Boseimycin--a new streptothricin-like antibiotic.

During an antibiotic screening programme, a new biologically active complex was isolated from an unidentified Streptomyces, strain Ac6 5691}, which was obtained from a garden soil in Calcutta, India. This antibiotic complex was found to contain two water-soluble active fractions of which the major one was designated as boseimycin. This commuication describes the isolation, purification and characterization of boseimycin. It was found to have a close relationship to the streptothricin group of antibiotics but was differentiated from them on the basis of its physico-chemical and microbiological properties.