title: Ro 22-5417, a new clavam antibiotic from Streptomyces clavuligerus. III. Absolute stereochemistry.
abstract: The complete stereostructure of the new antibiotic Ro 22-5417 has been established as 3-[(3S,5S)-7-oxo-1-aza-4-oxabicyclo[3.2.O]hept-3-yl]-L-alanine. This result together with the synthesis of an (3R,5R)-L-analog allowed us to postulate that clavams require the R-configuration at the ring juncture for beta-lactamase inhibitory activity, while the opposite S-stereochemistry is essential for antifungal activity.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D055598:Chemical Phenomena; D002621:Chemistry; D002969:Clavulanic Acids / Q000494:pharmacology; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism; D013302:Streptomyces / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D002969:Clavulanic Acids; C037743:3-(7-oxo-1-aza-4-oxabicyclo(3.2.0)hept-3-yl)alanine