title: Isolation and structure elucidation of new and unusual saxitoxin analogues from mussels.
abstract: Chemical analyses of plankton and highly toxic mussel samples collected in eastern Canada during an intense bloom of the dinoflagellate Alexandrium tamarense established the presence of a complex mixture of paralytic shellfish poisoning (PSP) toxins. Application of a newly developed technique, hydrophilic interaction liquid chromatography-mass spectrometry, confirmed the identities of the known toxins and revealed the presence in the mussels of five saxitoxin analogues (M1-M5) that were not present in the plankton. Four of these compounds were isolated and their structures established by tandem mass spectrometry, 1D- and 2D-NMR spectroscopy, and chemical interconversion experiments. One of these was found to be 11beta-hydroxysaxitoxin (M2), while the other three were found to be new saxitoxin analogues, namely, 11beta-hydroxy-N-sulfocarbamoylsaxitoxin (M1), 11,11-dihydroxy-N-sulfocarbamoylsaxitoxin (M3), and 11,11-dihydroxysaxitoxin (M4). Compound M5 remains unidentified because of insufficient material for characterization.
authors.affiliation: Institute for Marine Biosciences, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada.
authors.forename: Carmela
authors.initials: C
authors.lastname: Dell'Aversano
authors.forename: John A
authors.initials: JA
authors.lastname: Walter
authors.forename: Ian W
authors.initials: IW
authors.lastname: Burton
authors.forename: David J
authors.initials: DJ
authors.lastname: Stirling
authors.forename: Ernesto
authors.initials: E
authors.lastname: Fattorusso
authors.forename: Michael A
authors.initials: MA
authors.lastname: Quilliam
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D002170:Canada; D004141:Dinoflagellida / Q000737:chemistry*; D008387:Marine Toxins / Q000737:chemistry* / Q000302:isolation & purification*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D012530:Saxitoxin / Q000031:analogs & derivatives / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: D008387:Marine Toxins; D012530:Saxitoxin