Abstract
As an extension of the investigations on structure-activity relationships of viomycin (VM), a tuberculostatic antibiotic, chemical modifications of its chromophore group by oxidative reactions were studied. Oxidations with KMnO4 gave normal oxidation products named oxoviomycin and its derivative while, with bromine, gave abnormal products V, VI and VIII, those of which were characterized by chemical and physical analyses. Antimicrobial potencies of both oxidation products of VM showed the nullified activities, the results of which were agreeable from the predictions that D-form or dehydro derivative of amino acid residue is important factor for their potencies of original antibiotics.
