Olivanic acids, a family of beta-lactam antibiotics with beta-lactamase inhibitory properties produced by Streptomyces species. II. Isolation and characterisation of the olivanic acids MM 4550, MM 13902 and MM 17880 from Streptomyces olivaceus.

The olivanic acids MM 4550, MM 13902 and MM 17880 are members of a new family of beta-lactam antibiotics. An isolation and purification process utilising ion-par extraction and ion-exchange chromatography is described and the metabolites are characterised by physico-chemical and biological properties.

Production of chlorflavonin, an antifungal metabolite of Aspergillus candidus.

Production of chlorflavonin, a new antifungal antibiotic, by strains of Aspergillus candidus is described. Two wild strains of the fungus had distinctly different chlorflavonin-producing capabilities. One strain produced 25 mug of chlorflavonin per ml per 4 to 5 days in a pilot scale fermentor with stirring, using a medium containing corn steep liquor and glucose. Production of antibiotic was favored by high rates of agitation-aeration. Crude chlorflavonin was extracted from the whole brew with a hydrocarbon solvent and then purified by recrystallization from benzene and petroleum ether. The overall yield from fermentation brew to pure product was 50%.