The invention relates to novel 7.alpha.-methoxycephalosporin derivatives having at the 7.beta.-position an amido group acylated by a 1,3-dithietane carboxylic acid residue and to 7.beta.-isothiazolylthioacetamido-7.alpha.-methoxycephalosporins having antibacterial activity by themselves and, as the case may be, capable of being converted into the aforesaid 7.alpha.-methoxycaphalosporin derivatives. The compounds of this invention exhibit excellent antibacterial activity and are particularly effective against gram negative bacteria.
                            本发明涉及一种新型7α-甲氧基
头孢菌素衍
生物,其在7β-位置具有一个被1,3-二
硫杂
环戊烷羧酸残基酰化的酰胺基,以及具有抗菌活性的7β-
异噻唑硫乙酰胺基-7α-甲氧基
头孢菌素,如有必要,可转化为上述7α-甲氧基
头孢菌素衍
生物。本发明的化合物表现出优异的抗菌活性,特别是对革兰氏阴性菌非常有效。