title: PS-6 and PS-7, new beta-lactam antibiotics. Isolation, physicochemical properties and structures.
abstract: Antibiotics PS-6 and PS-7 which are shown to be 5R,6R-3-(2-acetamido)ethylthio-6-isopropyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene- 2-carboxylic acid and 5R,6R-3-(E)-(2-acetamido) vinylthio-6-ethyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid respectively, are new beta-lactam compounds isolated from fermentation broths of Streptomyces cremeus subsp. auratilis A271, S. fulvoviridis A933, S. olivaceus ATCC 31126 and S. flavogriseus NRRL 8139. Fermentation, isolation, physicochemical properties and structures of antibiotics PS-6 and PS-7 are described.
mesh_terms: D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000302:isolation & purification; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005285:Fermentation; D013302:Streptomyces / Q000378:metabolism; D013845:Thienamycins; D047090:beta-Lactams / Q000096:biosynthesis / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D013845:Thienamycins; D047090:beta-Lactams; C027836:antibiotic PS 7; C027835:antibiotic PS 6