| Abstract | Special issue of 21st Meeting of the French-Society-of-Toxicology (SFET) Azaspiracids (AZAs) were discovered following a poisoning event in the Netherlands in 1995 after people consumed contaminated shellfish harvested in Ireland. The symptoms included nausea, vomiting, diarrhea, and stomach cramps. AZA1, -2 and -3 were identified as the source of the illnesses. LC MS/MS is the EU reference method for detection of AZAs, with the regulatory limit set at 160 μg/kg AZA1 equivalents. Extensive research has revealed that more than 20 additional AZA analogues exist. The phytoplankton Azadinium spinosum produces AZA1 and -2 while AZA3 and many of the other analogues are metabolic products formed in the shellfish. To date AZA1-6 have been isolated, chemically characterized and assessed for their toxicological impact using both in vitro and in vivo assays. Cytotoxicity studies indicate that AZA1, -2, and -3 elicit a lethal response that is both concentration- and time- dependent, with EC50 values in the sub- to low nanomolar range. The availability of as many AZA analogues as possible, in sufficient quantity and purity, is imperative to highlight the analogues which are relevant for public health protection. Here we describe efforts made to identify hitherto unknown analogues of the AZA group in phytoplankton and shellfish as well as attempts to isolate some of the known minor AZA analogues using a series of partitioning and column chromatography steps. Samples were purified in sufficient quantities to enable full structural elucidation by LC-MS/MS and NMR and toxicological assessment using the Jurkat T lymphocyte cell assay. Some the purified compounds had significant differences in their structure from the main AZA analogues which enabled examination of structure-activity relationships. |
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