title: 7-(D,L-alpha-fluoro-2-thienylacetamido)cephalosporanic acid (L 14655), a new semisynthetic cephalosporin. Synthesis and preliminary biological evaluation.
abstract: We describe the synthesis and some preliminary antimicrobial and enzymatic properties of 7-(D,L-alpha-fluoro-2-thienylacetamido)cephalosporanic acid (L 14655), a fluorinated derivative of cephalothin. L 14655 had antimicrobial activity similar to that of cephalothin. Cell-free studies demonstrated that L 14655 was very stable to hydrolysis by type Ia beta-lactamase (325 times more than cephalothin) but not to TEM enzyme. In addition, L 14655 was 480 times more active than cephalothin in preventing the hydrolysis of nitrocephin by type Ia enzyme. Preliminary studies in intact beta-lactamase-producing cells did not however produce evidence of enhanced activity of L 14655 relative to cephalothin.
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000494:pharmacology*; D001419:Bacteria / Q000201:enzymology; D002512:Cephalothin / Q000031:analogs & derivatives* / Q000032:analysis / Q000138:chemical synthesis / Q000494:pharmacology; D055598:Chemical Phenomena; D002621:Chemistry; D006868:Hydrolysis; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D065093:beta-Lactamase Inhibitors
chemical_list: D000900:Anti-Bacterial Agents; D065093:beta-Lactamase Inhibitors; C044782:7(alpha-fluoro-2-thienylacetamido)cephalosporanic acid; D002512:Cephalothin