem nucleus enabled pharmaceutical manufacturers to produce many kinds of cephalosporins. This chapter describes the advance of cephem, oxacephem, and carbacephem derivatives. A. Ejima et al. prepared a new series of cephalosporins with a 2–(2-amino thiazol-4-yl)-2-methoxyiminoacetoamido and a 1-pyridinium group at the C-7 and C-3 positions. BO-1236 has especially potent activity against Pseudomonas aeruginosa, including ceftazidime-resistant strains. Cefepime, having improved antistaphylococcal activity while retaining the high antipseudomonal activity of ceftazidime, was discovered. B. A. Weissberger et al. reported the in vitro antibacterial spectrum of L-658,310 against a wide variety of randomly selected human clinical isolates in the United States. B. G. Christensen et al. synthesized a 1-carbacephem compound, initially together with 1-oxacephem.