title: Cepacin A and cepacin B, two new antibiotics produced by Pseudomonas cepacia.
abstract: Two new acetylenic antibiotics, cepacins A and B, have been isolated from the fermentation broth of Pseudomonas cepacia SC 11,783 and assigned structures 1 and 2. Cepacin A has good activity against staphylococci (MIC 0.2 micrograms/ml) but weak activity against streptococci (MIC 50 micrograms/ml) and the majority of Gram-negative organisms (MIC values 6.3 approximately greater than 50 micrograms/ml). Cepacin B has excellent activity against staphylococci (MIC less than 0.05 micrograms/ml) and some Gram-negative organisms (MIC values 0.1 approximately greater than 50 micrograms/ml).
mesh_terms: D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D005285:Fermentation; D007783:Lactones / Q000302:isolation & purification / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D011549:Pseudomonas / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000900:Anti-Bacterial Agents; D007783:Lactones; C041569:cepacin B; C041568:cepacin A