The invention provides novel antibiotic compounds which are 7.beta.-acylamidoceph-3-em-4-carboxylic acids, and non-toxic derivatives thereof characterized in that the acylamido group has the structure ##EQU1## where R is a hydrogen atom or an organic group and R.sup.a is an etherifying monovalent organic group linked to the oxygen atom through a carbon atom. The compounds are syn isomers or exist as mixtures containing at least 75% of the syn isomer. These antibiotic compounds possess high antibacterial activity against a range or gram positive and gram negative organisms coupled with particularly high stability to .beta.-lactamases produced by various gram negative organisms. The invention is also concerned with the administration of the compounds.
该发明提供了一种新型抗生素化合物,即7-β-酰胺基头孢-3-
乙烯-4-
羧酸及其非毒性衍
生物,其特征在于酰胺基具有以下结构:##EQU1## 其中R是氢原子或有机基团,R.sup.a是通过碳原子与氧原子连接的醚化一价有机基团。这些化合物是同构体或存在至少75%的同构体混合物。这些抗生素化合物具有高抗菌活性,可对一系列革兰氏阳性和革兰氏阴性微
生物产生高度的稳定性,其尤其对各种革兰氏阴性微
生物产生的β-内酰胺酶具有高度的稳定性。该发明还涉及该化合物的给药。