Philipp Hess - Academia.edu (original) (raw)

Papers by Philipp Hess

Toxins

Algal toxins pose a serious threat to human and coastal ecosystem health, even if their potential... more Algal toxins pose a serious threat to human and coastal ecosystem health, even if their potential impacts are poorly documented in New Caledonia (NC). In this survey, bivalves and seawater (concentrated through passive samplers) from bays surrounding Noumea, NC, collected during the warm and cold seasons were analyzed for algal toxins using a multi-toxin screening approach. Several groups of marine microalgal toxins were detected for the first time in NC. Okadaic acid (OA), azaspiracid-2 (AZA2), pectenotoxin-2 (PTX2), pinnatoxin-G (PnTX-G), and homo-yessotoxin (homo-YTX) were detected in seawater at higher levels during the summer. A more diversified toxin profile was found in shellfish with brevetoxin-3 (BTX3), gymnodimine-A (GYM-A), and 13-desmethyl spirolide-C (SPX1), being confirmed in addition to the five toxin groups also found in seawater. Diarrhetic and neurotoxic toxins did not exceed regulatory limits, but PnTX-G was present at up to the limit of the threshold recommended ...

Journal of AOAC INTERNATIONAL, 2005

A method that uses liquid chromatography with tandem mass spectrometry (LC/MS/MS) has been develo... more A method that uses liquid chromatography with tandem mass spectrometry (LC/MS/MS) has been developed for the highly sensitive and specific determination of amnesic shellfish poisoning toxins, diarrhetic shellfish poisoning toxins, and other lipophilic algal toxins and metabolites in shellfish. The method was subjected to a full single-laboratory validation and a limited interlaboratory study. Tissue homogenates are blended with methanol-water (9 + 1), and the centrifuged extract is cleaned up with a hexane wash. LC/MS/MS (triple quadrupole) is used for quantitative analysis with reversed-phase gradient elution (acidic buffer), electrospray ionization (positive and negative ion switching), and multiple-reaction monitoring. Ester forms of dinophysis toxins are detected as the parent toxins after hydrolysis of the methanolic extract. The method is quantitative for 6 key toxins when reference standards are available: azaspiracid-1 (AZA1), domoic acid (DA), gymnodimine (GYM), okadaic aci...

Toxicology Letters, 2018

Azaspiracids (AZAs) are marine algal toxins that can be accumulated by edible shellfish to cause ... more Azaspiracids (AZAs) are marine algal toxins that can be accumulated by edible shellfish to cause a foodborne gastrointestinal poisoning in humans. In the European Union, only AZA1, −2 and −3 are currently regulated and their concentration in shellfish is determined through their toxic equivalency factors (TEFs) derived from the intraperitoneal lethal potency in mice. Nevertheless, considering the potential human exposure by oral route, AZAs TEFs should be calculated by comparative oral toxicity data. Thus, the acute oral toxicity of AZA1, −2 and −3 was investigated in female CD-1 mice treated with different doses (AZA1: 135-1100 μg/kg; AZA2 and AZA3: 300-1100 μg/kg) and sacrificed after 24 h or 14 days. TEFs derived from the median lethal doses (LD 50) were 1.0, 0.7 and 0.5, respectively for AZA1, −2 and −3. In fact, after 24 h from gavage administration, LD 50s were 443 μg/kg (AZA1; 95% CL: 350−561 μg/kg), 626 μg/kg (AZA2; 95% CL: 430−911 μg/kg) and 875 μg/kg (AZA3; 95% CL: 757−1010 μg/kg). Mice dead more than 5 h after the treatment or those sacrificed after 24 h (doses: ≥175 μg AZA1/kg, ≥500 μg AZA2/kg and ≥600 μg AZA3/kg) showed enlarged pale liver, while increased serum markers of liver alteration were recorded even at the lowest doses. Blood chemistry revealed significantly increased serum levels of K + ions (≥500 mg/kg), whereas light microscopy showed tissue changes in the gastrointestinal tract, liver and spleen. No lethality, macroscopic, tissue or haematological changes were recorded two weeks post exposure, indicating reversible toxic effects. LC-MS/MS analysis of the main organs showed a dose-dependency in gastrointestinal absorption of these toxins: at 24 h, the highest levels were detected in the stomach and, in descending order, in the intestinal content, liver, small intestine, kidneys, lungs, large intestine, heart as well as detectable traces in the brain. After 14 days, AZA1 and AZA2 were still detectable in almost all the organs and intestinal content.

Marine Drugs, 2019

Background: Azaspiracids (AZAs) are marine toxins that are produced by Azadinium and Amphidoma di... more Background: Azaspiracids (AZAs) are marine toxins that are produced by Azadinium and Amphidoma dinoflagellates that can contaminate edible shellfish inducing a foodborne poisoning in humans, which is characterized by gastrointestinal symptoms. Among these, AZA1, -2, and -3 are regulated in the European Union, being the most important in terms of occurrence and toxicity. In vivo studies in mice showed that, in addition to gastrointestinal effects, AZA1 induces liver alterations that are visible as a swollen organ, with the presence of hepatocellular fat droplets and vacuoles. Hence, an in vitro study was carried out to investigate the effects of AZA1, -2, and -3 on liver cells, using human non-tumor IHH hepatocytes. Results: The exposure of IHH cells to AZA1, -2, or -3 (5 × 10−12–1 × 10−7 M) for 24 h did not affect the cell viability and proliferation (Sulforhodamine B assay and 3H-Thymidine incorporation assay), but they induced a significant concentration-dependent increase of mito...

Rapid communications in mass spectrometry : RCM, Jan 5, 2017

Accurate quantitative analysis of lipophilic toxins by liquid chromatography-mass spectrometry (L... more Accurate quantitative analysis of lipophilic toxins by liquid chromatography-mass spectrometry (LC-MS) requires calibration solution reference materials (RMs) for individual toxin analogs. Untargeted analysis is aimed at identifying a vast number of compounds and thus validation of fully quantitative untargeted methods is not feasible. However, a semi-quantitative approach allowing for profiling is still required and will be strengthened by knowledge of the relative molar response (RMR) of analogs in liquid chromatography-mass spectrometry (LC-MS) with electrospray ionization (ESI). RMR factors were evaluated for toxins from the okadaic acid (OA/DTXs), yessotoxin (YTX), pectenotoxin (PTX), azaspiracid (AZA) and cyclic imine (CI) toxin groups, in both solvent standards and environmental sample extracts. Since compound ionization and fragmentation influences the MS response of toxins, RMRs were assessed under different chromatographic conditions (gradient, isocratic) and MS acquisitio...

Trends in Food Science & Technology, 2017

Background Seafood toxins pose an important risk to human health, and maximum levels were imposed... more Background Seafood toxins pose an important risk to human health, and maximum levels were imposed by regulatory authorities throughout the world. Several toxin groups are known, each one with many analogues of the major toxin. Regulatory limits are set to ensure that commercially available seafood is not contaminated with unsafe levels. Scope and Approach The mouse bioassay was used to measure the toxicity in seafood extracts to determine if a sample exceeded regulatory limits. The advantage of this approach was to provide an estimation of the total toxicity in the sample. As instrumental methods of analysis advance and serve as replacements to the mouse bioassay, the challenge is translating individual toxin concentrations into toxicity to determine whether regulatory limits have been exceeded. Such analyses provide accurate quantitation of the toxin Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site. analogues, by they have widely dissimilar potencies. Thus, knowledge of the relative toxicities is required for risk assessment and determining overall toxicity. The ratios between the toxicity of the analogues and that of a reference compound within the same toxin group are termed "Toxicity Equivalency Factors" (TEFs). Key Findings and Conclusions In this document, the requirements for determining TEFs of toxin analogues are described, and recommendations for research to further refine TEFs are identified. The proposed TEFs herein, when applied to toxin analogue concentrations determined using analytical methods, will provide a base to determine overall toxicity, thereby protecting human health. Highlights ► Marine toxins TEF are revised according to recent toxicology studies. ► TEF for each toxin group are proposed. ► The proposed TEF were agreed by a joint FAO-WHO working group.

Journal of agricultural and food chemistry, Jan 30, 2015

Azaspiracids (AZAs) are marine biotoxins that induce human illness following the consumption of c... more Azaspiracids (AZAs) are marine biotoxins that induce human illness following the consumption of contaminated shellfish. European Union regulation stipulates that only raw shellfish are tested, yet shellfish are often cooked prior to consumption. Analysis of raw and heat-treated mussels (Mytilus edulis) naturally contaminated with AZAs revealed significant differences (up to 4.6-fold) in AZA1-3 (1-3) and 6 (6) values due to heat-induced chemical conversions. Consistent with previous studies, high levels of 3 and 6 were detected in some samples that were otherwise below the limit of quantitation before heating. Relative to 1, in heat-treated mussels the average (n = 40) levels of 3 (range, 11-502%) and 6 (range, 3-170%) were 62 and 31%, respectively. AZA4 (4) (range, <1-27%), AZA5 (5) (range, 1-21%), and AZA8 (8) (range, 1-27%) were each ∼5%, whereas AZA7 (7), AZA9 (9), and AZA10 (10) (range, <1-8%) were each under 1.5%. Levels of 5, 10, AZA13 (13), and AZA15 (15) increased afte...

Marine and Freshwater Toxins, 2015

Azaspiracids (AZAs) are a toxin group that originate from marine dinoflagellates of the genera Az... more Azaspiracids (AZAs) are a toxin group that originate from marine dinoflagellates of the genera Azadinium and Amphidoma. After accumulation of these toxins in edible marine organisms and their subsequent consumption, humans develop a gastrointestinal syndrome referred to as azaspiracid shellfish poisoning (AZP). This syndrome is very similar to diarrheic shellfish poisoning (DSP), with main symptoms appearing after a few hours from consumption and including diarrhea, vomiting, and stomach cramps. Due to extensive metabolism in shellfish, more than 30 analogues have been reported to date, and purified compounds for selected analogues have recently been made available for toxicological studies. Currently, only AZA1, AZA2, and AZA3 are regulated in Europe and internationally; however, more recent evidence suggests that AZA6, AZA17, and AZA19 may also be analogues of importance for estimating the full risk of seafood. Even though animal studies have pointed out target organs (digestive tract, liver, heart, and lung), mechanism of action studies at cellular level are not yet conclusive. While a number of common targets have been excluded (protein phosphatases, kinases, actin depolymerization, G proteincoupled receptors), some evidence points toward ion channel activity of AZAs. Still, in vitro studies do not correlate well with symptoms observed in humans. Also, while some animal studies point toward longer-term effects, no such evidence has been reported from human poisoning events. However, it should be noted that in-depth epidemiological studies are still lacking. Even though all risk assessments have based their evaluation on a single, relatively early poisoning event in 1997, in Arranmore Island, Ireland, producing organisms and toxin occurrences have been reported worldwide, and further occurrence studies should provide a better base for such epidemiological studies.

Journal of Chromatography A, 2015

Measurement of marine algal toxins has traditionally focussed on shellfish monitoring while, over... more Measurement of marine algal toxins has traditionally focussed on shellfish monitoring while, over the last decade, passive sampling has been introduced as a complementary tool for exploratory studies. Since 2011, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been adopted as the EU reference method (No. 15/2011) for detection and quantitation of lipophilic toxins. Traditional LC-MS approaches have been based on low-resolution mass spectrometry (LRMS), however, advances in instrument platforms have led to a heightened interest in the use of high-resolution mass spectrometry (HRMS) for toxin detection. This work describes the use of HRMS in combination with passive sampling as a progressive approach to marine algal toxin surveys. Experiments focused on comparison of LRMS and HRMS for determination of a broad range of toxins in shellfish and passive samplers. Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site. approach. Limits of detection and method accuracy were comparable between the systems tested, demonstrating the applicability of HRMS as an effective tool for screening and quantitative analysis. HRMS offers the advantage of untargeted analysis, meaning that datasets can be retrospectively analyzed. HRMS (full scan) chromatograms of passive samplers yielded significantly less complex data sets than mussels, and were thus more easily screened for unknowns. Consequently, we recommend the use of HRMS in combination with passive sampling for studies investigating emerging or hitherto uncharacterized toxins. Highlights ► Quantitative HRMS-method developed for targeted screening of biotoxins. ► Advantage of HRMS over LRMS with regards to untargeted screening of unknowns. ► Similar magnitude and direction of matrix effects in HRMS compared to LRMS. ► Less matrix effects with passive sampler matrix compared to mussel matrix.

Journal of Agricultural and Food Chemistry, 2015

Azaspiracids (AZAs) are marine biotoxins produced by dinoflagellates that can accumulate in shell... more Azaspiracids (AZAs) are marine biotoxins produced by dinoflagellates that can accumulate in shellfish, which if consumed can lead to poisoning events. AZA7-10, 7-10, were isolated from shellfish and their structures, previously proposed on the basis of only LC-MS/MS data, were confirmed by NMR spectroscopy. Purified AZA4-6, 4-6, and 7-10 were accurately quantitated by qNMR and used to assay cytotoxicity with Jurkat T lymphocyte cells for the first time. LC-MS(MS) molar response studies performed using isocratic and gradient elution in both selected ion monitoring and selected reaction monitoring modes showed that responses for the analogues ranged from 0.3 to 1.2 relative to AZA1, 1. All AZA analogues tested were cytotoxic to Jurkat T lymphocyte cells in a time-and concentrationdependent manner; however, there were distinct differences in their EC50 values, with the potencies for each analogue being: AZA6 > AZA8 > AZA1 > AZA4 ≈ AZA9 > AZA5 ≈ AZA10. This data contributes to the understanding of the structure-activity relationships of AZAs. Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site.

 Management of department (36 permanent staff, 19 contractors & students)  Scientific & admin... more  Management of department (36 permanent staff, 19 contractors & students)  Scientific & administrative direction of 2 research laboratories & the national reference laboratory for microbiology of shellfish  Conduct research & provide expertise in the areas of shellfish safety, natural products chemistry, marine biotoxins & microorganisms, biodiscovery, risk characterization & evaluation Ma 2001-Sep2008 Team Leader, Marine Institute, Galway, Ireland  « Technical Manager », specified role in formal quality control management (ISO 17025)  Accreditation of all marine biotoxin methods used in official control in Ireland (ISO 17025)  Management of routine analytical unit (6-8 technicians and attendants), over 4000 test per annum (DA, OA, AZA, PSPs)  Management of research unit (supervision of 5-7 students & a postdoc  Responsible for all chemical activities of the Irish National Reference Laboratory for marine biotoxins, research projects and commercial services (see project management)  Responsible for scientific reports and publications (see list of publications, separate document)

The Marine Institute is the national agency which has the following functions: "to undertake, to ... more The Marine Institute is the national agency which has the following functions: "to undertake, to coordinate , to promote and to assist in marine research and development and to provide such services related to research and development that, in the opinion of the Institute, will promote economic development and create employment and protect the marine environment" Marine Institute Act 1991.

Molluscan Shellfish Safety, 2013

Azadinium spinosum, a small dinoflagellate has recently been discovered and identified as the pri... more Azadinium spinosum, a small dinoflagellate has recently been discovered and identified as the primary producer of azaspiracid-1 (AZA) and-2. Since AZA poisoning has been reported following consumption of contaminated shellfish it is important to have these toxins available for toxicological studies, and a sustainable production of AZAs as calibrants in monitoring programs without having to rely on natural events. In order to address this concern, continuous pilot scale cultures were carried out to evaluate the feasibility of AZA production from A. spinosum. Algae were cultured using two 100 L chemostats in series (R1 and R2), with agitation and pH control. Four different dilution rates were tested (0.15, 0.2, 0.25 and 0.3 day −1) to evaluate chemostat bioreactors in terms of cell and toxin productivity. Algae were collected in a 300 L transparent cylindro-conical tank and harvested with a tangential flow filtration device. Subsequently, toxins were extracted from the algal retentate and separately from the permeate using solid phase adsorption procedures. The cell concentration at steady state remained stable using different dilution rates (190,000 and 210,000 cells • mL −1 in R1 and R2 respectively). However, the AZA cell quota decreased as the dilution rate increased, consequently an optimum production was obtained at 0.25 day −1 under the studied conditions. After filtration, 50-70 % of the toxin was contained in the retentate and 30-50 % was released into the permeate. After optimization, the procedures for solid phase extraction of toxins from the retentate and permeate allowed for the recovery of 80 ± 5 % of original toxins produced. This work demonstrated the feasibility of producing AZAs from A. spinosum produced in a bioreactor for purification and production of certified standards.

Toxicon, 2008

Using high performance liquid chromatography with mass spectrometry the influence of conventional... more Using high performance liquid chromatography with mass spectrometry the influence of conventional steaming and other heat treatments on the level of azaspiracids, okadaic acid and dinophysistoxin-2 in mussels (Mytilus edulis) was investigated. A prior study looking at the influence of steaming on the concentration and distribution of azaspiracids showed significant increases in concentration as a result. Described is a follow-up study using two separate mussel samples, where the contribution of water loss during steaming to increases of toxin levels was examined. In addition to water loss it was demonstrated that heating of fresh azaspiracid contaminated mussels resulted in significant increases in the quantity of the desmethyl analogue (azaspiracid-3) measured. A systematic heat treatment experiment confirmed these findings and showed that azaspiracid-3 was the most thermally instable of the three regulated azaspiracid analogues. In parallel, the same studies were carried out for okadaic acid and dinophysistoxin-2 also naturally present in the samples used. Concentration increases correlated with water loss during steaming. More so than for azaspiracids, increased distribution of okadaic acid and dinophysistoxin-2 from the digestive glands to the remainder tissues was observed as a result of the processes examined. This suggests that analysis of whole flesh tissues, as opposed to dissected digestive glands, is more appropriate for regulatory purposes, particularly if cooked samples are being analysed. The findings of the studies reported here have importance in terms of the methodology applied in regulatory phycotoxin monitoring programmes. Therefore, options for sample pre-treatment are discussed.

Toxicon, 2012

Azadinium spinosum (Elbrächter and Tillmann), a small marine dinoflagellate, has been recently de... more Azadinium spinosum (Elbrächter and Tillmann), a small marine dinoflagellate, has been recently described as a de novo producer of azaspiracid-1 and-2 (AZA1 and-2) diarrhoeic toxins. A culture of A. spinosum was established in our laboratory and optimised for pilot-scale production of this organism, to evaluate and understand AZA1 and-2 accumulation and biotransformation in blue mussels (Mytilus edulis) fed with A. spinosum. Adult mussels were continuously exposed to A. spinosum over 1 week in 160 L cylindrical conical tanks. Three different diets were tested for contamination: 5000, 10 000 cells mL −1 of A. spinosum and a mixture of 5000 cells mL −1 of A. spinosum with 5000 cells mL −1 of Isochrysis aff. galbana (T-Iso, CCAP 927/14). During the subsequent period of detoxification (2 weeks), contaminated mussels were continuously fed with 5000 cells mL −1 of T-Iso. Kinetics of accumulation, detoxification and biotransformation were evaluated, as well as the toxin distribution and the effect of A. spinosum on mussel digestive gland tubules. Highlights ► Azadinium spinosum was cultured and fed to blue mussels (Mytilus edulis). ► Mussels accumulated azaspiracids in less than 6 h to greater than legal limit. ► Biotransformation of algal toxins into shellfish metabolites was also rapid with >25% metabolites observed after 6 h. ► Detoxification speed was comparable with other lipophilic toxins (half-life ca. 11 days). ► Azaspiracids-6,-17 and-19 should also be considered in legislation.

Analytical and bioanalytical chemistry, Jan 22, 2014

Azaspiracids (AZAs) are lipophilic biotoxins produced by marine algae that can contaminate shellf... more Azaspiracids (AZAs) are lipophilic biotoxins produced by marine algae that can contaminate shellfish and cause human illness. The European Union (EU) regulates the level of AZAs in shellfish destined for the commercial market, with liquid chromatography-mass spectrometry (LC-MS) being used as the official reference method for regulatory analysis. Certified reference materials (CRMs) are essential tools for the development, validation, and quality control of LC-MS methods. This paper describes the work that went into the planning, preparation, characterization, and certification of CRM-AZA-Mus, a tissue matrix CRM, which was prepared as a wet homogenate from mussels (Mytilus edulis) naturally contaminated with AZAs. The homogeneity and stability of CRM-AZA-Mus were evaluated, and the CRM was found to be fit for purpose. Extraction and LC-MS/MS methods were developed to accurately certify the concentrations of AZA1 (1.16 mg/kg), AZA2 (0.27 mg/kg), and AZA3 (0.21 mg/kg) in the CRM. Qua...

Toxicon, 2014

Marine biotoxins are algal metabolites that can accumulate in fish or shellfish and render these ... more Marine biotoxins are algal metabolites that can accumulate in fish or shellfish and render these foodstuffs unfit for human consumption. These toxins, released into seawater during algal occurrences, can be monitored through passive sampling. Acetone, methanol and isopropanol were evaluated for their efficiency in extracting toxins from algal biomass. Isopropanol was chosen for further experiments thanks to a slightly higher recovery and no artifact formation. Comparison of Oasis HLB, Strata-X, BondElut C18 and HP-20 sorbent materials in SPE-mode led to the choice of Oasis HLB, HP-20 and Strata-X. These three sorbents were separately exposed as passive samplers for 24 h to seawater spiked with algal extracts containing known amounts of okadaic acid (OA), azaspiracids (AZAs), pinnatoxin-G (PnTX-G), 13-desmethyl spirolide-C (SPX1) and palytoxins (PlTXs). Low density polyethylene (LDPE) and silicone rubber (PDMS) strips were tested in parallel on similar mixtures of spiked natural seawater for 24 h. These strips gave significantly lower recoveries than the polymeric sorbents. Irrespective of the toxin group, the adsorption rate of toxins on HP-20 was slower than on Oasis HLB and Strata-X. However, HP-20 and Strata-X gave somewhat higher recoveries after 24 h exposure. Irrespective of the sorbent tested, recoveries were generally highest for cyclic imines and OA group toxins, slightly lower for AZAs, and the lowest for palytoxins. Trials in re-circulated closed tanks with mussels exposed to Vulcanodinium rugosum or Prorocentrum lima allowed for further evaluation of passive samplers. In these experiments with different sorbent materials competing for toxins in the same container, Strata-X accumulated toxins faster than Oasis HLB, and HP-20, and to higher levels. The deployment of these three sorbents at Ingril French Mediterranean lagoon to detect PnTX-G in the water column showed accumulation of higher levels on HP-20 and Oasis HLB compared to Strata-X. This study has significantly extended the range of sorbents for passive sampling of marine toxins. In particular, sorbents were included that had previously been evaluated for polyhalogenated Highlights ► First use of Strata-X, Oasis HLB, LDPE and PDMS as passive samplers for many toxins. ► Passive sampling of Ovatoxin-a was possible in laboratory trials. ►Presence of Prorocentrum lima indicated through passive sampling.► Toxins from benthic algae detected with passive samplers. ► HP-20 most appropriate for long exposure periods (>5 days).

Toxicon, 2013

The relationship between azaspiracid shellfish poisoning and a small dinoflagellate, Azadinium sp... more The relationship between azaspiracid shellfish poisoning and a small dinoflagellate, Azadinium spinosum, has been shown recently. The organism produces AZA1 and-2, while AZA3 and other analogues are metabolic products formed in shellfish. We evaluated whether mussels were capable of accumulating dissolved AZA1 and-2, and compared the toxin profiles of these mussels at 24 h with profiles of those exposed to live or lysed A. spinosum. We also assessed the possibility of preparative production of AZA metabolites by exposing mussels to semi-purified AZA1. We exposed mussels to similar concentration of AZAs: dissolved AZA1 + 2 (crude extract) at 7.5 and 0.75 μg L −1 , dissolved AZA1+2 (7.5 μg L −1) in combination with Isochrysis affinis galbana, and lysed and live A. spinosum cells at 1 × 10 5 and 1 × 10 4 cell mL −1 (containing equivalent amounts of AZA1 + 2). Subsequently, we dissected and analysed digestive glands, gills and remaining flesh. Mussels (whole flesh) accumulated AZAs to levels above the regulatory limit, except at the lower levels of dissolved AZAs. The toxin profile of the mussels varied significantly with treatment. The gills contained 42-46% and the digestive glands 23-24% of the total toxin load using dissolved AZAs, compared to 3-12% and 75-90%, respectively, in mussels exposed to live A. spinosum. Exposure of mussels to semi-purified AZA1 produced the metabolites AZA17 (16.5%) and AZA3 (1.7%) after 4 days of exposure, but the conversion efficiency was too low to justify using this procedure for preparative isolation. Highlights ► Blue mussels were exposed to dissolved AZAs, live and lysed Azadinium spinosum. ► Mussels accumulated dissolved AZAs to greater than legal limit. ► Biotransformation of algal toxins into shellfish metabolites was observed. ► Mussels accumulate AZAs mainly in gills when AZAs are dissolved. ► Mussels accumulate AZAs mainly in digestive glands when fed A. spinosum.

Marine Drugs, 2008

Azaspiracids (AZA) are polyether marine toxins that accumulate in various shellfish species and h... more Azaspiracids (AZA) are polyether marine toxins that accumulate in various shellfish species and have been associated with severe gastrointestinal human intoxications since 1995. This toxin class has since been reported from several countries, including Morocco and much of western Europe. A regulatory limit of 160 µg AZA/kg whole shellfish flesh was established by the EU in order to protect human health; however, in some cases, AZA concentrations far exceed the action level. Herein we discuss recent advances on the chemistry of various AZA analogs, review the ecology of AZAs, including the putative progenitor algal species, collectively interpret the in vitro and in vivo data on the toxicology of AZAs relating to human health issues, and outline the European legislature associated with AZAs.