[Antibiotics formed by Actinomadura fulvescens].

Novel antibiotics with in vitro activity against gram-positive bacteria were isolated from Actinomadura fulvescens INA 3321 and INA 3852. Conditions for biosynthesis and isolation of antibiotics 3321 and 3852, as well as their physicochemical and biological properties were studied. Chromatographic analysis of the antibiotics revealed that each of them contained two biologically active components. The components were separated with preparative chromatography. Physicochemical properties of the components showed that antibiotics 3321 and 3852 were similar. UV and IR spectroscopy suggested that antibiotics 3321 and 3852 were original compounds not described earlier.