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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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3
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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: 2] [Impact Index Per Article: 2.0] [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: 4] [Impact Index Per Article: 4.0] [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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Xu T, Wang M, Liu X, Feng D, Zhu Y, Fan Z, Rao S, Lu J. A Scaffold-based Deep Generative Model Considering Molecular Stereochemical Information. Mol Inform 2022; 41:e2200088. [PMID: 36031563 DOI: 10.1002/minf.202200088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Designing molecules with specific scaffolds can facilitate the discovery and optimization of lead compounds. Some scaffold-based molecular generation models have been developed using deep-learning methods based on specific scaffolds, although incorporating scaffold generalization is expected to achieve scaffold hopping. Moreover, most of the existing models focus on the 2D shape of the scaffold and overlook the stereochemical properties of the compound, especially for natural products. In this study, we optimized the scaffold-based molecular generation model designed by Lim et al. (Chemical Science 2020, 11, 1153-1164). Real-time ultrafast shape recognition with pharmacophore constraints (USRCAT) was introduced into the model to search for molecules similar to the 3D conformation and pharmacophore of the input scaffold sourced from the training set; the searched molecules were then used as new scaffolds to execute scaffold hopping. The optimized model could generate new molecules with the same chirality as the input scaffold. Furthermore, the probability distribution of the molecular structure and various physicochemical properties were analyzed to evaluate the model's generation capability. We thus believe that the optimized model can provide a basis for medicinal chemists to explore a wider chemical space toward optimization of the lead compounds and to screen the virtual compound library.
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Affiliation(s)
- Tianxu Xu
- Department, Institution:Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, School of Pharmacy, Yantai University, No. 30, Qingquan Road, Laishan District, Yantai, 264005, China
| | - Minjun Wang
- Department, Institution:Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, School of Pharmacy, Yantai University, No. 30, Qingquan Road, Laishan District, Yantai, 264005, China
| | - Xiaoqian Liu
- Department, Institution:Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, School of Pharmacy, Yantai University, No. 30, Qingquan Road, Laishan District, Yantai, 264005, China
| | - Dawei Feng
- Department, Institution:Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, School of Pharmacy, Yantai University, No. 30, Qingquan Road, Laishan District, Yantai, 264005, China
| | - Yanjuan Zhu
- Department, Institution:Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, School of Pharmacy, Yantai University, No. 30, Qingquan Road, Laishan District, Yantai, 264005, China
| | - Zhe Fan
- Department, Institution:Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, School of Pharmacy, Yantai University, No. 30, Qingquan Road, Laishan District, Yantai, 264005, China
| | - Shurong Rao
- Department, Institution:Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, School of Pharmacy, Yantai University, No. 30, Qingquan Road, Laishan District, Yantai, 264005, China
| | - Jing Lu
- Department, Institution:Key Laboratory of Molecular Pharmacology and Drug Evaluation, Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, School of Pharmacy, Yantai University, No. 30, Qingquan Road, Laishan District, Yantai, 264005, China
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Samdal IA, Sandvik M, Vu J, Sukenthirarasa MS, Kanesamurthy S, Løvberg KLE, Kilcoyne J, Forsyth CJ, Wright EJ, Miles CO. Preparation and characterization of an immunoaffinity column for the selective extraction of azaspiracids. J Chromatogr B Analyt Technol Biomed Life Sci 2022; 1207:123360. [PMID: 35839625 DOI: 10.1016/j.jchromb.2022.123360] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 11/19/2022]
Abstract
The presence of azaspiracids (AZAs) in shellfish may cause food poisoning in humans. AZAs can accumulate in shellfish filtering seawater that contains marine dinoflagellates such as Azadinium and Amphidoma spp. More than 60 AZA analogues have been identified, of which AZA1, AZA2 and AZA3 are regulated in Europe. Shellfish matrices may complicate quantitation by ELISA and LC-MS methods. Polyclonal antibodies have been developed that bind specifically to the C-26-C-40 domain of the AZA structure and could potentially be used for selectively extracting compounds containing this substructure. This includes almost all known analogues of AZAs, including AZA1, AZA2 and AZA3. Here we report preparation of immunoaffinity chromatography (IAC) columns for clean-up and concentration of AZAs. The IAC columns were prepared by coupling polyclonal anti-AZA IgG to CNBr-activated sepharose. The columns were evaluated using shellfish extracts, and the resulting fractions were analyzed by ELISA and LC-MS. The columns selectively bound over 300 ng AZAs per mL of gel without significant leakage, and did not retain the okadaic acid, cyclic imine, pectenotoxin and yessotoxin analogues that were present in the applied samples. Furthermore, 90-92% of the AZAs were recovered by elution with 90% MeOH, and the columns could be re-used without significant loss of performance.
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Affiliation(s)
- Ingunn A Samdal
- Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway.
| | - Morten Sandvik
- Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway
| | - Jennie Vu
- Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway; Oslo Metropolitan University, P.O. Box 4, St. Olavs plass, N-0130 Oslo, Norway
| | - Merii S Sukenthirarasa
- Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway; Oslo Metropolitan University, P.O. Box 4, St. Olavs plass, N-0130 Oslo, Norway
| | - Sinthuja Kanesamurthy
- Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway; Oslo Metropolitan University, P.O. Box 4, St. Olavs plass, N-0130 Oslo, Norway
| | | | - Jane Kilcoyne
- Marine Institute, Rinville, Oranmore H91 R673, County Galway, Ireland
| | - Craig J Forsyth
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43220, United States
| | - Elliott J Wright
- Biotoxin Metrology, National Research Council of Canada, 1411 Oxford Street, Halifax, Nova Scotia B3H 3Z1, Canada
| | - Christopher O Miles
- Norwegian Veterinary Institute, P.O. Box 64, 1431 Ås, Norway; Biotoxin Metrology, National Research Council of Canada, 1411 Oxford Street, Halifax, Nova Scotia B3H 3Z1, Canada
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Shen SM, Appendino G, Guo YW. Pitfalls in the structural elucidation of small molecules. A critical analysis of a decade of structural misassignments of marine natural products. Nat Prod Rep 2022; 39:1803-1832. [PMID: 35770685 DOI: 10.1039/d2np00023g] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Covering: July 2010 to August 2021This article summarizes more than 200 cases of misassigned marine natural products reported between July 2010 and August 2021, sorting out errors according to the structural elements. Based on a comparative analysis of the original and the revised structures, major pitfalls still plaguing the structural elucidation of small molecules were identified, emphasizing the role of total synthesis, crystallography, as well as chemical- and biosynthetic logic to complement spectroscopic data. Distinct "trends" in natural product misassignment are evident between compounds of marine and plant origin, with an overall much lower incidence of "impossible" structures within misassigned marine natural products.
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Affiliation(s)
- Shou-Mao Shen
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China. .,School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Giovanni Appendino
- Dipartimento di Scienze del Farmaco, Universitá degli Studi del Piemonte Orientale, Largo Donegani 2, 28100 Novara, Italy
| | - Yue-Wei Guo
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China. .,Drug Discovery Shandong Laboratory, Bohai Rim Advanced Research Institute for Drug Discovery, Yantai, Shandong 264117, China
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Sandvik M, Miles CO, Løvberg KLE, Kryuchkov F, Wright EJ, Mudge EM, Kilcoyne J, Samdal IA. In Vitro Metabolism of Azaspiracids 1-3 with a Hepatopancreatic Fraction from Blue Mussels ( Mytilus edulis). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:11322-11335. [PMID: 34533950 DOI: 10.1021/acs.jafc.1c03831] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Azaspiracids (AZAs) are a group of biotoxins produced by the marine dinoflagellates Azadinium and Amphidoma spp. that can accumulate in shellfish and cause food poisoning in humans. Of the 60 AZAs identified, levels of AZA1, AZA2, and AZA3 are regulated in shellfish as a food safety measure based on occurrence and toxicity. Information about the metabolism of AZAs in shellfish is limited. Therefore, a fraction of blue mussel hepatopancreas was made to study the metabolism of AZA1-3 in vitro. A range of AZA metabolites were detected by liquid chromatography-high-resolution tandem mass spectrometry analysis, most notably the novel 22α-hydroxymethylAZAs AZA65 and AZA66, which were also detected in naturally contaminated mussels. These appear to be the first intermediates in the metabolic conversion of AZA1 and AZA2 to their corresponding 22α-carboxyAZAs (AZA17 and AZA19). α-Hydroxylation at C-23 was also a prominent metabolic pathway, producing AZA8, AZA12, and AZA5 as major metabolites of AZA1-3, respectively, and AZA67 and AZA68 as minor metabolites via double-hydroxylation of AZA1 and AZA2, but only low levels of 3β-hydroxylation were observed in this study. In vitro generation of algal toxin metabolites, such as AZA3, AZA5, AZA6, AZA8, AZA12, AZA17, AZA19, AZA65, and AZA66 that would otherwise have to be laboriously purified from shellfish, has the potential to be used for the production of standards for analytical and toxicological studies.
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Affiliation(s)
- Morten Sandvik
- Norwegian Veterinary Institute, P.O. Box 64, N-1431 Ås, Norway
| | - Christopher O Miles
- Norwegian Veterinary Institute, P.O. Box 64, N-1431 Ås, Norway
- Biotoxin Metrology, National Research Council Canada, Halifax, NS B3H 3Z1, Canada
| | | | - Fedor Kryuchkov
- Norwegian Veterinary Institute, P.O. Box 64, N-1431 Ås, Norway
| | - Elliott J Wright
- Biotoxin Metrology, National Research Council Canada, Halifax, NS B3H 3Z1, Canada
| | - Elizabeth M Mudge
- Biotoxin Metrology, National Research Council Canada, Halifax, NS B3H 3Z1, Canada
| | - Jane Kilcoyne
- Marine Institute, Rinville, Oranmore, County Galway H91 R673, Ireland
| | - Ingunn A Samdal
- Norwegian Veterinary Institute, P.O. Box 64, N-1431 Ås, Norway
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Abstract
This review covers the literature published between January and December in 2018 for marine natural products (MNPs), with 717 citations (706 for the period January to December 2018) 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 (1554 in 469 papers for 2018), together with the relevant biological activities, source organisms and country of origin. Reviews, biosynthetic studies, first syntheses, and syntheses that led to the revision of structures or stereochemistries, have been included. The proportion of MNPs assigned absolute configuration over the last decade is also surveyed.
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Affiliation(s)
- Anthony R Carroll
- School of Environment and Science, Griffith University, Gold Coast, Australia. and Griffith Institute for Drug Discovery, Griffith University, Brisbane, Australia
| | - Brent R Copp
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | - Rohan A Davis
- Griffith Institute for Drug Discovery, Griffith University, Brisbane, Australia and School of Environment and Science, Griffith University, Brisbane, Australia
| | - Robert A Keyzers
- Centre for Biodiscovery, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Michèle R Prinsep
- Chemistry, School of Science, University of Waikato, Hamilton, New Zealand
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Lam NYS, Paterson I. Stereocontrolled Synthesis as an Enabling Tool for the Configurational Assignment of Marine Polyketide Natural Products. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901243] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Nelson Y. S. Lam
- University Chemical Laboratory; Lensfield Road CB2 1EW Cambridge United Kingdom
| | - Ian Paterson
- University Chemical Laboratory; Lensfield Road CB2 1EW Cambridge United Kingdom
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Nicolaou KC, Rigol S, Yu R. Total Synthesis Endeavors and Their Contributions to Science and Society:A Personal Account. CCS CHEMISTRY 2019. [DOI: 10.31635/ccschem.019.20190006] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The advent of organic synthesis in the 19th century, serendipitous as it was, set in motion a revolution in science that continues to evolve into increasing levels of sophistication and to expand into new domains of science and technology for the benefits of science and society. Its evolution was always driven by the challenges posed by natural products, whose structures were becoming increasingly complex and diverse. In response to these challenges, synthetic organic chemists were prompted to sharpen their art to reach their target molecules, whose structures were often confirmed only after their synthesis in the laboratory through the art and science of total synthesis. The latter became the “locomotive” and the “flagship” of organic synthesis, for through this practice novel synthetic methods were discovered and invented, and also tested for their generality, applicability, and scope with regard to molecular complexity and diversity. The purpose of total synthesis has also evolved over the years to include aspects beyond the synthesis of the molecule and confirmation of its structure. In this article, we briefly review the evolution of total synthesis in terms of its power and reach and demonstrate its current state of the art that combines fundamentals with translational aspects through examples from our laboratories. The highlighted examples reflect the newly emerged paradigm of the discipline that includes—in addition to the total synthesis of the target molecule—structural elucidations, method discovery and development, design, synthesis, and biological evaluation of analogues for biology and medicine, and training of young students, preparing them for academic and industrial careers in the various disciplines that require knowledge and skills to practice the central science of chemical synthesis. Such disciplines include chemical biology, drug discovery and development, materials science and nanotechnology, and other endeavors whose fundamentals depend and rely on the structure of the molecule and its synthesis.
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Affiliation(s)
- K. C. Nicolaou
- Department of Chemistry, BioScience Research Collaborative, Rice University, 6100 Main Street, Houston,TX 77005 (United States of America)
| | - Stephan Rigol
- Department of Chemistry, BioScience Research Collaborative, Rice University, 6100 Main Street, Houston,TX 77005 (United States of America)
| | - Ruocheng Yu
- Department of Chemistry, BioScience Research Collaborative, Rice University, 6100 Main Street, Houston,TX 77005 (United States of America)
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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: 9] [Impact Index Per Article: 1.8] [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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Campano TE, Iriarte I, Olaizola O, Etxabe J, Mielgo A, Ganboa I, Odriozola JM, García JM, Oiarbide M, Palomo C. Enantioselective Addition of Alkynyl Ketones to Nitroolefins Assisted by Brønsted Base/H‐Bonding Catalysis. Chemistry 2019; 25:4390-4397. [DOI: 10.1002/chem.201805542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Teresa E. Campano
- Departamento de Química Orgánica IUniversidad del País Vasco UPV/EHU Manuel Lardizabal 3 20018 San Sebastián Spain
| | - Igor Iriarte
- Departamento de Química Orgánica IUniversidad del País Vasco UPV/EHU Manuel Lardizabal 3 20018 San Sebastián Spain
| | - Olatz Olaizola
- Departamento de Química Orgánica IUniversidad del País Vasco UPV/EHU Manuel Lardizabal 3 20018 San Sebastián Spain
| | - Julen Etxabe
- Departamento de Química Orgánica IUniversidad del País Vasco UPV/EHU Manuel Lardizabal 3 20018 San Sebastián Spain
| | - Antonia Mielgo
- Departamento de Química Orgánica IUniversidad del País Vasco UPV/EHU Manuel Lardizabal 3 20018 San Sebastián Spain
| | - Iñaki Ganboa
- Departamento de Química Orgánica IUniversidad del País Vasco UPV/EHU Manuel Lardizabal 3 20018 San Sebastián Spain
| | - José M. Odriozola
- Departamento de Química AplicadaInstitute for Advanced Materials (INAMAT)Universidad Pública de Navarra 31006 Pamplona Spain
| | - Jesús M. García
- Departamento de Química AplicadaInstitute for Advanced Materials (INAMAT)Universidad Pública de Navarra 31006 Pamplona Spain
| | - Mikel Oiarbide
- Departamento de Química Orgánica IUniversidad del País Vasco UPV/EHU Manuel Lardizabal 3 20018 San Sebastián Spain
| | - Claudio Palomo
- Departamento de Química Orgánica IUniversidad del País Vasco UPV/EHU Manuel Lardizabal 3 20018 San Sebastián Spain
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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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15
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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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16
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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: 12] [Impact Index Per Article: 2.0] [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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