title: Three novel hydroxybenzoate saxitoxin analogues isolated from the dinoflagellate Gymnodinium catenatum.
abstract: In a recent survey of paralytic shellfish poisoning (PSP) toxins in Gymnodinium catenatum Graham extracts, using LC with postcolumn oxidation and fluorescence detection, three novel saxitoxin analogues were revealed in isolates from several locations, including Australian waters. We have named them as G. catenatum toxins, GC1 (1), GC2 (2), and GC3 (3). The compounds were isolated from a culture of the Australian strain by LC-MS-guided fractionation employing a C18-silica column and hydrophilic interaction chromatography. The unusual structures of these novel compounds were characterized by low- and high-resolution MS, MS/MS, and NMR spectroscopy. GC3 (3) was found to be the 4-hydroxybenzoate ester derivative of decarbamoylsaxitoxin, while GC1 (1) and GC2 (2) are the epimeric 11-hydroxysulfate derivatives of GC3 (3).
authors.affiliation: Australian Institute of Marine Science, PMB 3, Townsville MC, 4810, Australia. a.negri@aims.gov.au
authors.forename: Andrew
authors.initials: A
authors.lastname: Negri
authors.forename: David
authors.initials: D
authors.lastname: Stirling
authors.forename: Michael
authors.initials: M
authors.lastname: Quilliam
authors.forename: Susan
authors.initials: S
authors.lastname: Blackburn
authors.forename: Chris
authors.initials: C
authors.lastname: Bolch
authors.forename: Ian
authors.initials: I
authors.lastname: Burton
authors.forename: Geoff
authors.initials: G
authors.lastname: Eaglesham
authors.forename: Krista
authors.initials: K
authors.lastname: Thomas
authors.forename: John
authors.initials: J
authors.lastname: Walter
authors.forename: Rick
authors.initials: R
authors.lastname: Willis
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D004141:Dinoflagellida / Q000737:chemistry*; D062385:Hydroxybenzoates / Q000302:isolation & purification / Q000633:toxicity*; D009682:Magnetic Resonance Spectroscopy; D008387:Marine Toxins / Q000302:isolation & purification / Q000633:toxicity*; D013058:Mass Spectrometry; D015394:Molecular Structure; D012530:Saxitoxin / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000633:toxicity*
chemical_list: D062385:Hydroxybenzoates; D008387:Marine Toxins; D012530:Saxitoxin