title: Two new monobactam antibiotics produced by a Flexibacter sp. I. Taxonomy, fermentation, isolation and biological properties.
abstract: Two new beta-lactam antibiotics, namely SQ 28,502 and SQ 28,503, have been isolated from fermentations of a Flexibacter sp. They are demethoxy monobactams with oligopeptide side chains and have molecular weights of 1,462 and 1,446, respectively. These beta-lactams show a high degree of stability to a variety of beta-lactamases and act as potent irreversible inactivators of P99 beta-lactamase from Enterobacter cloacae. They exhibit weak antibacterial activity.
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000633:toxicity; D001419:Bacteria / Q000187:drug effects; D041964:Cytophagaceae / Q000145:classification / Q000254:growth & development*; D005285:Fermentation; D007769:Lactams; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D008997:Monobactams; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D007769:Lactams; D008997:Monobactams; C039861:SQ 28502; C039862:SQ 28503