title: Structure of the new spiroketal-macrolide A82548A.
abstract: A new member of the spiroketal-containing macrolide class of fermentation-derived natural products was isolated from mycelial extracts of Streptomyces diastatochromogenes. The principal component, A82548A, was shown to possess a 22-membered macrolide ring system onto which was incorporated both a spiroketal and a hemiketal moiety. Relative stereochemistry was established by single crystal X-ray diffraction studies. Absolute stereochemistry was determined via hydrolysis of the amino sugar glycosidically linked to the aglycone, which was identified as L-kedarosamine. The overall three-dimensional structure is closely related to that of the macrolides cytovaricin, rutamycin, and ossamycin.
authors.affiliation: Lilly Research Laboratories, Greenfield, Indiana 46140, USA.
authors.forename: H A
authors.initials: HA
authors.lastname: Kirst
authors.forename: S H
authors.initials: SH
authors.lastname: Larsen
authors.forename: J W
authors.initials: JW
authors.lastname: Paschal
authors.forename: J L
authors.initials: JL
authors.lastname: Occolowitz
authors.forename: L C
authors.initials: LC
authors.lastname: Creemer
authors.forename: J L
authors.initials: JL
authors.lastname: 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 / Q000737:chemistry* / Q000302:isolation & purification*; D018360:Crystallography, X-Ray; D005285:Fermentation; D018942:Macrolides / Q000737:chemistry / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D013141:Spiro Compounds / Q000737:chemistry / Q000302:isolation & purification; D013237:Stereoisomerism; D013302:Streptomyces
chemical_list: C096633:A 82548A; D000900:Anti-Bacterial Agents; D018942:Macrolides; D013141:Spiro Compounds; C033385:cytovaricin