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Yang J, Sun W, Sun M, Cui Y, Wang L. Current Research Status of Azaspiracids. Mar Drugs 2024; 22:79. [PMID: 38393050 PMCID: PMC10890026 DOI: 10.3390/md22020079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
The presence and impact of toxins have been detected in various regions worldwide ever since the discovery of azaspiracids (AZAs) in 1995. These toxins have had detrimental effects on marine resource utilization, marine environmental protection, and fishery production. Over the course of more than two decades of research and development, scientists from all over the world have conducted comprehensive studies on the in vivo metabolism, in vitro synthesis methods, pathogenic mechanisms, and toxicology of these toxins. This paper aims to provide a systematic introduction to the discovery, distribution, pathogenic mechanism, in vivo biosynthesis, and in vitro artificial synthesis of AZA toxins. Additionally, it will summarize various detection methods employed over the past 20 years, along with their advantages and disadvantages. This effort will contribute to the future development of rapid detection technologies and the invention of detection devices for AZAs in marine environmental samples.
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Affiliation(s)
| | | | | | | | - Lianghua Wang
- Basic Medical College, Naval Medical University, Shanghai 200433, China; (J.Y.); (W.S.); (M.S.); (Y.C.)
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2
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Wright EJ, Meija J, McCarron P, Miles CO. Preparation of 18O-labelled azaspiracids for accurate quantitation using liquid chromatography-mass spectrometry. Anal Bioanal Chem 2023; 415:5973-5983. [PMID: 37530793 PMCID: PMC10556123 DOI: 10.1007/s00216-023-04868-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 08/03/2023]
Abstract
Azaspiracids (AZAs) are a group of polyether marine algal toxins known to accumulate in shellfish, posing a risk to human health and the seafood industry. Analysis of AZAs is typically performed using LC-MS, which can suffer from matrix effects that significantly impact the accuracy of measurement results. While the use of isotopic internal standards is an effective approach to correct for these effects, isotopically labelled standards for AZAs are not currently available. In this study, 18O-labelled AZA1, AZA2, and AZA3 were prepared by reaction with H218O under acidic conditions, and the reaction kinetics and sites of incorporation were studied using LC-HRMS/MS aided by mathematical analysis of their isotope patterns. Analysis of the isotopic incorporation in AZA1 and AZA3 indicated the presence of four exchangeable oxygen atoms. Excessive isomerization occurred during preparation of 18O-labelled AZA2, suggesting a role for the 8-methyl group in the thermodynamic stability of AZAs. Neutralized mixtures of 18O-labelled AZA1 and AZA3 were found to maintain their isotopic and isomeric integrities when stored at -20 °C and were used to develop an isotope-dilution LC-MS method which was applied to reference materials of shellfish matrices containing AZAs, demonstrating high accuracy and excellent reproducibility. Preparation of isotopically labelled compounds using the isotopic exchange method, combined with the kinetic analysis, offers a feasible way to obtain isotopically labelled internal standards for a wide variety of biomolecules to support reliable quantitation.
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Affiliation(s)
- Elliott J. Wright
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, NS B3H 3Z1 Canada
| | - Juris Meija
- National Research Council, 1200 Montreal Road, Ottawa, ON K1A 0R6 Canada
| | - Pearse McCarron
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, NS B3H 3Z1 Canada
| | - Christopher O. Miles
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, NS B3H 3Z1 Canada
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Salas R, Murphy E, Doohan R, Tillmann U, Thomas OP. Production of the dinoflagellate Amphidoma languida in a large scale photobioreactor and structure elucidation of its main metabolite AZA-39. HARMFUL ALGAE 2023; 127:102471. [PMID: 37544671 DOI: 10.1016/j.hal.2023.102471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/27/2023] [Accepted: 06/10/2023] [Indexed: 08/08/2023]
Abstract
Shellfish contamination with azaspiracids (AZA) is a major and recurrent problem for the Irish shellfish industry. Amphidoma languida, a small thecate dinoflagellate of the family Amphidomataceae, is widely distributed in Irish coastal waters and is one of the identified source species of azaspiracids. Irish and North Sea strains of Am. languida have been found to produce as major metabolites AZA-38 and -39 whose structures have only been provisionally elucidated by mass spectrometry and their toxic potential is currently unknown. In order to provide pure AZA-38 and -39 for subsequent structural and toxicological analyses, we present the first successful large-scale culture of Am. languida. A 180 L in house prototype bioreactor was used for culture growth and harvesting in semi-continuous mode for two months. Two different runs of the photobiorector with different light and pH setting showed the highest toxin yield at higher light intensity and slightly higher pH. AZA-38 and -39 cell quota were measured throughout the complete growth cycle with AZA-39 cell quota increasing in proportion to AZA-38 at late stationary to senescence phase. Over two experiments a total of 700 L of culture was harvested yielding 0.45 mg of pure AZA-39. The structure of AZA-39 was elucidated through NMR data analyses, which led to a revision of the structure proposed previously by mass spectrometry. While the spirotetrahydrofuran/tetrahydrofuran of rings A and B has been confirmed by NMR for AZA-39, a methyl is still present in position C-14 and the carboxylic acid chain is different from the structure proposed initially.
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Affiliation(s)
- Rafael Salas
- Marine Institute, Rinville, Oranmore, H91 R673, Co. Galway, Ireland.
| | - Elliot Murphy
- Marine Institute, Rinville, Oranmore, H91 R673, Co. Galway, Ireland; School of Biological and Chemical Sciences, Ryan Institute, University of Galway, University Road, H91TK33 Galway, Ireland
| | - Roisin Doohan
- School of Biological and Chemical Sciences, Ryan Institute, University of Galway, University Road, H91TK33 Galway, Ireland
| | - Urban Tillmann
- Alfred Wegener Institut-Helmholtz Zentrum für Polar- und Meeresforschung Am Handelshafen 12, D-27570 Bremerhaven, Germany
| | - Olivier P Thomas
- School of Biological and Chemical Sciences, Ryan Institute, University of Galway, University Road, H91TK33 Galway, Ireland
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Tebben J, Zurhelle C, Tubaro A, Samdal IA, Krock B, Kilcoyne J, Sosa S, Trainer VL, Deeds JR, Tillmann U. Structure and toxicity of AZA-59, an azaspiracid shellfish poisoning toxin produced by Azadinium poporum (Dinophyceae). HARMFUL ALGAE 2023; 124:102388. [PMID: 37164556 DOI: 10.1016/j.hal.2023.102388] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 05/12/2023]
Abstract
To date, the putative shellfish toxin azaspiracid 59 (AZA-59) produced by Azadinium poporum (Dinophyceae) has been the only AZA found in isolates from the Pacific Northwest coast of the USA (Northeast Pacific Ocean). Anecdotal reports of sporadic diarrhetic shellfish poisoning-like illness, with the absence of DSP toxin or Vibrio contamination, led to efforts to look for other potential toxins, such as AZAs, in water and shellfish from the region. A. poporum was found in Puget Sound and the outer coast of Washington State, USA, and a novel AZA (putative AZA-59) was detected in low quantities in SPATT resins and shellfish. Here, an A. poporum strain from Puget Sound was mass-cultured and AZA-59 was subsequently purified and structurally characterized. In vitro cytotoxicity of AZA-59 towards Jurkat T lymphocytes and acute intraperitoneal toxicity in mice in comparison to AZA-1 allowed the derivation of a provisional toxicity equivalency factor of 0.8 for AZA-59. Quantification of AZA-59 using ELISA and LC-MS/MS yielded reasonable quantitative results when AZA-1 was used as an external reference standard. This study assesses the toxic potency of AZA-59 and will inform guidelines for its potential monitoring in case of increasing toxin levels in edible shellfish.
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Affiliation(s)
- Jan Tebben
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Section Ecological Chemistry, Am Handelshafen 12, Bremerhaven, 27570, Germany.
| | - Christian Zurhelle
- University of Bremen, Department of Biology and Chemistry, Marine Chemistry, Leobener Straße 6, Bremen, 28359, Germany
| | - Aurelia Tubaro
- Department of Life Sciences, University of Trieste, Via A. Valerio 6, Trieste, 34127, Italy
| | | | - Bernd Krock
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Section Ecological Chemistry, Am Handelshafen 12, Bremerhaven, 27570, Germany
| | - Jane Kilcoyne
- Marine Institute, Rinville, Oranmore, County Galway H91 R673, Ireland
| | - Silvio Sosa
- Department of Life Sciences, University of Trieste, Via A. Valerio 6, Trieste, 34127, Italy
| | - Vera L Trainer
- Olympic Natural Resources Center, University of Washington, 1455 S. Forks Ave, Forks, WA 98331, United States
| | - Jonathan R Deeds
- Center for Food Safety and Applied Nutrition, Office of Regulatory Science, U.S. Food and Drug Administration, 5001 Campus Drive, College Park, Maryland, 20740, United States of America
| | - Urban Tillmann
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Section Ecological Chemistry, Am Handelshafen 12, Bremerhaven, 27570, Germany.
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Chen ZH, Guo YW, Li XW. Recent advances on marine mollusk-derived natural products: chemistry, chemical ecology and therapeutical potential. Nat Prod Rep 2023; 40:509-556. [PMID: 35942896 DOI: 10.1039/d2np00021k] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: 2011-2021Marine mollusks, which are well known as rich sources of diverse and biologically active natural products, have attracted significant attention from researchers due to their chemical and pharmacological properties. The occurrence of some of these marine mollusk-derived natural products in their preys, predators, and associated microorganisms has also gained interest in chemical ecology research. Based on previous reviews, herein, we present a comprehensive summary of the recent advances of interesting secondary metabolites from marine mollusks, focusing on their structural features, possible chemo-ecological significance, and promising biological activities, covering the literature from 2011 to 2021.
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Affiliation(s)
- Zi-Hui Chen
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China.
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
| | - Yue-Wei Guo
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China.
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, Yantai, Shandong 264117, China
| | - Xu-Wen Li
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China.
- University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China
- Shandong Laboratory of Yantai Drug Discovery, Bohai Rim Advanced Research Institute for Drug Discovery, Yantai, Shandong 264117, China
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Wright EJ, McCarron P. A mussel tissue certified reference material for multiple phycotoxins. Part 5: profiling by liquid chromatography-high-resolution mass spectrometry. Anal Bioanal Chem 2021; 413:2055-2069. [PMID: 33661347 DOI: 10.1007/s00216-020-03133-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/14/2020] [Accepted: 12/16/2020] [Indexed: 02/07/2023]
Abstract
A freeze-dried mussel tissue-certified reference material (CRM-FDMT1) was prepared containing the marine algal toxin classes azaspiracids, okadaic acid and dinophysistoxins, yessotoxins, pectenotoxins, cyclic imines, and domoic acid. Thus far, only a limited number of analogues in CRM-FDMT1 have been assigned certified values; however, the complete toxin profile is significantly more complex. Liquid chromatography-high-resolution mass spectrometry was used to profile CRM-FDMT1. Full-scan data was searched against a list of previously reported toxin analogues, and characteristic product ions extracted from all-ion-fragmentation data were used to guide the extent of toxin profiling. A series of targeted and untargeted acquisition MS/MS experiments were then used to collect spectra for analogues. A number of toxins previously reported in the literature but not readily available as standards were tentatively identified including dihydroxy and carboxyhydroxyyessotoxin, azaspiracids-33 and -39, sulfonated pectenotoxin analogues, spirolide variants, and fatty acid acyl esters of okadaic acid and pectenotoxins. Previously unreported toxins were also observed including compounds from the pectenotoxin, azaspiracid, yessotoxin, and spirolide classes. More than one hundred toxin analogues present in CRM-FDMT1 are summarized along with a demonstration of the major acyl ester conjugates of several toxins. Retention index values were assigned for all confirmed or tentatively identified analogues to help with qualitative identification of the broad range of lipophilic toxins present in the material.
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Affiliation(s)
- Elliott J Wright
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada
| | - Pearse McCarron
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada.
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Kilcoyne J, Burrell S, Nulty C, Salas R, Wright EJ, Rajotte I, Miles CO. Improved Isolation Procedures for Okadaic Acid Group Toxins from Shellfish ( Mytilus edulis) and Microalgae ( Prorocentrum lima). Mar Drugs 2020; 18:md18120647. [PMID: 33339248 PMCID: PMC7766028 DOI: 10.3390/md18120647] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/03/2020] [Accepted: 12/14/2020] [Indexed: 11/17/2022] Open
Abstract
Okadaic acid (OA) group toxins may accumulate in shellfish and can result in diarrhetic shellfish poisoning when consumed by humans, and are therefore regulated. Purified toxins are required for the production of certified reference materials used to accurately quantitate toxin levels in shellfish and water samples, and for other research purposes. An improved procedure was developed for the isolation of dinophysistoxin 2 (DTX2) from shellfish (M. edulis), reducing the number of purification steps from eight to five, thereby increasing recoveries to ~68%, compared to ~40% in a previously reported method, and a purity of >95%. Cell densities and toxin production were monitored in cultures of Prorocentrum lima, that produced OA, DTX1, and their esters, over ~1.5 years with maximum cell densities of ~70,000 cells mL−1 observed. Toxin accumulation progressively increased over the study period, to ~0.7 and 2.1 mg L−1 of OA and DTX1 (including their esters), respectively, providing information on appropriate harvesting times. A procedure for the purification of OA and DTX1 from the harvested biomass was developed employing four purification steps, with recoveries of ~76% and purities of >95% being achieved. Purities were confirmed by LC-HRMS, LC-UV, and NMR spectroscopy. Additional stability observations led to a better understanding of the chemistry of these toxins.
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Affiliation(s)
- Jane Kilcoyne
- Marine Institute, Rinville, Oranmore, Co. Galway H91 R673, Ireland; (S.B.); (C.N.); (R.S.)
- Correspondence: ; Tel.: +353-91387200
| | - Stephen Burrell
- Marine Institute, Rinville, Oranmore, Co. Galway H91 R673, Ireland; (S.B.); (C.N.); (R.S.)
| | - Cíara Nulty
- Marine Institute, Rinville, Oranmore, Co. Galway H91 R673, Ireland; (S.B.); (C.N.); (R.S.)
| | - Rafael Salas
- Marine Institute, Rinville, Oranmore, Co. Galway H91 R673, Ireland; (S.B.); (C.N.); (R.S.)
| | - Elliott J. Wright
- Biotoxin Metrology, National Research Council Canada, Halifax, NS B3H 3Z1, Canada; (E.J.W.); (I.R.); (C.O.M.)
| | - Isabelle Rajotte
- Biotoxin Metrology, National Research Council Canada, Halifax, NS B3H 3Z1, Canada; (E.J.W.); (I.R.); (C.O.M.)
| | - Christopher O. Miles
- Biotoxin Metrology, National Research Council Canada, Halifax, NS B3H 3Z1, Canada; (E.J.W.); (I.R.); (C.O.M.)
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Mudge EM, Miles CO, Hardstaff WR, McCarron P. Fatty acid esters of azaspiracids identified in mussels ( Mytilus edulis) using liquid chromatography-high resolution mass spectrometry. Toxicon X 2020; 8:100059. [PMID: 33073234 PMCID: PMC7549145 DOI: 10.1016/j.toxcx.2020.100059] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/25/2020] [Accepted: 09/25/2020] [Indexed: 12/02/2022] Open
Abstract
Azaspiracids (AZAs) are lipophilic polyether toxins produced by Azadinium and Amphidoma species of marine microalgae. The main dinoflagellate precursors AZA1 and AZA2 are metabolized by shellfish to produce an array of AZA analogues. Many marine toxins undergo fatty acid esterification in shellfish, therefore mussel tissues contaminated with AZAs were screened for intact fatty acid esters of AZAs using liquid chromatography-high resolution mass spectrometry. Acyl esters were primarily observed for AZAs containing hydroxy groups at C-3 with 3-O-palmitoylAZA4 identified as the most abundant acyl ester, while other fatty acid esters including 18:1, 16:1, 17:0, 20:2 and 18:0 acyl esters were detected. The structures of these acyl derivatives were determined through LC-MS/MS experiments, and supported by periodate cleavage reactions and semi-synthesis of palmitate esters of the AZAs. Esters of the hydroxy groups at C-20 or C-21 were not observed in mussel tissue. The relative proportion of the most abundant AZA ester was less than 3% of the sum of the major free AZA analogues. These findings reveal an additional metabolic pathway for AZAs in shellfish. Fatty acid esters of azaspiracids were identified in mussels (Mytilus edulis). Fatty acid esters of azaspiracids with hydroxy groups at C-3 were primarily observed. Fatty acid esters of regulated azaspiracids (AZA1, 2, −3) were absent. Structures were determined with LC-HRMS and confirmed by semi-synthesis of palmitate esters and periodate cleavage. This work reveals an additional metabolic pathway for azaspiracids in shellfish.
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Qiu J, Wright EJ, Thomas K, Li A, McCarron P, Beach DG. Semiquantitation of Paralytic Shellfish Toxins by Hydrophilic Interaction Liquid Chromatography-Mass Spectrometry Using Relative Molar Response Factors. Toxins (Basel) 2020; 12:toxins12060398. [PMID: 32560098 PMCID: PMC7354571 DOI: 10.3390/toxins12060398] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 06/10/2020] [Accepted: 06/12/2020] [Indexed: 12/30/2022] Open
Abstract
Paralytic shellfish toxins (PSTs) are a complex class of analogs of the potent neurotoxin saxitoxin (STX). Since calibration standards are not available for many PSTs, including C-11 hydroxyl analogs called M-toxins, accurate quantitation by liquid chromatography–mass spectrometry (LC-MS) can be challenging. In the absence of standards, PSTs are often semiquantitated using standards of a different analog (e.g., STX), an approach with a high degree of uncertainty due to the highly variable sensitivity between analytes in electrospray ionization. Here, relative molar response factors (RMRs) were investigated for a broad range of PSTs using common LC-MS approaches in order to improve the quantitation of PSTs for which standards are unavailable. First, several M-toxins (M1-M6, M9 and dcM6) were semipurified from shellfish using preparative gel filtration chromatography and quantitated using LC-charged aerosol detection (LC-CAD). The RMRs of PST certified reference materials (CRMs) and M-toxins were then determined using selective reaction monitoring LC-MS/MS and full scan LC-high-resolution MS (LC-HRMS) methods in positive and negative electrospray ionization. In general, RMRs for PSTs with similar chemical structures were comparable, but varied significantly between subclasses, with M-toxins showing the lowest sensitivity. For example, STX showed a greater than 50-fold higher RMR than M4 and M6 by LC-HRMS. The MS instrument, scan mode and polarity also had significant impacts on RMRs and should be carefully considered when semiquantitating PSTs by LC-MS. As a demonstration of their utility, the RMRs determined were applied to the semiquantitation of PSTs in contaminated mussels, showing good agreement with results from calibration with CRMs.
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Affiliation(s)
- Jiangbing Qiu
- College of Fisheries, Ocean University of China, Qingdao 266003, China;
| | - Elliott J. Wright
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (E.J.W.); (K.T.); (P.M.)
| | - Krista Thomas
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (E.J.W.); (K.T.); (P.M.)
| | - Aifeng Li
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China;
- Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao 266100, China
| | - Pearse McCarron
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (E.J.W.); (K.T.); (P.M.)
| | - Daniel G. Beach
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (E.J.W.); (K.T.); (P.M.)
- Correspondence: ; Tel.: +1-(902)-426-8274
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Biological Effects of the Azaspiracid-Producing Dinoflagellate Azadinium dexteroporum in Mytilus galloprovincialis from the Mediterranean Sea. Mar Drugs 2019; 17:md17100595. [PMID: 31652521 PMCID: PMC6835248 DOI: 10.3390/md17100595] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 12/11/2022] Open
Abstract
Azaspiracids (AZAs) are marine biotoxins including a variety of analogues. Recently, novel AZAs produced by the Mediterranean dinoflagellate Azadinium dexteroporum were discovered (AZA-54, AZA-55, 3-epi-AZA-7, AZA-56, AZA-57 and AZA-58) and their biological effects have not been investigated yet. This study aimed to identify the biological responses (biomarkers) induced in mussels Mytilus galloprovincialis after the bioaccumulation of AZAs from A. dexteroporum. Organisms were fed with A. dexteroporum for 21 days and subsequently subjected to a recovery period (normal diet) of 21 days. Exposed organisms accumulated AZA-54, 3-epi-AZA-7 and AZA-55, predominantly in the digestive gland. Mussels' haemocytes showed inhibition of phagocytosis activity, modulation of the composition of haemocytic subpopulation and damage to lysosomal membranes; the digestive tissue displayed thinned tubule walls, consumption of storage lipids and accumulation of lipofuscin. Slight genotoxic damage was also observed. No clear occurrence of oxidative stress and alteration of nervous activity was detected in AZA-accumulating mussels. Most of the altered parameters returned to control levels after the recovery phase. The toxic effects detected in M. galloprovincialis demonstrate a clear biological impact of the AZAs produced by A. dexteroporum, and could be used as early indicators of contamination associated with the ingestion of seafood.
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Effects of Temperature, Growth Media, and Photoperiod on Growth and Toxin Production of Azadinium spinosum. Mar Drugs 2019; 17:md17090489. [PMID: 31443393 PMCID: PMC6780083 DOI: 10.3390/md17090489] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/13/2019] [Accepted: 08/16/2019] [Indexed: 01/02/2023] Open
Abstract
Azaspiracids (AZAs) are microalgal toxins that can accumulate in shellfish and lead to human intoxications. To facilitate their study and subsequent biomonitoring, purification from microalgae rather than shellfish is preferable; however, challenges remain with respect to maximizing toxin yields. The impacts of temperature, growth media, and photoperiod on cell densities and toxin production in Azadinium spinosum were investigated. Final cell densities were similar at 10 and 18 °C, while toxin cell quotas were higher (~3.5-fold) at 10 °C. A comparison of culture media showed higher cell densities and AZA cell quotas (2.5-5-fold) in f10k compared to f/2 and L1 media. Photoperiod also showed differences, with lower cell densities in the 8:16 L:D treatment, while toxin cell quotas were similar for 12:12 and 8:16 L:D treatments but slightly lower for the 16:8 L:D treatment. AZA1, -2 and -33 were detected during the exponential phase, while some known and new AZAs were only detected once the stationary phase was reached. These compounds were additionally detected in field water samples during an AZA event.
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Samdal IA, Løvberg KE, Kristoffersen AB, Briggs LR, Kilcoyne J, Forsyth CJ, Miles CO. A Practical ELISA for Azaspiracids in Shellfish via Development of a New Plate-Coating Antigen. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:2369-2376. [PMID: 30763083 DOI: 10.1021/acs.jafc.8b05652] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Azaspiracids (AZAs) are a group of biotoxins that appear periodically in shellfish and can cause food poisoning in humans. Current methods for quantifying the regulated AZAs are restricted to LC-MS but are not well suited to detecting novel and unregulated AZAs. An ELISA method for total AZAs in shellfish was reported recently, but unfortunately, it used relatively large amounts of the AZA-1-containing plate-coating conjugate, consuming significant amounts of pure AZA-1 per assay. Therefore, a new plate-coater, OVA-cdiAZA1 was produced, resulting in an ELISA with a working range of 0.30-4.1 ng/mL and a limit of quantification of 37 μg/kg for AZA-1 in shellfish. This ELISA was nearly twice as sensitive as the previous ELISA while using 5-fold less plate-coater. The new ELISA displayed broad cross-reactivity toward AZAs, detecting all available quantitative AZA reference materials as well as the precursors to AZA-3 and AZA-6, and results from shellfish analyzed with the new ELISA showed excellent correlation ( R2 = 0.99) with total AZA-1-10 by LC-MS. The results suggest that the new ELISA is suitable for screening samples for total AZAs, even in cases where novel AZAs are present and regulated AZAs are absent, such as was reported recently from Puget Sound and the Bay of Naples.
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Affiliation(s)
- Ingunn A Samdal
- Norwegian Veterinary Institute , P.O. Box 750 Sentrum, N-0106 Oslo , Norway
| | - Kjersti E Løvberg
- Norwegian Veterinary Institute , P.O. Box 750 Sentrum, N-0106 Oslo , Norway
| | | | - Lyn R Briggs
- AgResearch Ltd., Ruakura Research Centre , Hamilton 3214 , New Zealand
| | - Jane Kilcoyne
- Marine Institute , Rinville, Oranmore, County Galway H91 R673 , Ireland
| | - Craig J Forsyth
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43220 , United States
| | - Christopher O Miles
- Norwegian Veterinary Institute , P.O. Box 750 Sentrum, N-0106 Oslo , Norway
- National Research Council Canada , 1411 Oxford St , Halifax , NS B3H 3Z1 , Canada
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13
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Abstract
Azaspiracid-34 (AZA34) is a recently described structurally unique member of the azaspiracid class of marine neurotoxins. Its novel structure, tentatively assigned on the basis of MS and 1H NMR spectroscopy, is accompanied by a 5.5-fold higher level of toxicity against Jurkat T lymphocytes than AZA1. To completely assign the structure of AZA34 and provide material for in-depth biological evaluation and detection, synthetic access to AZA34 was targeted. This began with the convergent and stereoselective assembly of the C1-C19 domain of AZA34 designed to dovetail with the recent total synthesis approach to AZA3.
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Affiliation(s)
- Antony A Okumu
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Craig J Forsyth
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
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14
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Kilcoyne J, McCarron P, Twiner MJ, Rise F, Hess P, Wilkins AL, Miles CO. Identification of 21,22-Dehydroazaspiracids in Mussels ( Mytilus edulis) and in Vitro Toxicity of Azaspiracid-26. JOURNAL OF NATURAL PRODUCTS 2018; 81:885-893. [PMID: 29488755 DOI: 10.1021/acs.jnatprod.7b00973] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Azaspiracids (AZAs) are marine biotoxins produced by the genera Azadinium and Amphidoma, pelagic marine dinoflagellates that may accumulate in shellfish resulting in human illness following consumption. The complexity of these toxins has been well documented, with more than 40 structural variants reported that are produced by dinoflagellates, result from metabolism in shellfish, or are extraction artifacts. Approximately 34 μg of a new AZA with MW 823 Da (AZA26 (3)) was isolated from blue mussels ( Mytilus edulis), and its structure determined by MS and NMR spectroscopy. AZA26, possibly a bioconversion product of AZA5, lacked the C-20-C-21 diol present in all AZAs reported thus far and had a 21,22-olefin and a keto group at C-23. Toxicological assessment of 3 using an in vitro model system based on Jurkat T lymphocyte cells showed the potency to be ∼30-fold lower than that of AZA1. The corresponding 21,22-dehydro-23-oxo-analogue of AZA10 (AZA28) and 21,22-dehydro analogues of AZA3, -4, -5, -6, -9, and -10 (AZA25, -48 (4), -60, -27, -49, and -61, respectively) were also identified by HRMS/MS, periodate cleavage reactivity, conversion from known analogues, and NMR (for 4 that was present in a partially purified sample of AZA7).
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Affiliation(s)
- Jane Kilcoyne
- Marine Institute , Rinville, Oranmore , Co. Galway H91 R673 , Ireland
| | - Pearse McCarron
- Measurement Science and Standards , National Research Council Canada , Halifax , NS B3H 3Z1 , Canada
| | - Michael J Twiner
- Department of Emergency Medicine, Detroit Receiving Hospital , Wayne State University , Detroit , Michigan 48202 , United States
| | - Frode Rise
- Department of Chemistry , University of Oslo , N-0315 Oslo , Norway
| | - Philipp Hess
- Ifremer, Laboratoire Phycotoxines , Rue de l'Ile d'Yeu , 44311 Nantes , France
| | - Alistair L Wilkins
- Norwegian Veterinary Institute , P.O. Box 750 Sentrum, 0106 Oslo , Norway
| | - Christopher O Miles
- Measurement Science and Standards , National Research Council Canada , Halifax , NS B3H 3Z1 , Canada
- Norwegian Veterinary Institute , P.O. Box 750 Sentrum, 0106 Oslo , Norway
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15
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Miles CO, Kilcoyne J, McCarron P, Giddings SD, Waaler T, Rundberget T, Samdal IA, Løvberg KE. Selective Extraction and Purification of Azaspiracids from Blue Mussels ( Mytilus edulis) Using Boric Acid Gel. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:2962-2969. [PMID: 29502403 DOI: 10.1021/acs.jafc.8b00346] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Azaspiracids belong to a family of more than 50 polyether toxins originating from marine dinoflagellates such as Azadinium spinosum. All of the azaspiracids reported thus far contain a 21,22-dihydroxy group. Boric acid gel can bind selectively to compounds containing vic-diols or α-hydroxycarboxylic acids via formation of reversible boronate complexes. Here we report use of the gel to selectively capture and release azaspiracids from extracts of blue mussels. Analysis of the extracts and fractions by liquid chromatography-tandem mass spectrometry (LC-MS) showed that this procedure resulted in an excellent cleanup of the azaspiracids in the extract. Analysis by enzyme-linked immunoasorbent assay (ELISA) and LC-MS indicated that most azaspiracid analogues were recovered in good yield by this procedure. The capacity of boric acid gel for azaspiracids was at least 50 μg/g, making this procedure suitable for use in the early stages of preparative purification of azaspiracids. In addition to its potential for concentration of dilute samples, the extensive cleanup provided by boric acid gel fractionation of azaspiracids in mussel samples almost eliminated matrix effects during subsequent LC-MS and could be expected to reduce matrix effects during ELISA analysis. The method may therefore prove useful for quantitative analysis of azaspiracids as part of monitoring programs. Although LC-MS data showed that okadaic acid analogues also bound to the gel, this was much less efficient than for azaspiracids under the conditions used. The boric acid gel methodology is potentially applicable to other important groups of natural toxins containing diols including ciguatoxins, palytoxins, pectenotoxins, tetrodotoxin, trichothecenes, and toxin glycosides.
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Affiliation(s)
- Christopher O Miles
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum , N-0106 Oslo , Norway
- Measurement Science and Standards , National Research Council , 1411 Oxford Street , Halifax , Nova Scotia B3H 3Z1 , Canada
| | - Jane Kilcoyne
- Marine Institute, Rinville, Oranmore, Co., Galway H91 R673 , Ireland
| | - Pearse McCarron
- Measurement Science and Standards , National Research Council , 1411 Oxford Street , Halifax , Nova Scotia B3H 3Z1 , Canada
| | - Sabrina D Giddings
- Measurement Science and Standards , National Research Council , 1411 Oxford Street , Halifax , Nova Scotia B3H 3Z1 , Canada
| | - Thor Waaler
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum , N-0106 Oslo , Norway
| | - Thomas Rundberget
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum , N-0106 Oslo , Norway
- Norwegian Institute for Water Research , N-0349 Oslo , Norway
| | - Ingunn A Samdal
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum , N-0106 Oslo , Norway
| | - Kjersti E Løvberg
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum , N-0106 Oslo , Norway
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16
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Toxic equivalency factors (TEFs) after acute oral exposure of azaspiracid 1, -2 and -3 in mice. Toxicol Lett 2017; 282:136-146. [PMID: 29107028 DOI: 10.1016/j.toxlet.2017.10.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 10/18/2017] [Accepted: 10/25/2017] [Indexed: 11/22/2022]
Abstract
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: 135-1100μg/kg; AZA2 and AZA3: 300-1100μg/kg) and sacrificed after 24h or 14days. TEFs derived from the median lethal doses (LD50) were 1.0, 0.7 and 0.5, respectively for AZA1, -2 and -3. In fact, after 24h from gavage administration, LD50s were 443μg/kg (AZA1; 95% CL: 350-561μg/kg), 626μg/kg (AZA2; 95% CL: 430-911μg/kg) and 875μg/kg (AZA3; 95% CL: 757-1010μg/kg). Mice dead more than 5h after the treatment or those sacrificed after 24h (doses: ≥175μg AZA1/kg, ≥500μg AZA2/kg and ≥600μg 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 (≥500mg/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 24h, 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 14days, AZA1 and AZA2 were still detectable in almost all the organs and intestinal content.
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17
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Zendong Z, Sibat M, Herrenknecht C, Hess P, McCarron P. Relative molar response of lipophilic marine algal toxins in liquid chromatography/electrospray ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:1453-1461. [PMID: 28582796 DOI: 10.1002/rcm.7918] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/01/2017] [Accepted: 06/01/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE 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 LC/MS with electrospray ionization (ESI). METHODS 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 acquisition modes (SIM, SRM, All-ion, target MS/MS) on low- and high-resolution mass spectrometers. RESULTS In general, RMRs were not significantly impacted by chromatographic conditions (isocratic vs gradient), with the exception of DTX1. MS acquisition modes had a more significant impact, with PnTX-G and SPX differing notably. For a given toxin group, response factors were generally in the range of 0.5 to 2. The cyclic imines were an exception. CONCLUSIONS Differences in RMRs between toxins of a same chemical base structure were not significant enough to indicate major issues for non-targeted semi-quantitative analysis, where there is limited or no availability of standards for many compounds, and where high degrees of accuracy are not required. Differences in RMRs should be considered when developing methods that use a standard of a single analogue to quantitate other toxins from the same group.
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Affiliation(s)
- Zita Zendong
- Ifremer, Laboratoire Phycotoxines, Nantes, France
| | | | | | - Philipp Hess
- Ifremer, Laboratoire Phycotoxines, Nantes, France
| | - Pearse McCarron
- Measurement Science and Standards, National Research Council Canada, Halifax, NS, Canada
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18
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McCarron P, Wright E, Emteborg H, Quilliam MA. A mussel tissue certified reference material for multiple phycotoxins. Part 4: certification. Anal Bioanal Chem 2016; 409:95-106. [PMID: 27830316 DOI: 10.1007/s00216-016-0004-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 10/04/2016] [Indexed: 11/26/2022]
Abstract
A freeze-dried mussel tissue (Mytilus edulis) reference material (CRM-FDMT1) was produced containing multiple groups of shellfish toxins. Homogeneity and stability testing showed the material to be fit for purpose. The next phase of work was to assign certified values and uncertainties to 10 analytes from six different toxin groups. Efforts involved optimizing extraction procedures for the various toxin groups and performing measurements using liquid chromatography-based analytical methods. A key aspect of the work was compensating for matrix effects associated with liquid chromatography-mass spectrometry through standard addition, dilution, or matrix-matched calibration. Certified mass fraction values are reported as mg/kg of CRM-FDMT1 powder as bottled for azaspiracid-1, -2, and -3 (4.10 ± 0.40; 1.13± 0.10; 0.96 ± 0.10, respectively), okadaic acid, dinophysistoxin-1 and -2 (1.59 ± 0.18; 0.68 ± 0.07; 3.57± 0.33, respectively), yessotoxin (2.49 ± 0.28), pectenotoxin-2 (0.66 ± 0.06), 13-desmethylspirolide-C (2.70 ± 0.26), and domoic acid (126 ± 10). Combined uncertainties for the certified values include contributions from homogeneity, stability, and characterization experiments. The commutability of CRM-FDMT1 was assessed by examining the extractability and matrix effects for the freeze-dried material in comparison with its equivalent wet tissue homogenate. CRM-FDMT1 is the first shellfish matrix CRM with certified values for yessotoxins, pectenotoxins or spirolides, and is the first CRM certified for multiple toxin groups. CRM-FDMT1 is a valuable tool for quality assurance of phycotoxin monitoring programs and for analytical method development and validation. Graphical Abstract CRM-FDMT1 is a multi-toxin mussel tissue certified reference material (CRM) to aid in development and validation of analytical methods for measuring the levels of algal toxins in seafood.
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Affiliation(s)
- Pearse McCarron
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada.
| | - Elliott Wright
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada
| | - Håkan Emteborg
- European Commission, Joint Research Centre, Directorate F - Health, Consumers, and Reference Materials, Retieseweg 111, 2440, Geel, Belgium
| | - Michael A Quilliam
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada
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Rossi R, Dell'Aversano C, Krock B, Ciminiello P, Percopo I, Tillmann U, Soprano V, Zingone A. Mediterranean Azadinium dexteroporum (Dinophyceae) produces six novel azaspiracids and azaspiracid-35: a structural study by a multi-platform mass spectrometry approach. Anal Bioanal Chem 2016; 409:1121-1134. [PMID: 27822651 DOI: 10.1007/s00216-016-0037-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/11/2016] [Accepted: 10/17/2016] [Indexed: 10/20/2022]
Abstract
Azadinium dexteroporum is the first species of the genus described from the Mediterranean Sea and it produces different azaspiracids (AZA). The aims of this work were to characterize the toxin profile of the species and gain structural information on azaspiracids produced by the A. dexteroporum strain SZN-B848 isolated from the Gulf of Naples. Liquid chromatography-mass spectrometry (LC-MS) analyses were carried out on three MS systems having different ion source geometries (ESI, TurboIonSpray®, ESI ION MAX) and different MS analyzers operating either at unit resolution or at high resolution, namely a hybrid triple quadrupole-linear ion trap (Q-Trap MS), a time of flight (TOF MS), and a hybrid linear ion trap Orbitrap XL Fourier transform mass spectrometer (LTQ Orbitrap XL FTMS). As a combined result of these different analyses, A. dexteroporum showed to produce AZA-35, previously reported from Azadinium spinosum, and six compounds that represent new additions to the AZA-group of toxins, including AZA-54 to AZA-58 and 3-epiAZA-7, a stereoisomer of the shellfish metabolite AZA-7. Based on the interpretation of fragmentation patterns, we propose that all these molecules, except AZA-55, have the same A to I ring system as AZA-1, with structural modifications all located in the carboxylic side chain. Considering that none of the azaspiracids produced by the Mediterranean strain of A. dexteroporum is currently regulated by European food safety authorities, monitoring programs of marine biotoxins in the Mediterranean area should take into account the occurrence of the new analogues to avoid an underestimation of the AZA-related risk for seafood consumers. Graphical Abstract A multi-platform MS approach reveals known and new azaspiracids in a Mediterranean strain of Azadinium dexteroporum.
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Affiliation(s)
- Rachele Rossi
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, 80055, Portici, Italy
| | - Carmela Dell'Aversano
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy.
| | - Bernd Krock
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Patrizia Ciminiello
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131, Napoli, Italy
| | - Isabella Percopo
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Urban Tillmann
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - Vittorio Soprano
- Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, 80055, Portici, Italy
| | - Adriana Zingone
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
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20
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Abstract
This review covers the literature published in 2014 for marine natural products (MNPs), with 1116 citations (753 for the period January to December 2014) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1378 in 456 papers for 2014), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.
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Affiliation(s)
- John W Blunt
- Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
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21
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Kilcoyne J, McCarron P, Hess P, Miles CO. Effects of Heating on Proportions of Azaspiracids 1-10 in Mussels (Mytilus edulis) and Identification of Carboxylated Precursors for Azaspiracids 5, 10, 13, and 15. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:10980-10987. [PMID: 26631586 DOI: 10.1021/acs.jafc.5b04609] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
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 after heating, leading to the identification of novel carboxylated AZA precursors in raw shellfish extracts, which were shown by deuterium labeling to be precursors for 5, 10, 13, and 15.
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Affiliation(s)
- Jane Kilcoyne
- Marine Institute , Rinville, Oranmore, Co. Galway, Ireland
| | - Pearse McCarron
- Measurement Science and Standards, National Research Council Canada , Halifax, Nova Scotia B3H 3Z1, Canada
| | - Philipp Hess
- Laboratoire Phycotoxines, Ifremer , Rue de l'Ile d'Yeu, 44311 Nantes, France
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22
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Krock B, Tillmann U, Potvin É, Jeong HJ, Drebing W, Kilcoyne J, Al-Jorani A, Twiner MJ, Göthel Q, Köck M. Structure Elucidation and in Vitro Toxicity of New Azaspiracids Isolated from the Marine Dinoflagellate Azadinium poporum. Mar Drugs 2015; 13:6687-702. [PMID: 26528990 PMCID: PMC4663548 DOI: 10.3390/md13116687] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 06/14/2015] [Accepted: 10/14/2015] [Indexed: 11/23/2022] Open
Abstract
Two strains of Azadinium poporum, one from the Korean West coast and the other from the North Sea, were mass cultured for isolation of new azaspiracids. Approximately 0.9 mg of pure AZA-36 (1) and 1.3 mg of pure AZA-37 (2) were isolated from the Korean (870 L) and North Sea (120 L) strains, respectively. The structures were determined to be 3-hydroxy-8-methyl-39-demethyl-azaspiracid-1 (1) and 3-hydroxy-7,8-dihydro-39-demethyl-azaspiracid-1 (2) by ¹H- and (13)C-NMR. Using the Jurkat T lymphocyte cell toxicity assay, (1) and (2) were found to be 6- and 3-fold less toxic than AZA-1, respectively.
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Affiliation(s)
- Bernd Krock
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, Bremerhaven 27570, Germany; E-Mails: (U.T.); (W.D.); (Q.G.)
| | - Urban Tillmann
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, Bremerhaven 27570, Germany; E-Mails: (U.T.); (W.D.); (Q.G.)
| | - Éric Potvin
- Division of Polar Ocean Environment, Korea Polar Research Institute, Incheon 406-840, Korea; E-Mail:
| | - Hae Jin Jeong
- School of Earth and Environmental Science, Seoul National University, Seoul 151-747, Korea; E-Mail:
| | - Wolfgang Drebing
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, Bremerhaven 27570, Germany; E-Mails: (U.T.); (W.D.); (Q.G.)
| | - Jane Kilcoyne
- Marine Institute, Rinville, Oranmore, Co. Galway, H91 R673, Ireland; E-Mail:
| | - Ahmed Al-Jorani
- Department of Natural Sciences, University of Michigan, Dearborn, MI 48202, USA; E-Mails: (A.A.-J.); (M.J.T.)
| | - Michael J. Twiner
- Department of Natural Sciences, University of Michigan, Dearborn, MI 48202, USA; E-Mails: (A.A.-J.); (M.J.T.)
| | - Qun Göthel
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, Bremerhaven 27570, Germany; E-Mails: (U.T.); (W.D.); (Q.G.)
| | - Matthias Köck
- Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, Bremerhaven 27570, Germany; E-Mails: (U.T.); (W.D.); (Q.G.)
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23
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Samdal IA, Løvberg KE, Briggs LR, Kilcoyne J, Xu J, Forsyth CJ, Miles CO. Development of an ELISA for the Detection of Azaspiracids. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:7855-7861. [PMID: 26245830 DOI: 10.1021/acs.jafc.5b02513] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Azaspiracids (AZAs) are a group of biotoxins that cause food poisoning in humans. These toxins are produced by small marine dinoflagellates such as Azadinium spinosum and accumulate in shellfish. Ovine polyclonal antibodies were produced and used to develop an ELISA for quantitating AZAs in shellfish, algal cells, and culture supernatants. Immunizing antigens were prepared from synthetic fragments of the constant region of AZAs, while plate coating antigen was prepared from AZA-1. The ELISA provides a sensitive and rapid analytical method for screening large numbers of samples. It has a working range of 0.45-8.6 ng/mL and a limit of quantitation for total AZAs in whole shellfish at 57 μg/kg, well below the maximum permitted level set by the European Commission. The ELISA has good cross-reactivity to AZA-1-10, -33, and -34 and 37-epi-AZA-1. Naturally contaminated Irish mussels gave similar results whether they were cooked or uncooked, indicating that the ELISA also detects 22-carboxy-AZA metabolites (e.g., AZA-17 and AZA-19). ELISA results showed excellent correlation with LC-MS/MS analysis, both for mussel extract spiked with AZA-1 and for naturally contaminated Irish mussels. The assay is therefore well suited to screening for AZAs in shellfish samples intended for human consumption, as well as for studies on AZA metabolism.
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Affiliation(s)
- Ingunn A Samdal
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106 Oslo, Norway
| | - Kjersti E Løvberg
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106 Oslo, Norway
| | - Lyn R Briggs
- AgResearch, Ruakura, East Street, Private Bag 3123, Hamilton, New Zealand
| | - Jane Kilcoyne
- Marine Institute , Rinville, Oranmore, County Galway, Ireland
| | - Jianyan Xu
- Department of Chemistry, University of Minnesota-Twin Cities , Minneapolis, Minnesota 55455, United States
| | - Craig J Forsyth
- Department of Chemistry and Biochemistry, The Ohio State University , Columbus, Ohio 43210, United States
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He JW, Bondy GS, Zhou T, Caldwell D, Boland GJ, Scott PM. Toxicology of 3-epi-deoxynivalenol, a deoxynivalenol-transformation product by Devosia mutans 17-2-E-8. Food Chem Toxicol 2015; 84:250-9. [PMID: 26363308 DOI: 10.1016/j.fct.2015.09.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 08/14/2015] [Accepted: 09/02/2015] [Indexed: 11/24/2022]
Abstract
Microbial detoxification of deoxynivalenol (DON) represents a new approach to treating DON-contaminated grains. A bacterium Devosia mutans 17-2-E-8 was capable of completely transforming DON into a major product 3-epi-DON and a minor product 3-keto-DON. Evaluation of toxicities of these DON-transformation products is an important part of hazard characterization prior to commercialization of the biotransformation application. Cytotoxicities of the products were demonstrated by two assays: a MTT bioassay assessing cell viability and a BrdU assay assessing DNA synthesis. Compared with DON, the IC50 values of 3-epi-DON and 3-keto-DON were respectively 357 and 3.03 times higher in the MTT bioassay, and were respectively 1181 and 4.54 times higher in the BrdU bioassay. Toxicological effects of 14-day oral exposure of the B6C3F1 mouse to DON and 3-epi-DON were also investigated. Overall, there were no differences between the control (free of toxin) and the 25 mg/kg bw/day or 100 mg/kg bw/day 3-epi-DON treatments in body and organ weights, hematology and organ histopathology. However, in mice exposed to DON (2 mg/kg bw/day), white blood cell numbers and serum immunoglobulin levels were altered relative to controls, and lesions were observed in adrenals, thymus, stomach, spleen and colon. Taken together, in vitro and in vivo studies indicate that 3-epi-DON is substantially less toxic than DON.
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Affiliation(s)
- Jian Wei He
- Guelph Food Research Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada; School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Genevieve S Bondy
- Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada.
| | - Ting Zhou
- Guelph Food Research Centre, Agriculture and Agri-Food Canada, Guelph, Ontario, Canada.
| | - Don Caldwell
- Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada
| | - Greg J Boland
- School of Environmental Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Peter M Scott
- Bureau of Chemical Safety, Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada
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He JW, Yang R, Zhou T, Boland GJ, Scott PM, Bondy GS. An epimer of deoxynivalenol: purification and structure identification of 3-epi-deoxynivalenol. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2015; 32:1523-30. [PMID: 26247304 DOI: 10.1080/19440049.2015.1072771] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In an investigation of deoxynivalenol (DON)-transformation products by Devosia mutans 17-2-E-8, the major product was identified as 3-epi-DON. This DON-transformation product was analysed by liquid chromatography and identified by congruent retention time and UV/Vis spectrum, as well as mass spectrometric data. Nuclear magnetic resonance (NMR) experiments including correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC) and nuclear overhauser effect (NOE) were conducted for structural characterisation of 3-epi-DON. High-speed counter-current chromatography (HSCCC) was applied to scale up the separation of 3-epi-DON from DON in a D. mutans 17-2-E-8 culture. From the culture where 100 mg DON was applied, 56 mg of 3-epi-DON (purity of 96.8%) was obtained from the HSCCC. The purified 3-epi-DON will be used for toxicological characterisation studies of this chemical.
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Affiliation(s)
- Jian Wei He
- a Guelph Food Research Centre , Agriculture and Agri-Food Canada , Guelph, ON , Canada
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26
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Kilcoyne J, Twiner MJ, McCarron P, Crain S, Giddings SD, Foley B, Rise F, Hess P, Wilkins AL, Miles CO. Structure Elucidation, Relative LC-MS Response and In Vitro Toxicity of Azaspiracids 7-10 Isolated from Mussels (Mytilus edulis). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:5083-5091. [PMID: 25909151 DOI: 10.1021/acs.jafc.5b01320] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
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 concentration-dependent 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.
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Affiliation(s)
- Jane Kilcoyne
- †Marine Institute, Rinville, Oranmore, County Galway, Ireland
- ‡School of Chemical and Pharmaceutical Sciences, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland
| | - Michael J Twiner
- §School of Medicine, Wayne State University, Detroit, Michigan 48202, United States
| | - Pearse McCarron
- ⊥Measurement Science and Standards, Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia B3H 3Z1, Canada
| | - Sheila Crain
- ⊥Measurement Science and Standards, Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia B3H 3Z1, Canada
| | - Sabrina D Giddings
- ⊥Measurement Science and Standards, Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia B3H 3Z1, Canada
| | - Barry Foley
- ‡School of Chemical and Pharmaceutical Sciences, Dublin Institute of Technology, Kevin Street, Dublin 8, Ireland
| | - Frode Rise
- ∥Department of Chemistry, University of Oslo, N-0315 Oslo, Norway
| | - Philipp Hess
- ▽Ifremer, Laboratoire Phycotoxines, Rue de l'Ile d'Yeu, 44311 Nantes, France
| | | | - Christopher O Miles
- ○Norwegian Veterinary Institute, P.O. Box 750 Sentrum, 0106 Oslo Norway
- #Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, N-0316 Oslo Norway
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Chevallier OP, Graham SF, Alonso E, Duffy C, Silke J, Campbell K, Botana LM, Elliott CT. New insights into the causes of human illness due to consumption of azaspiracid contaminated shellfish. Sci Rep 2015; 5:9818. [PMID: 25928256 PMCID: PMC4415421 DOI: 10.1038/srep09818] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 03/18/2015] [Indexed: 12/29/2022] Open
Abstract
Azaspiracid (AZA) poisoning was unknown until 1995 when shellfish harvested in Ireland caused illness manifesting by vomiting and diarrhoea. Further in vivo/vitro studies showed neurotoxicity linked with AZA exposure. However, the biological target of the toxin which will help explain such potent neurological activity is still unknown. A region of Irish coastline was selected and shellfish were sampled and tested for AZA using mass spectrometry. An outbreak was identified in 2010 and samples collected before and after the contamination episode were compared for their metabolite profile using high resolution mass spectrometry. Twenty eight ions were identified at higher concentration in the contaminated samples. Stringent bioinformatic analysis revealed putative identifications for seven compounds including, glutarylcarnitine, a glutaric acid metabolite. Glutaric acid, the parent compound linked with human neurological manifestations was subjected to toxicological investigations but was found to have no specific effect on the sodium channel (as was the case with AZA). However in combination, glutaric acid (1mM) and azaspiracid (50nM) inhibited the activity of the sodium channel by over 50%. Glutaric acid was subsequently detected in all shellfish employed in the study. For the first time a viable mechanism for how AZA manifests itself as a toxin is presented.
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Affiliation(s)
- O P Chevallier
- Advanced Asset Technology Centre, Institute for Global Food Security, Queen's University Belfast, Stranmillis Road, Belfast, BT9 5AG, UK
| | - S F Graham
- Beaumont Research Institute, 3811 W Thirteen Mile Road, Royal Oak, MI, 48073
| | - E Alonso
- Department of Pharmacology, Faculty of Veterinary, Campus Lugo, USC, 27002 Lugo, Spain
| | - C Duffy
- Marine Institute, Rinville, Oranmore, Co. Galway, Ireland
| | - J Silke
- Marine Institute, Rinville, Oranmore, Co. Galway, Ireland
| | - K Campbell
- Advanced Asset Technology Centre, Institute for Global Food Security, Queen's University Belfast, Stranmillis Road, Belfast, BT9 5AG, UK
| | - L M Botana
- Department of Pharmacology, Faculty of Veterinary, Campus Lugo, USC, 27002 Lugo, Spain
| | - C T Elliott
- Advanced Asset Technology Centre, Institute for Global Food Security, Queen's University Belfast, Stranmillis Road, Belfast, BT9 5AG, UK
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28
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Kilcoyne J, Nulty C, Jauffrais T, McCarron P, Herve F, Foley B, Rise F, Crain S, Wilkins AL, Twiner MJ, Hess P, Miles CO. Isolation, structure elucidation, relative LC-MS response, and in vitro toxicity of azaspiracids from the dinoflagellate Azadinium spinosum. JOURNAL OF NATURAL PRODUCTS 2014; 77:2465-2474. [PMID: 25356854 DOI: 10.1021/np500555k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We identified three new azaspiracids (AZAs) with molecular weights of 715, 815, and 829 (AZA33 (3), AZA34 (4), and AZA35, respectively) in mussels, seawater, and Azadinium spinosum culture. Approximately 700 μg of 3 and 250 μg of 4 were isolated from a bulk culture of A. spinosum, and their structures determined by MS and NMR spectroscopy. These compounds differ significantly at the carboxyl end of the molecule from known AZA analogues and therefore provide valuable information on structure-activity relationships. Initial toxicological assessment was performed using an in vitro model system based on Jurkat T lymphocyte cytotoxicity, and the potencies of 3 and 4 were found to be 0.22- and 5.5-fold that of AZA1 (1), respectively. Thus, major changes in the carboxyl end of 1 resulted in significant changes in toxicity. In mussel extracts, 3 was detected at low levels, whereas 4 and AZA35 were detected only at extremely low levels or not at all. The structures of 3 and 4 are consistent with AZAs being biosynthetically assembled from the amino end.
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Affiliation(s)
- Jane Kilcoyne
- Marine Institute , Rinville, Oranmore, Galway, Ireland
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29
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McCarron P, Giddings SD, Reeves KL, Hess P, Quilliam MA. A mussel (Mytilus edulis) tissue certified reference material for the marine biotoxins azaspiracids. Anal Bioanal Chem 2014; 407:2985-96. [PMID: 25335820 DOI: 10.1007/s00216-014-8250-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/02/2014] [Accepted: 10/07/2014] [Indexed: 11/28/2022]
Abstract
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. Quantitation methods based on standard addition and matrix-matched calibration were used to compensate for the matrix effects in LC-MS/MS. Other toxins present in this CRM at lower levels were also measured with information values reported for okadaic acid, dinophysistoxin-2, yessotoxin, and several spirolides.
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Affiliation(s)
- Pearse McCarron
- National Research Council of Canada, Measurement Science and Standards, Biotoxin Metrology, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada,
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