MECHANISTIC STUDIES AND BIOLOGICAL-ACTIVITY OF BIOXALOMYCIN ALPHA(2),A NOVEL ANTIBIOTIC PRODUCED BY STREPTOMYCES-VIRIDODIASTATICUS SUBSP LITORALIS LL-31F508

The bioxalomycins, a novel complex of broad-spectrum antibiotics, were isolated from fermentations of Streptomyces viridodiastaticus subsp. ''litoralis'' LL-31F508. Bioxalomycin alpha(2), the major. component o f this complex, exhibited antibacterial activity. The MICs ranged from less than or equal to 0.002 to 0.008 mu g/ml for gram-positive organi sms and from 0.50 to 4 mu g/ml for gram-negative organisms. Bioxalomyc in a, was found to be bactericidal and to inhibit bacterial DNA synthe sis preferentially. Bioxalomycin or, protected mice from a lethal chal lenge with Staphylococcus aureus Smith. The 50% effective dose of biox alomycin alpha(2) administered orally was 10 times greater than that w hen the drug was given subcutaneously or intravenously. These data sug gest a stability or bioavailability problem when the compound is admin istered orally.