Detection of five new hydroxyl analogues of azaspiracids in shellfish using multiple tandem mass spectrometry.
The polyether dinoflagellate toxins, azaspiracids, are responsible for azaspiracid poisoning (AZP), a new human toxic syndrome arising from the consumption of shellfish. To date, five azaspiracids have been isolated and fully structurally elucidated, including, AZA1, its 8-methyl and 22-demethyl analogues, AZA2 and AZA3, respectively, and two hydroxyl derivatives of AZA3, named AZA4 and AZA5. Using a recently developed method involving liquid chromatography with multiple tandem mass spectrometry (LC-MS(n)), five new azaspiracids, AZA7-AZA11, have been found in mussels (Mytilus edulis). AZA6 is a positional isomer of AZA1 and four of the new compounds are isomers with a mass of 857.5 amu. AZA7 and AZA8 are hydroxyl analogues of AZA1 while AZA9 and AZA10 are hydroxyl analogues of AZA6. AZA11 is a hydroxyl analogue of AZA2. The separation of all 11 azaspiracids was achieved using isocratic reversed phase liquid chromatography using a combination of eluent additives, trifluoroacetic acid and ammonium acetate. The ion-trap MS experiments, with electrospray ionisation, involved the fragmentation of the protonated molecule [M+H](+), trapping and fragmenting the product ions due to the loss of a water molecule [M+H-H(2)O](+), together with mass spectral data analysis that included the characteristic A-ring fragmentation for each compound.
James
Kevin J
KJ
PROTEOBIO, Department of Chemistry, Mass Spectrometry Centre for Proteomics and Biotoxin Research, Cork Institute of Technology, Bishopstown, Cork, Ireland. kjames@cit.ie
Sierra
Monica Diaz
MD
Lehane
Mary
M
Braña Magdalena
Ana
A
Furey
Ambrose
A
D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D005517:Foodborne Diseases; D008387:Marine Toxins / Q000032:analysis* / Q000145:classification; D012758:Shellfish / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013141:Spiro Compounds / Q000032:analysis* / Q000145:classification; D000095702:Polyether Toxins
D008387:Marine Toxins; D013141:Spiro Compounds; C406592:azaspiracid; D000095702:Polyether Toxins