CHALCOMYCIN, A NEW ANTIBIOTIC: BIOLOGICAL STUDIES

Abstract

Chalcomycin, a new, slightly water-soluble, organic-solvent-soluble, neutral antibiotic containing only carbon, hydrogen, and oxygen was obtained from filtrates of two new strains of Streptomyces bikiniensis. A paper-disk agar-diffusion assay, which employs Sarcina lutea PCI 1001 W as the test organism, has been developed. The sensitivity range of the assay is 1–10 μg chalcomycin/ml. Shaken flask fermentations in a medium containing glucose, yeast hydrolyzate, and meat peptone have produced titers of 200 μg/ml. Chalcomycin is primarily active against Staphylococcus aureus, including isolates resistant to various antibiotics, and Streptococcus pyogenes. In experimental mouse infections with various mouse-virulent strains of S. aureus, a single dose of chalcomycin gave oral ED50 values of 13 to 53 mg/kg and subcutaneous values of 8 to 47 mg/kg. Against S. pyogenes, oral and subcutaneous administration of a single dose gave ED50 values of 88 and 55 mg/kg, respectively. Chalcomycin was well tolerated by mice, rats, dogs, and monkeys.