Lipophilic marine toxins

It has also been demonstrated that styrene—DVB copolymer resins Sepabeads SP825, Sepabeads SP850, Optipore L-493, Diaion HP-20, and Amberlite XAD-4, of which the first three have a surface area of 1000 m /g and might be attributed to hypercrosshnked sorbents, accumulate lipophilic marine toxins okadaic acid and dinophysistoxin-1 from Prorocentrum lima cultures [298]. The procedure developed in the study represents a simple and efficient method suitable for solid-phase adsorption toxin tracking in both cultural fiquids and natural waters. The toxins are eluted from the resins with methanol and subjected to LC-MS analysis. 

TABLE 15.6 Chemical Characteristics of Lipophilic Marine Toxins... 

Figure 15.1 shows two chromatograms for lipophilic marine toxins. These analyses were performed using a typical LC—MS/MS method that employs an acid mobile phase. The sample analyzed was a mixture of... 

TABLE 15.7 Main Characteristics of the Liquid-Chromatography Method for Lipophilic Marine Toxin Detection... 

Gerssen A, van Olst EH, Mulder PP, de Boer J. In-house validation of a liquid chromatography tandem mass spectrometry method for the analysis of lipophilic marine toxins in shellfish using matrix-matched calibration. Anal Bioanal Chem 2010 397 3079-88. 

Fux E, McMillan D, Bire R, Hess P. Development of an ultra-performance liquid chromatography—mass spedrometry method for the detection of lipophilic marine toxins. J Chromatogr A 2007 1157 273-80. 

In 2005, the EU Commission and the Community Reference Laboratory on Marine Biotoxins appointed another Working Group on Toxicology to give further advice on risk assessment of lipophilic marine algal toxins in bivalves [4]. 

Lipophilic bioassay does not allow quantification, and it is very slow (24 h observation time), and several nontoxic/ nonregulated marine toxins may give false positives (spiroUdes, gynuiodimine, etc.)... 

Quilliam, M. A. (2003) Chemical methods for lipophilic shellfish toxins. In Manual on Harmful Marine Microalgae. G. M. Hallegraeff, D. M. Anderson, and A. D. Cembella (Eds.), UNESCO, Paris, France, pp. 211-245. 

Aasen, 1., Torgersen, T., and Anne, T., Application of an improved method for detection of lipophilic marine algal toxins (OA/DTXs, PTXs, YTXs and AZAs) with LC/MS, in Molluscan Shellfish Safety, Villalba, A., Reguera, B., Romalde, I.L., and Beiras, R. Eds., Intergovernmental Oceanographic Commission of UNESCO, Paris, 2003,49. 

Although the number of marine toxins is rather large, and their classification from a chemical point of view is potentially very complex, it is rather common to simply classify them as lipophilic and hydrophilic. Nevertheless, this division based on physicochemical criteria is not very useful, and it comes historically from the need to imderstand how they will be extracted to monitor their presence by the mouse bioassay. 

Lopez-Rivera, A., O Callaghan, K., Moriarty, M., O Driscoll, D., Hamilton, B., Lehane, M., James, K. and Furey, A. (2010) First evidence of azaspiracids (AZAs) A family of lipophilic polyether marine toxins in scallops Argopecten purpuratus) and mussels (Mytilus chilensis) collected in two regions of Chile. Toxicon, 55, 692-701. 

In order for allelochemicals to enter the body of a herbivore, absorption must occur across the gut lining. Curtailing the initial absorption of dietary allelochemicals may be a herbivore s first line of defense against plant toxins. Studies have citied the lack of absorption or metabolism of lipophilic plant secondary metabolites (i.e., terpenes), conducive to phase I or II detoxification, in the gut of terrestrial herbivores rather these compounds are excreted unchanged in the feces (Marsh et al. 2006b). While physical barriers or surfactants have been used to explain this limited adsorption in both marine and terrestrial herbivores (Lehane 1997 Barbehenn and Martin 1998 Barbehenn 2001 for review of marine herbivores, see Targett and Arnold 2001), active efflux of plant allelochemicals out of enterocytes into the gut lumen has received limited attention until now. 

Gerssen A, Mulder PP, McElhinney MA, de Boer J. Liquid chromatography-tandem mass spectrometry method for the detection of marine lipophilic toxins under alkaline conditions. J Chromatogr A 2009 1216 1421-30. 

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