| 摘要 |
Cephalosporin antibiotics of general formula (I) (wherein Ra and Rb, which may be the same or different, each represent a C1-4 alkyl group or Ra and Rb together with the carbon atom to which they are attached form a C3-7 cycloalkylidene group) exhibit broad spectrum antibiotic activity, particularly high activity against members of the Enterobacteriaceae, The invention also includes the non-toxic salts and non-toxic metabolically labile esters of compounds of formula (I), Also described are compositions containing the antibiotics of the invention and processes for the preparation of the antibiotics, |
