Abstract The invention provides novel antibiotic compounds which are 7β-acylamidoceph-3-em-4-carboxylic acids, and non-toxic derivatives thereof characterized in that the acylamido group has the structure ##STR1## where R is a hydrogen atom or an organic group and R 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 of gram positive and gram negative organisms coupled with particularly high stability to β-lactamases produced by various gram negative organisms. The invention is also concerned with the administration of the compounds.
A compound selected from the group consisting of a cephalosporin antibiotic of the formula: ##STR151## wherein R is phenyl, naphthyl, thienyl, furyl, benzothienyl or benzofuryl and a physiologically acceptable salt thereof.
Claim 2
Dependent Claim
31 words
A compound selected from the group consisting of a cephalosporin antibiotic of the formula: ##STR151## wherein R is phenyl, naphthyl, thienyl, furyl, benzothienyl or benzofuryl and a physiologically acceptable salt thereof.
Claim 3
Dependent Claim
9 words
The compound of claim 1 which is 3-acetoxymethyl-7β-(2-carboxymethoxyimino-2-phenylacetamido)ceph-3-em-4-carboxylic acid.