title: Structure of the spiroketal-macrolide ossamycin.
abstract: Ossamycin is a cytotoxic agent of undetermined structure that was originally isolated in 1965 from culture broths of Streptomyces hygroscopicus var. ossamyceticus. Its overall structure and relative stereochemistry have now been determined by single crystal X-ray diffraction studies. Absolute stereochemistry was established according to the previously determined configuration of its aminosaccharide constituent, ossamine. The aglycone of ossamycin possesses a 24-membered macrolide ring system onto which is incorporated both a 6,6-spiroketal and 5-membered hemiketal ring system. The overall three-dimensional structure possesses features in common with the related macrocyclic antibiotics dunaimycin, cytovaricin, and A82548A.
authors.affiliation: Lilly Research Laboratories, Greenfield, Indiana 46140, USA.
authors.forename: H A
authors.initials: HA
authors.lastname: Kirst
authors.forename: J S
authors.initials: JS
authors.lastname: Mynderse
authors.forename: J W
authors.initials: JW
authors.lastname: Martin
authors.forename: P J
authors.initials: PJ
authors.lastname: Baker
authors.forename: J W
authors.initials: JW
authors.lastname: Paschal
authors.forename: J L
authors.initials: JL
authors.lastname: Rios Steiner
authors.forename: E
authors.initials: E
authors.lastname: Lobkovsky
authors.forename: J
authors.initials: J
authors.lastname: Clardy
mesh_terms: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents / Q000737:chemistry*; D018360:Crystallography, X-Ray; D018942:Macrolides / Q000737:chemistry; D015394:Molecular Structure; D013057:Spectrum Analysis; D013237:Stereoisomerism
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D018942:Macrolides; C008717:ossamycin