title: Complex toxin profiles in phytoplankton and Greenshell mussels (Perna canaliculus), revealed by LC-MS/MS analysis.
abstract: Toxin profiles were determined in phytoplankton cell concentrates and Greenshell mussels (Perna canaliculus) exposed to a dinoflagellate bloom dominated by Dinophysis acuta and Protoceratium reticulatum. This was achieved by using a method for the simultaneous identification and quantification of a variety of micro-algal toxins by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionisation (+/-) and monitoring of daughter ions in multiple reaction modes. Plankton concentrates and shellfish contained high levels of yessotoxins (YTXs) and pectenotoxins (PTXs) and low levels of okadaic acid (OA). A high proportion (>87%) of the OA in both plankton and shellfish was released by alkaline hydrolysis. An isomer of pectenotoxin 1 (PTX1i) was nearly as abundant as pectenotoxin 2 (PTX2) in the plankton and shellfish, and the latter contained high levels of their respective seco acids. DTX1, DTX2, and PTX6 were not detected. MS-MS experiments revealed that the shellfish contained several other oxygenated metabolites of YTX in addition to 45-hydroxy yessotoxin (45OH-YTX). Gymnodimine (GYM) was present in the shellfish but not plankton and it was probably the residue from a previous GYM contamination event. Unlike the other toxins, GYM was concentrated in tissues outside the digestive gland and levels did not decrease over 5 months. The depuration rates of YTX and PTXs from mussels were modelled.
authors.affiliation: Cawthron Institute, 98 Halifax Street, Private Bag 2, Nelson, New Zealand. lincoln@cawthron.org.nz
authors.forename: Lincoln
authors.initials: L
authors.lastname: MacKenzie
authors.forename: Patrick
authors.initials: P
authors.lastname: Holland
authors.forename: Paul
authors.initials: P
authors.lastname: McNabb
authors.forename: Veronica
authors.initials: V
authors.lastname: Beuzenberg
authors.forename: Andy
authors.initials: A
authors.lastname: Selwood
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000737:chemistry* / Q000378:metabolism; D002853:Chromatography, Liquid; D004141:Dinoflagellida / Q000737:chemistry* / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods; D004988:Ethers, Cyclic / Q000032:analysis / Q000378:metabolism; D005663:Furans / Q000032:analysis / Q000378:metabolism; D018942:Macrolides; D008387:Marine Toxins / Q000032:analysis* / Q000378:metabolism; D008978:Mollusk Venoms; D009520:New Zealand; D019319:Okadaic Acid / Q000032:analysis / Q000378:metabolism; D035964:Oxocins / Q000032:analysis / Q000378:metabolism; D010839:Phytoplankton / Q000737:chemistry* / Q000378:metabolism; D011714:Pyrans / Q000032:analysis / Q000378:metabolism; D012758:Shellfish / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization; D000095702:Polyether Toxins
chemical_list: D004988:Ethers, Cyclic; D005663:Furans; D018942:Macrolides; D008387:Marine Toxins; D008978:Mollusk Venoms; D019319:Okadaic Acid; D035964:Oxocins; D011714:Pyrans; C051905:pectenotoxin 1; D000095702:Polyether Toxins; C098380:pectenotoxin 2; C066632:yessotoxin