Synthesis and in vitro antibacterial activities of 3-thiazol-4-yl-1-carba-1-dethiacephalosporins.

The synthesis and microbiological evaluation of a new series of 3-thiazol-4-yl-carba-1-dethiacephalosporins is described. Structure activity relationship was achieved by changing substitution at the 2-position of the thiazole moiety. The result was a marked variance of microbiological activity in the C7 side-chain derivatives. ATMO derivatives possess potent activity against both Gram-positive and Gram-negative bacteria. For example, MICs (microgram/ml) of LY215226 against representative organisms are as follows: S. aureus 0.25, S. pneumoniae 0.008, H. influenzae 0.008, E. coli 0.25, K. pneumoniae 0.008, E. cloacae 0.5, S. typhi 0.25, and M. morganii 0.25.