Butirosin, a new water-soluble aminoglycosidic antibiotic complex, active against gram-positive and gram-negative bacteria, has been isolated from fermentation filtrates of Bacillus circulans by ion exchange. The complex has been resolved into isomeric A and B components, C21H41N5012, by means of Dowex 1 X 1 or Dowex 1 X 2 chromatography. Properties ofthe free bases and the N, N', N", N"'-tetraacetyl derivatives of butirosin A and B are given.
The isolation of two new antibiotics, PD 114,759 and PD 115,028, exhibiting in vivo antitumor activity at extremely low doses is described. The physico-chemical properties of these sulfur-containing compounds show that they represent a novel class of antitumor agents.
The isolation and characterization of the title antibiotics, which are produced by the same Streptomyces sp., is described. The potent antitumor agent, PD 124,895, is an analog of hydroxyelactocin (PD 114,721). PD 124,966 is a new member of the depsipeptide family of antibiotics.Recently we reported the isolation of the novel antitumor agents elactocin (1)1 and hydroxyelactocin (2)1.2). During the fractionation of fermentation beers containing these antibiotics, the
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.