| abstract |
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 R.C.CO NH- PARALLEL N ¦a OR where R is a hydrogen atom or an organic group and Ra 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. |