Synthesis and structure-activity relationships of cephalosporins with C-3' catechol-containing residues

Cephalosporins with new catechol substituents at C-3' have been synthesized, including novel compounds with C-3' carbon-carbon bonds. Many of these compounds have high potency against Gram-negative bacteria, in particular against resistant strains like Pseudomonas aeruginosa. Structure-activity relationships are discussed in terms of their dependence on the pKa of the C-3' catechol and also in terms of steric and conformational factors of the C-3' substituent. The best overall properties were found in compounds with a bulky and/or conformationally restricted acidic C-3' catechol.