title: Spirolides isolated from Danish strains of the toxigenic dinoflagellate Alexandrium ostenfeldii.
abstract: Using LC/MS methodology, spirolides were detected in two clonal isolates of Alexandrium ostenfeldii isolated from Limfjorden, Denmark. Examination of the LC/MS profiles of extracts from these Danish cultures revealed the presence of two dominant peaks representing two previously unidentified spirolide components and one minor peak identified as the previously reported desmethyl spirolide C (1). Culturing of these clonal strains, LF 37 and LF 38, of A. ostenfeldii resulted in the accumulation of sufficient cell biomass to allow for the isolation and structure elucidation of two new spirolides, 13,19-didesmethylspirolide C (2) and spirolide G (3). While 2 was found to differ from 1 only in that it contained one less methyl group, 3 was the first spirolide to be isolated that contained a 5:6:6-trispiroketal ring system. The effect of this new feature on the toxicity of 3 relative to other spirolides is presently being pursued.
authors.affiliation: Institute for Marine Biosciences, National Research Council of Canada, 1411 Oxford Street, Halifax, Nova Scotia, Canada B3H 3Z1. shawna.mackinnon@nrc-cnrc.gc.ca
authors.forename: Shawna L
authors.initials: SL
authors.lastname: MacKinnon
authors.forename: John A
authors.initials: JA
authors.lastname: Walter
authors.forename: Michael A
authors.initials: MA
authors.lastname: Quilliam
authors.forename: Allan D
authors.initials: AD
authors.lastname: Cembella
authors.forename: Patricia
authors.initials: P
authors.lastname: Leblanc
authors.forename: Ian W
authors.initials: IW
authors.lastname: Burton
authors.forename: William R
authors.initials: WR
authors.lastname: Hardstaff
authors.forename: Nancy I
authors.initials: NI
authors.lastname: Lewis
mesh_terms: D000818:Animals; D003718:Denmark; D004141:Dinoflagellida / Q000737:chemistry*; D007097:Imines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008387:Marine Toxins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D015394:Molecular Structure; D013141:Spiro Compounds / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D007097:Imines; D008387:Marine Toxins; D013141:Spiro Compounds