title: Quantitative analysis of azaspiracids in Azadinium spinosum cultures.
abstract: Azaspiracids (AZAs) are secondary metabolites of Azadinium spinosum that can accumulate in shellfish and cause food poisoning when consumed. We describe here an analytical procedure for the determination of AZAs in cultures of A. spinosum with a focus on the formation of AZA methyl esters as artefacts during extraction and sample pre-treatment. A. spinosum cells were collected from bioreactor cultures using centrifugation or filtration. Different extraction procedures were evaluated for formation of methyl ester artefacts, yield, and matrix effects. Filtration of cultures using glass-fibre filters led to increased formation of methyl esters, and centrifugation is recommended for recovery of cells. The extraction solvent (methanol (MeOH), acetone, and acetonitrile (MeCN)) did not significantly affect the yield of AZAs as long as the organic content was 80% or higher. However, the use of MeOH as extraction solvent led to increased formation of methyl esters. AZA1 recovery over two successive extractions was 100% at the 95% confidence level for acetone and MeOH. In standard-addition experiments, no significant matrix effects were observed in extracts of A. spinosum or Azadinium obesum up to a sample size of 4.5 × 10(9) μm(3). Moreover, experiments carried out to clarify the formation and structure of methylated AZA analogues led to the description of two AZA methyl esters and to the correction of the chemical structures of AZAs29-32.
authors.affiliation: IFREMER, Laboratoire EMP/PHYC, Rue de l'Ile d'Yeu, 44311, Nantes, France. Thierry.Jauffrais@ifremer.fr
authors.forename: Thierry
authors.initials: T
authors.lastname: Jauffrais
authors.forename: Christine
authors.initials: C
authors.lastname: Herrenknecht
authors.forename: Véronique
authors.initials: V
authors.lastname: Séchet
authors.forename: Manoella
authors.initials: M
authors.lastname: Sibat
authors.forename: Urban
authors.initials: U
authors.lastname: Tillmann
authors.forename: Bernd
authors.initials: B
authors.lastname: Krock
authors.forename: Jane
authors.initials: J
authors.lastname: Kilcoyne
authors.forename: Christopher O
authors.initials: CO
authors.lastname: Miles
authors.forename: Pearse
authors.initials: P
authors.lastname: McCarron
authors.forename: Zouher
authors.initials: Z
authors.lastname: Amzil
authors.forename: Philipp
authors.initials: P
authors.lastname: Hess
mesh_terms: D000096:Acetone; D000097:Acetonitriles; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004141:Dinoflagellida / Q000737:chemistry*; D008387:Marine Toxins / Q000032:analysis*; D012997:Solvents; D013141:Spiro Compounds / Q000032:analysis*; D053719:Tandem Mass Spectrometry; D000095702:Polyether Toxins
chemical_list: D000096:Acetone; D000097:Acetonitriles; D008387:Marine Toxins; D012997:Solvents; D013141:Spiro Compounds; C406592:azaspiracid; D000095702:Polyether Toxins; C032159:acetonitrile