1
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Chintalapudi V, Wilson C, Clark JS. Synthesis of the I-K Fused Polyether Array of CTX3C and Related Ciguatoxins by Use of a Gold-Catalyzed Cyclization Reaction. Org Lett 2024; 26:775-780. [PMID: 38238251 PMCID: PMC10845158 DOI: 10.1021/acs.orglett.3c03782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 01/04/2024] [Accepted: 01/15/2024] [Indexed: 02/03/2024]
Abstract
The I-K fragment (C31-C49) of the ciguatoxin CTX3C has been synthesized from a simple chiral pool derived tetrahydropyranyl alcohol. An efficient gold-catalyzed cyclization reaction of a γ'-hydroxy ynone has been used to accomplish efficient closure of ring K under mild conditions. The resulting vinylogous ester has been elaborated to give a complete tricyclic fragment bearing the dimethyl-substituted side chain required for assembly of the LM spirocyclic acetal portion of the target.
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Affiliation(s)
| | - Claire Wilson
- School of Chemistry, Joseph
Black Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ, U.K.
| | - J. Stephen Clark
- School of Chemistry, Joseph
Black Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ, U.K.
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2
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Triantafyllakis M, Alexander S, Woolford S, Wilson C, Clark JS. Synthesis of the A-F Fragment of the Pacific Ciguatoxin CTX3C by Iterative Ring-Closing Metathesis and Tsuji-Trost Allylation. Chemistry 2023; 29:e202303121. [PMID: 37830907 PMCID: PMC10946863 DOI: 10.1002/chem.202303121] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/14/2023]
Abstract
The fully functionalized A-F fragment of the Pacific ciguatoxin CTX3C has been synthesized from a derivative of D-glucal, which serves as the B-ring. Rings A and C were introduced to either side of ring B by ring-closing diene and enyne metathesis (RCM). The seven-membered D-ring and eight-membered E-ring were assembled by iterative use of a six-step reaction sequence in which RCM was used for ring construction and Tsuji-Trost allylation was employed for subsequent stereoselective functionalization. The nine-membered F-ring was formed by use of an RCM reaction and bears the functionality required for attachment of the I-M fragment and subsequent closure of rings G and H.
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Affiliation(s)
- Myron Triantafyllakis
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
| | - Sam Alexander
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
| | - Sophie Woolford
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
| | - Claire Wilson
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
| | - J. Stephen Clark
- School of ChemistryJoseph Black BuildingUniversity of GlasgowUniversity AvenueGlasgowG12 8QQUK
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3
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Hamada S, Sumida M, Yamazaki R, Kobayashi Y, Furuta T. Oxidative Deprotection of Benzyl Protecting Groups for Alcohols by an Electronically Tuned Nitroxyl-Radical Catalyst. J Org Chem 2023; 88:12464-12473. [PMID: 37586039 DOI: 10.1021/acs.joc.3c01217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
The oxidative deprotection of benzyl (Bn) groups using nitroxyl-radical catalyst 1 and co-oxidant phenyl iodonium bis(trifluoroacetate) (PIFA) is reported. This catalyst is highly active for the oxidation of benzylic ethers because of the electronic tuning on account of the electron-withdrawing ester groups next to the catalytically active center. This catalytic system promotes deprotections at ambient temperature and has a broad substrate scope, including substrates possessing hydrogenation-sensitive functional groups, while the deprotection hardly proceeds when using well-known nitroxyl-radical catalysts such as 2,2,6,6-tetramethylpiperidine N-oxyl (TEMPO). The 1/PIFA system also promotes the deprotection of several benzylic protecting groups, including 2-naphthylmethyl (NAP) and 4-methylbenzyl (MBn) groups. Catalyst 1 was also effective for the direct synthesis of ketones and aldehydes from Bn ethers via deprotected alcohols using an excess of the co-oxidant PIFA.
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Affiliation(s)
- Shohei Hamada
- Laboratory of Pharmaceutical Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan
| | - Maiko Sumida
- Laboratory of Pharmaceutical Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan
| | - Rikako Yamazaki
- Laboratory of Pharmaceutical Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan
| | - Yusuke Kobayashi
- Laboratory of Pharmaceutical Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan
| | - Takumi Furuta
- Laboratory of Pharmaceutical Chemistry, Kyoto Pharmaceutical University, Yamashina-ku, Kyoto 607-8414, Japan
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4
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Ali R, Ahmed W, Jayant V, alvi S, Ahmed N, Ahmed A. Metathesis reactions in total‐ and natural product fragments syntheses. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202100753] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Rashid Ali
- Jamia Millia Islamia New Delhi India 110025 Department of Chemistry Jamia Nagar,New Delhi india110025 110025 New Delhi INDIA
| | - Waqar Ahmed
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - Vikrant Jayant
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - shakeel alvi
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - Nadeem Ahmed
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
| | - Azeem Ahmed
- Jamia Millia Islamia Central University: Jamia Millia Islamia Chemistry INDIA
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5
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Gwinn JK, Uhlig S, Ivanova L, Fæste CK, Kryuchkov F, Robertson A. In Vitro Glucuronidation of Caribbean Ciguatoxins in Fish: First Report of Conjugative Ciguatoxin Metabolites. Chem Res Toxicol 2021; 34:1910-1925. [PMID: 34319092 PMCID: PMC9215509 DOI: 10.1021/acs.chemrestox.1c00181] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ciguatoxins (CTX) are potent marine neurotoxins, which can bioaccumulate in seafood, causing a severe and prevalent human illness known as ciguatera poisoning (CP). Despite the worldwide impact of ciguatera, effective disease management is hindered by a lack of knowledge regarding the movement and biotransformation of CTX congeners in marine food webs, particularly in the Caribbean and Western Atlantic. In this study we investigated the hepatic biotransformation of C-CTX across several fish and mammalian species through a series of in vitro metabolism assays focused on phase I (CYP P450; functionalization) and phase II (UGT; conjugation) reactions. Using liquid chromatography high-resolution mass spectrometry to explore potential C-CTX metabolites, we observed two glucuronide products of C-CTX-1/-2 and provided additional evidence from high-resolution tandem mass spectrometry to support their identification. Chemical reduction experiments confirmed that the metabolites were comprised of four distinct glucuronide products with the sugar attached at two separate sites on C-CTX-1/-2 and excluded the C-56 hydroxyl group as the conjugation site. Glucuronidation is a novel biotransformation pathway not yet reported for CTX or other related polyether phycotoxins, yet its occurrence across all fish species tested suggests that it could be a prevalent and important detoxification mechanism in marine organisms. The absence of glucuronidation observed in this study for both rat and human microsomes suggests that alternate biotransformation pathways may be dominant in higher vertebrates.
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Affiliation(s)
- Jessica Kay Gwinn
- School of Marine and Environmental Sciences, University of South Alabama, Mobile, Alabama 36688, United States
- Dauphin Island Sea Lab, Dauphin Island, Alabama 36528, United States
| | - Silvio Uhlig
- Toxinology Research Group, Norwegian Veterinary Institute, Ås NO-1431, Norway
| | - Lada Ivanova
- Toxinology Research Group, Norwegian Veterinary Institute, Ås NO-1431, Norway
| | | | - Fedor Kryuchkov
- Toxinology Research Group, Norwegian Veterinary Institute, Ås NO-1431, Norway
| | - Alison Robertson
- School of Marine and Environmental Sciences, University of South Alabama, Mobile, Alabama 36688, United States
- Dauphin Island Sea Lab, Dauphin Island, Alabama 36528, United States
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6
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Sasaki M, Iwasaki K, Arai K. Synthesis and Structural Implication of the JKLMN-Ring Fragment of Caribbean Ciguatoxin C-CTX-1. J Org Chem 2021; 86:4580-4597. [PMID: 33667088 DOI: 10.1021/acs.joc.0c03031] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Synthesis of the JKLMN-ring fragment of Caribbean ciguatoxin C-CTX-1, the causative toxin of ciguatera fish poisoning in the Caribbean Sea and the Northeast Atlantic areas, is described in detail. Key to the synthesis are a [2,3]-sigmatropic rearrangement to construct a seven-membered α-hydroxy exo-enol ether, stereoselective construction of an angular tetrasubstituted stereogenic center on the seven-membered M-ring by a hydrogen atom transfer-based reductive olefin coupling, Suzuki-Miyaura coupling of the KLMN-ring enol phosphate with a highly congested M-ring, and silica gel-mediated epoxide ring opening to form the J-ring. Comparison of the nuclear magnetic resonance spectroscopic data for the synthesized fragment with those for the natural product provided support for the formerly assigned structure of the N-ring in the right-hand terminal of C-CTX-1.
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Affiliation(s)
- Makoto Sasaki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Japan
| | - Kotaro Iwasaki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Japan
| | - Keisuke Arai
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Japan
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7
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Loeffler CR, Tartaglione L, Friedemann M, Spielmeyer A, Kappenstein O, Bodi D. Ciguatera Mini Review: 21st Century Environmental Challenges and the Interdisciplinary Research Efforts Rising to Meet Them. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:3027. [PMID: 33804281 PMCID: PMC7999458 DOI: 10.3390/ijerph18063027] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/12/2021] [Accepted: 03/12/2021] [Indexed: 12/19/2022]
Abstract
Globally, the livelihoods of over a billion people are affected by changes to marine ecosystems, both structurally and systematically. Resources and ecosystem services, provided by the marine environment, contribute nutrition, income, and health benefits for communities. One threat to these securities is ciguatera poisoning; worldwide, the most commonly reported non-bacterial seafood-related illness. Ciguatera is caused by the consumption of (primarily) finfish contaminated with ciguatoxins, potent neurotoxins produced by benthic single-cell microalgae. When consumed, ciguatoxins are biotransformed and can bioaccumulate throughout the food-web via complex pathways. Ciguatera-derived food insecurity is particularly extreme for small island-nations, where fear of intoxication can lead to fishing restrictions by region, species, or size. Exacerbating these complexities are anthropogenic or natural changes occurring in global marine habitats, e.g., climate change, greenhouse-gas induced physical oceanic changes, overfishing, invasive species, and even the international seafood trade. Here we provide an overview of the challenges and opportunities of the 21st century regarding the many facets of ciguatera, including the complex nature of this illness, the biological/environmental factors affecting the causative organisms, their toxins, vectors, detection methods, human-health oriented responses, and ultimately an outlook towards the future. Ciguatera research efforts face many social and environmental challenges this century. However, several future-oriented goals are within reach, including digital solutions for seafood supply chains, identifying novel compounds and methods with the potential for advanced diagnostics, treatments, and prediction capabilities. The advances described herein provide confidence that the tools are now available to answer many of the remaining questions surrounding ciguatera and therefore protection measures can become more accurate and routine.
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Affiliation(s)
- Christopher R. Loeffler
- National Reference Laboratory of Marine Biotoxins, Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (A.S.); (O.K.); (D.B.)
- Department of Pharmacy, School of Medicine and Surgery, University of Napoli Federico II, Via D. Montesano 49, 80131 Napoli, Italy;
| | - Luciana Tartaglione
- Department of Pharmacy, School of Medicine and Surgery, University of Napoli Federico II, Via D. Montesano 49, 80131 Napoli, Italy;
- CoNISMa—National Inter-University Consortium for Marine Sciences, Piazzale Flaminio 9, 00196 Rome, Italy
| | - Miriam Friedemann
- Department Exposure, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany;
| | - Astrid Spielmeyer
- National Reference Laboratory of Marine Biotoxins, Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (A.S.); (O.K.); (D.B.)
| | - Oliver Kappenstein
- National Reference Laboratory of Marine Biotoxins, Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (A.S.); (O.K.); (D.B.)
| | - Dorina Bodi
- National Reference Laboratory of Marine Biotoxins, Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (A.S.); (O.K.); (D.B.)
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8
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Stereoselective Synthesis of the I-L Fragment of the Pacific Ciguatoxins. Toxins (Basel) 2020; 12:toxins12120740. [PMID: 33255410 PMCID: PMC7760828 DOI: 10.3390/toxins12120740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/20/2020] [Accepted: 11/20/2020] [Indexed: 11/17/2022] Open
Abstract
The I-L ring system found in all the Pacific ciguatoxins has been prepared from a tricyclic precursor in a highly stereoselective manner. Subtle differences in the reactivity of the enones present in the seven- and eight-membered rings of the tricyclic ether starting material have been exploited to allow selective protection of the enone in the eight-membered ring. Subsequent distereoselective allylation of the seven-membered ring has been accomplished by a palladium-mediated Tsuji-Trost reaction. The K-ring methyl and hydroxyl groups have been installed in a highly stereoselective manner by sequential conjugate reduction and enolate oxidation reactions. Ring L has been constructed by a use of a novel relay ring-closing metathesis reaction to complete the tetracyclic framework, which possesses the functionality necessary for elaboration of rings I and L and the introduction of ring M.
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9
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Popadynec M, Gibbard H, Clark JS. Bidirectional Synthesis of the IJK Fragment of Ciguatoxin CTX3C by Sequential Double Ring-Closing Metathesis and Tsuji-Trost Allylation. Org Lett 2020; 22:3734-3738. [PMID: 32306737 PMCID: PMC7304930 DOI: 10.1021/acs.orglett.0c01238] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
![]()
A novel four-step bidirectional strategy
has been used to synthesize
the IJK fragment of the marine polyether natural product CTX3C from
a simple monocyclic precursor in a concise and efficient manner. The
four-step bidirectional sequence involves ring-closing metathesis,
alcohol oxidation, enol carbonate formation, and palladium-mediated
Tsuji–Trost allylation.
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Affiliation(s)
- Michael Popadynec
- School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ, United Kingdom
| | - Helen Gibbard
- School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ, United Kingdom
| | - J Stephen Clark
- School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ, United Kingdom
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10
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Grygorenko OO, Volochnyuk DM, Ryabukhin SV, Judd DB. The Symbiotic Relationship Between Drug Discovery and Organic Chemistry. Chemistry 2019; 26:1196-1237. [PMID: 31429510 DOI: 10.1002/chem.201903232] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/19/2019] [Indexed: 12/20/2022]
Abstract
All pharmaceutical products contain organic molecules; the source may be a natural product or a fully synthetic molecule, or a combination of both. Thus, it follows that organic chemistry underpins both existing and upcoming pharmaceutical products. The reverse relationship has also affected organic synthesis, changing its landscape towards increasingly complex targets. This Review article sets out to give a concise appraisal of this symbiotic relationship between organic chemistry and drug discovery, along with a discussion of the design concepts and highlighting key milestones along the journey. In particular, criteria for a high-quality compound library design enabling efficient virtual navigation of chemical space, as well as rise and fall of concepts for its synthetic exploration (such as combinatorial chemistry; diversity-, biology-, lead-, or fragment-oriented syntheses; and DNA-encoded libraries) are critically surveyed.
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Affiliation(s)
- Oleksandr O Grygorenko
- Enamine Ltd., Chervonotkatska Street 78, Kiev, 02094, Ukraine.,Taras Shevchenko National University of Kiev, Volodymyrska Street 60, Kiev, 01601, Ukraine
| | - Dmitriy M Volochnyuk
- Enamine Ltd., Chervonotkatska Street 78, Kiev, 02094, Ukraine.,Taras Shevchenko National University of Kiev, Volodymyrska Street 60, Kiev, 01601, Ukraine.,Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Murmanska Street 5, Kiev, 02660, Ukraine
| | - Sergey V Ryabukhin
- Enamine Ltd., Chervonotkatska Street 78, Kiev, 02094, Ukraine.,Taras Shevchenko National University of Kiev, Volodymyrska Street 60, Kiev, 01601, Ukraine
| | - Duncan B Judd
- Awridian Ltd., Stevenage Bioscience Catalyst, Gunnelswood Road, Stevenage, Herts, SG1 2FX, UK
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11
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Tsumuraya T, Hirama M. Rationally Designed Synthetic Haptens to Generate Anti-Ciguatoxin Monoclonal Antibodies, and Development of a Practical Sandwich ELISA to Detect Ciguatoxins. Toxins (Basel) 2019; 11:E533. [PMID: 31540301 PMCID: PMC6784113 DOI: 10.3390/toxins11090533] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/02/2019] [Accepted: 09/06/2019] [Indexed: 12/02/2022] Open
Abstract
"Ciguatera" fish poisoning (CFP) is one of the well-known food poisoning caused by the ingestion of fish that have accumulated trace amounts of ciguatoxins (CTXs). CFP affects more than 50,000 individuals annually. The difficulty in preventing CFP comes from the lack of reliable methods for analysis of CTXs in contaminated fish, together with the normal appearance, taste, and smell of CTX-contaminated fish. Thus, a sensitive, accurate, routine, and portable analytical method to detect CTXs is urgently required. Monoclonal antibodies (mAbs) specific against either wing of major CTX congeners (CTX1B, 54-deoxyCTX1B, CTX3C, and 51-hydroxyCTX3C) were generated by immunizing mice with rationally designed synthetic haptens-KLH conjugates instead of the CTXs. Haptenic groups with a surface area greater than 400 Å2 are required to produce mAbs that can strongly bind to CTXs. Furthermore, a highly sensitive fluorescence-based sandwich enzyme-linked immunosorbent assay (ELISA) was developed. This protocol can detect and quantify four major CTX congeners (CTX1B, 54-deoxyCTX1B, CTX3C, and 51-hydroxyCTX3C) with a limit of detection (LOD) of less than 1 pg/mL. The LOD determined for this sandwich ELISA is sufficient to detect CTX1B-contaminated fish at the FDA guidance level of 0.01 ppb.
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Affiliation(s)
- Takeshi Tsumuraya
- Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-2, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan.
| | - Masahiro Hirama
- Department of Biological Science, Graduate School of Science, Osaka Prefecture University, 1-2, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570, Japan.
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12
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Elustondo F, Chintalapudi V, Clark JS. A Short Sequence for the Iterative Synthesis of Fused Polyethers. Helv Chim Acta 2019. [DOI: 10.1002/hlca.201900161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Frédéric Elustondo
- School of ChemistryUniversity of Nottingham, University Park Nottingham NG7 2RD United Kingdom
| | - Venkaiah Chintalapudi
- School of Chemistry, Joseph Black BuildingUniversity of Glasgow, University Avenue Glasgow G12 8QQ United Kingdom
| | - J. Stephen Clark
- School of Chemistry, Joseph Black BuildingUniversity of Glasgow, University Avenue Glasgow G12 8QQ United Kingdom
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13
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Saito F, Trapp N, Bode JW. Iterative Assembly of Polycyclic Saturated Heterocycles from Monomeric Building Blocks. J Am Chem Soc 2019; 141:5544-5554. [PMID: 30845799 DOI: 10.1021/jacs.9b01537] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Polycyclic saturated heterocycles with predictable shapes and structures are assembled by iterative couplings of bifunctional stannyl amine protocol (SnAP) reagents and a single morpholine-forming assembly reaction. Combinations of just a few monomers enable the programmable construction of rotationally restricted, nonplanar heterocyclic arrays with discrete sizes and molecular shapes. The three-dimensional structures of these constrained scaffolds can be quickly and reliably predicted by DFT calculations and the target structures immediately decompiled into the constituent building blocks and assembly sequences. As a demonstration, in silico combinations of the building blocks predict saturated heptacyclic structures with elementary shapes including helices, S-turns and U-turns, which are synthesized in 5-6 steps from the monomers using just three chemical reactions.
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Affiliation(s)
- Fumito Saito
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences , ETH-Zürich , 8093 Zürich , Switzerland
| | - Nils Trapp
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences , ETH-Zürich , 8093 Zürich , Switzerland
| | - Jeffrey W Bode
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences , ETH-Zürich , 8093 Zürich , Switzerland
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14
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Oishi T. Design and Synthesis of Artificial Ladder-Shaped Polyethers for Exploring Biological Functions. HETEROCYCLES 2019. [DOI: 10.3987/rev-18-sr(f)1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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15
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Becker MR, Watson RB, Schindler CS. Beyond olefins: new metathesis directions for synthesis. Chem Soc Rev 2018; 47:7867-7881. [PMID: 30335106 DOI: 10.1039/c8cs00391b] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The olefin-olefin metathesis reaction has emerged as one of the most important carbon-carbon bond-forming reactions, as illustrated by its wide use in the synthesis of complex molecules, natural products and pharmaceuticals. The corresponding metathesis reaction between carbonyls and olefins or alkynes similarly allows for the formation of carbon-carbon bonds. Although these variants are far less developed and utilized in organic synthesis, they possess attractive qualities that have prompted chemists to incorporate and explore these modes of reactivity in complex molecule synthesis. This review highlights selected examples of carbonyl-olefin and carbonyl-alkyne metathesis reactions in organic synthesis, in particular in the total synthesis of natural products and complex molecules, and provides an overview of current advantages and limitations.
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Affiliation(s)
- Marc R Becker
- Department of Chemistry, University of Michigan, Willard Henry Dow Laboratory, 930 North University Avenue, Ann Arbor, Michigan 48109, USA.
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16
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Soliño L, Costa PR. Differential toxin profiles of ciguatoxins in marine organisms: Chemistry, fate and global distribution. Toxicon 2018; 150:124-143. [DOI: 10.1016/j.toxicon.2018.05.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/11/2018] [Accepted: 05/13/2018] [Indexed: 01/03/2023]
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17
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Tsumuraya T, Sato T, Hirama M, Fujii I. Highly Sensitive and Practical Fluorescent Sandwich ELISA for Ciguatoxins. Anal Chem 2018; 90:7318-7324. [PMID: 29770692 DOI: 10.1021/acs.analchem.8b00519] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ciguatera fish poisoning (CFP) caused by the consumption of fish that have accumulated ciguatoxins (CTXs) affects more than 50000 people annually. The spread of CFP causes enormous damage to public health, fishery resources, and the economies of tropical and subtropical endemic regions. The difficulty in avoiding CFP arises from the lack of sensitive and reliable analytical methods for the detection and quantification of CTXs in contaminated fish, along with the normal appearance, smell, and taste of fish contaminated with the causative toxins. Thus, an accurate, sensitive, routine, and portable detection method for CTXs is urgently required. We have successfully developed a highly sensitive fluorescent sandwich ELISA, which can detect, differentiate, and quantify four major CTX congeners (CTX1B, CTX3C, 51-hydroxyCTX3C, and 54-deoxyCTX1B) with a detection limit of less than 1 pg/mL. The ELISA protocol, using one microtiter plate coated with two mAbs (10C9 and 3G8), and ALP-linked 8H4, can detect any of the four CTX congeners in a single operation. CTX1B spiked into fish at the FDA guidance level of 0.01 ppb CTX1B equivalent toxicity in fish from Pacific regions was also proven to be reliably detected by this ELISA. Furthermore, the efficiency of extraction/purification procedures and the matrix effect of contaminants in fish were evaluated in detail, since pretreatment and matrix effects are critical for ELISA analysis.
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Affiliation(s)
- Takeshi Tsumuraya
- Department of Biological Science, Graduate School of Science , Osaka Prefecture University , Osaka 599-8570 , Japan
| | - Takeshi Sato
- Cell Science Inc. , Aoba-ku, Sendai , Miyagi 989-3212 , Japan
| | - Masahiro Hirama
- Department of Biological Science, Graduate School of Science , Osaka Prefecture University , Osaka 599-8570 , Japan
| | - Ikuo Fujii
- Department of Biological Science, Graduate School of Science , Osaka Prefecture University , Osaka 599-8570 , Japan
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Tanaka T, Asakura H, Fujiwara R, Kumamoto K, Izuka H, Shiroma K, Takamura H, Kadota I. Improved Synthesis of the A–E Ring Segment of Ciguatoxin CTX3C by Using Intramolecular Allylations. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2018. [DOI: 10.1246/bcsj.20170390] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Tokihiro Tanaka
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kitaku, Okayama 700-8530, Japan
| | - Hiroki Asakura
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kitaku, Okayama 700-8530, Japan
| | - Rie Fujiwara
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kitaku, Okayama 700-8530, Japan
| | - Kentaro Kumamoto
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kitaku, Okayama 700-8530, Japan
| | - Hiroaki Izuka
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kitaku, Okayama 700-8530, Japan
| | - Kengo Shiroma
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kitaku, Okayama 700-8530, Japan
| | - Hiroyoshi Takamura
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kitaku, Okayama 700-8530, Japan
| | - Isao Kadota
- Department of Chemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kitaku, Okayama 700-8530, Japan
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Saito T, Fujiwara K, Sano Y, Sato T, Kondo Y, Akiba U, Ishigaki Y, Katoono R, Suzuki T. An improved synthesis of the C42–C52 segment of ciguatoxin 3C. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2018.02.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Shmukler YB, Nikishin DA. Ladder-Shaped Ion Channel Ligands: Current State of Knowledge. Mar Drugs 2017; 15:E232. [PMID: 28726749 PMCID: PMC5532674 DOI: 10.3390/md15070232] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 07/07/2017] [Accepted: 07/14/2017] [Indexed: 12/20/2022] Open
Abstract
Ciguatoxins (CTX) and brevetoxins (BTX) are polycyclic ethereal compounds biosynthesized by the worldwide distributed planktonic and epibenthic dinoflagellates of Gambierdiscus and Karenia genera, correspondingly. Ciguatera, evoked by CTXs, is a type of ichthyosarcotoxism, which involves a variety of gastrointestinal and neurological symptoms, while BTXs cause so-called neurotoxic shellfish poisoning. Both types of toxins are reviewed together because of similar mechanisms of their action. These are the only molecules known to activate voltage-sensitive Na⁺-channels in mammals through a specific interaction with site 5 of its α-subunit and may compete for it, which results in an increase in neuronal excitability, neurotransmitter release and impairment of synaptic vesicle recycling. Most marine ciguatoxins potentiate Nav channels, but a considerable number of them, such as gambierol and maitotoxin, have been shown to affect another ion channel. Although the extrinsic function of these toxins is probably associated with the function of a feeding deterrent, it was suggested that their intrinsic function is coupled with the regulation of photosynthesis via light-harvesting complex II and thioredoxin. Antagonistic effects of BTXs and brevenal may provide evidence of their participation as positive and negative regulators of this mechanism.
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Affiliation(s)
- Yuri B Shmukler
- Group of Embryophysiology, N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26, Vavilov st, 119334 Moscow, Russia.
| | - Denis A Nikishin
- Group of Embryophysiology, N.K. Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 26, Vavilov st, 119334 Moscow, Russia.
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Biooxidation of Ciguatoxins Leads to Species-Specific Toxin Profiles. Toxins (Basel) 2017; 9:toxins9070205. [PMID: 28661447 PMCID: PMC5535152 DOI: 10.3390/toxins9070205] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 11/17/2022] Open
Abstract
Ciguatoxins (CTXs) contaminate fish worldwide and cause the foodborne illness ciguatera. In the Pacific, these toxins are produced by the dinoflagellate Gambierdiscus toxicus, which accumulates in fish through the food chain and undergoes oxidative modification, giving rise to numerous analogs. In this study, we examined the oxidation of CTXs in vitro with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis using reference toxins, and found that CTX4A, CTX4B, and CTX3C, which are produced by the alga, are oxidized to the analogs found in fish, namely CTX1B, 52-epi-54-deoxyCTX1B, 54-deoxyCTX1B, 2-hydroxyCTX3C, and 2,3-dihydroxyCTX3C. This oxidation was catalyzed by human CYP3A4, fish liver S9 fractions, and microsomal fractions prepared from representative ciguateric fishes (Lutjanus bohar, L. monostigumus, and Oplegnathus punctatus). In addition, fish liver S9 fractions prepared from non-ciguateric fishes (L. gibbus and L. fulviflamma) in Okinawa also converted CTX4A and CTX4B to CTX1B, 54-deoxyCTX1B, and 52-epi-54-deoxyCTX1B in vitro. This is the first study to demonstrate the enzymatic oxidation of these toxins, and provides insight into the mechanism underlying the development of species-specific toxin profiles and the fate of these toxins in humans and fish.
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Coccini T, Caloni F, De Simone U. Human neuronal cell based assay: A new in vitro model for toxicity evaluation of ciguatoxin. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2017; 52:200-213. [PMID: 28437641 DOI: 10.1016/j.etap.2017.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/31/2017] [Accepted: 04/02/2017] [Indexed: 06/07/2023]
Abstract
Ciguatoxins (CTXs) are emerging marine neurotoxins representing the main cause of ciguatera fish poisoning, an intoxication syndrome which configures a health emergency and constitutes an evolving issue constantly changing due to new vectors and derivatives of CTXs, as well as their presence in new non-endemic areas. The study applied the neuroblastoma cell model of human origin (SH-SY5Y) to evaluate species-specific mechanistic information on CTX toxicity. Metabolic functionality, cell morphology, cytosolic Ca2+i responses, neuronal cell growth and proliferation were assessed after short- (4-24h) and long-term exposure (10days) to P-CTX-3C. In SH-SY5Y, P-CTX-3C displayed a powerful cytotoxicity requiring the presence of both Veratridine and Ouabain. SH-SY5Y were very sensitive to Ouabain: 10 and 0.25nM appeared the optimal concentrations, for short- and long-term toxicity studies, respectively, to be used in co-incubation with Veratridine (25μM), simulating the physiological and pathological endogenous Ouabain levels in humans. P-CTX-3C cytotoxic effect, on human neurons co-incubated with OV (Ouabain+Veratridine) mix, was expressed starting from 100pM after short- and 25pM after long-term exposure. Notably, P-CTX-3C alone at 25nM induced cytotoxicity after 24h and prolonged exposure. This human brain-derived cell line appears a suitable cell-based-model to evaluate cytotoxicity of CTX present in marine food contaminated at low toxic levels and to characterize the toxicological profile of other/new congeners.
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Affiliation(s)
- Teresa Coccini
- Laboratory of Clinical and Experimental Toxicology, Poison Control Centre, Toxicology Unit, Maugeri Clinical Scientific Institutes S.p.A.-BS, IRCCS Pavia, Pavia Italy.
| | - Francesca Caloni
- Department of Veterinary Medicine (DIMEVET), Università degli Studi di Milano, Milano, Italy
| | - Uliana De Simone
- Laboratory of Clinical and Experimental Toxicology, Poison Control Centre, Toxicology Unit, Maugeri Clinical Scientific Institutes S.p.A.-BS, IRCCS Pavia, Pavia Italy
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HIRAMA M. Total synthesis and related studies of large, strained, and bioactive natural products. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2016; 92:290-329. [PMID: 27725470 PMCID: PMC5243947 DOI: 10.2183/pjab.92.290] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 08/10/2016] [Indexed: 06/06/2023]
Abstract
Our chemical syntheses and related scientific investigations of natural products with complex architectures and powerful biological activities are described, focusing on the very large 3 nm-long polycyclic ethers called the ciguatoxins, highly strained and labile chromoprotein antitumor antibiotics featuring nine-membered enediyne cores, and extremely potent anthelmintic macrolides called the avermectins.
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Affiliation(s)
- Masahiro HIRAMA
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, Japan
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Kadota I, Sato Y, Fujita N, Takamura H, Yamamoto Y. Convergent synthesis of the EFGH ring system of ciguatoxin CTX3C. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.04.106] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Yamashita S, Takeuchi K, Koyama T, Inoue M, Hayashi Y, Hirama M. Practical route to the left wing of CTX1B and total syntheses of CTX1B and 54-deoxyCTX1B. Chemistry 2014; 21:2621-8. [PMID: 25529606 DOI: 10.1002/chem.201405629] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Indexed: 11/07/2022]
Abstract
Ciguatoxins, the principal causative agents of ciguatera seafood poisoning, are extremely large polycyclic ethers. We report herein a reliable route for constructing the left wing of CTX1B, which possesses the acid/base/oxidant-sensitive bisallylic ether moiety, by a 6-exo radical cyclization/ring-closing metathesis strategy. This new route enabled us to achieve the second-generation total synthesis of CTX1B and the first synthesis of 54-deoxyCTX1B.
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Affiliation(s)
- Shuji Yamashita
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan).
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Sasaki M, Fuwa H. Total synthesis and complete structural assignment of gambieric acid A, a large polycyclic ether marine natural product. CHEM REC 2014; 14:678-703. [PMID: 25092231 DOI: 10.1002/tcr.201402052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Indexed: 12/30/2022]
Abstract
More than thirty years after the discovery of polycyclic ether marine natural products, they continue to receive intense attention from the chemical, biological, and pharmacological communities because of their potent biological activities and highly complex molecular architectures. Gambieric acids are intriguing polycyclic ethers that exhibit potent antifungal activity with minimal toxicity against mammals. Despite the recent advances in the synthesis of this class of natural products, gambieric acids remain unconquered due to their daunting structural complexity, which poses a formidable synthetic challenge to organic chemists. This paper reviews our long-term studies on the total synthesis, complete configurational reassignment, and structure-activity relationships of gambieric acid A over the last decade.
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Affiliation(s)
- Makoto Sasaki
- Graduate School of Life Sciences, Tohoku University, Katahira, Aoba-ku, Sendai 980-8577, Japan.
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28
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The Influence of Structure on Reactivity in Alkene Metathesis. ADVANCES IN PHYSICAL ORGANIC CHEMISTRY 2014. [DOI: 10.1016/b978-0-12-800256-8.00002-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Kadota I, Shiroma K, Asakura H, Tanaka T, Takamura H. Improved Synthesis of the A-E Ring Segment of Ciguatoxin CTX3C. HETEROCYCLES 2014. [DOI: 10.3987/com-13-s(s)106] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Domon D, Fujiwara K, Kawamura N, Katoono R, Kawai H, Suzuki T. A New Variant of Fused Cyclic Ether Synthesis Based on Ireland-Claisen Rearrangement and RCM. Nat Prod Commun 2013. [DOI: 10.1177/1934578x1300800718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A new variant of fused cyclic ether synthesis based on Ireland-Claisen rearrangement and ring-closing olefin metathesis (RCM) was developed. The Ireland-Claisen rearrangement and ring-closing olefin metathesis (RCM) was developed. The Ireland-Claisen rearrangement of a ( Z)-3-alkoxyprop-2-en-1-yl glycolate ester having a cyclic ether on the oxygen at C3 of the ( Z)-prop-2-en-1-yl group stereoselectively produced an anti-α,β-dialkoxyester which was successfully transformed to a fused bicyclic ether via a reaction sequence including RCM.
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Affiliation(s)
- Daisuke Domon
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Kenshu Fujiwara
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Natsumi Kawamura
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Ryo Katoono
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Hidetoshi Kawai
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Takanori Suzuki
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
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31
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Nogoshi K, Domon D, Fujiwara K, Kawamura N, Katoono R, Kawai H, Suzuki T. An Ireland–Claisen rearrangement/RCM based approach for the construction of the EF-ring of ciguatoxin 3C. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2012.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Sakai T, Sugimoto A, Tatematsu H, Mori Y. Divergent synthesis of trans-fused polycyclic ethers by a convergent oxiranyl anion strategy. J Org Chem 2012; 77:11177-91. [PMID: 23214941 DOI: 10.1021/jo302267f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Octacyclic polyethers that correspond to the CDEFGHIJ-ring system of yessotoxin as well as G- and/or I-ring-modified analogues were synthesized in a divergent manner, starting from a common intermediate, using an [X + 2 + Y]-type convergent method. Reaction of a triflate with the oxiranyl anion generated from an epoxy sulfone, followed by ring expansion, allowed for the incorporation of medium-sized ring ethers into the key intermediate. Subsequent acetal formation and reductive etherification afforded various octacycles containing seven- and eight-membered ether rings.
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Affiliation(s)
- Takeo Sakai
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
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33
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34
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Kadota I, Shiroma K, Takamura H. Synthesis of the E Ring Segment of Ciguatoxin CTX3C via the Negishi Coupling of Cyclic Ketene Acetal Triflate. HETEROCYCLES 2012. [DOI: 10.3987/com-12-s(n)117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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35
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Ishiwata A, Ito Y. Intramolecular Aglycon Delivery and Its Application to Stereoselective Synthesis of Glycans. J SYN ORG CHEM JPN 2012. [DOI: 10.5059/yukigoseikyokaishi.70.382] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Yogi K, Oshiro N, Inafuku Y, Hirama M, Yasumoto T. Detailed LC-MS/MS Analysis of Ciguatoxins Revealing Distinct Regional and Species Characteristics in Fish and Causative Alga from the Pacific. Anal Chem 2011; 83:8886-91. [DOI: 10.1021/ac200799j] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kentaro Yogi
- Okinawa Science and Technology Promotion Center, 12-75 Suzaki, Uruma, Okinawa 904-2234, Japan
- Okinawa Prefectural Institute of Health and Environment, 2085 Aza-Ozato, Ozato, Nanjo, Okinawa 901-1202, Japan
| | - Naomasa Oshiro
- Okinawa Prefectural Institute of Health and Environment, 2085 Aza-Ozato, Ozato, Nanjo, Okinawa 901-1202, Japan
| | - Yasuo Inafuku
- Okinawa Prefectural Institute of Health and Environment, 2085 Aza-Ozato, Ozato, Nanjo, Okinawa 901-1202, Japan
| | - Masahiro Hirama
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Takeshi Yasumoto
- Japan Food Research Laboratories, 6-11-10 Nagayama, Tama, Tokyo 206-0025, Japan
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37
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Inoue M. Total synthesis and functional analysis of non-ribosomal peptides. CHEM REC 2011; 11:284-94. [DOI: 10.1002/tcr.201100014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Indexed: 11/07/2022]
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Takamura H, Nishiuma N, Abe T, Kadota I. Convergent Synthesis of the HIJKLM Ring System of Ciguatoxin CTX3C. Org Lett 2011; 13:4704-7. [DOI: 10.1021/ol2019136] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hiroyoshi Takamura
- Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan
| | - Naoki Nishiuma
- Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan
| | - Takashi Abe
- Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan
| | - Isao Kadota
- Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan
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Abstract
This short account discusses the awesome power of metathesis which has profoundly changed the practice of natural product synthesis during the last decade. Since a comprehensive coverage is beyond the scope of this highlight article, I shall focus on the conceptual framework and on significant advances since the turn of the century.
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Affiliation(s)
- Alois Fürstner
- Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim/Ruhr, Germany.
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41
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Yamaoka K, Inoue M, Hirama M. A study on mechanisms of toxic actions of ciguatoxins: existence of functional relationship between CTX3C and charged residues of voltage sensors in Nav1.4 sodium channel. Forensic Toxicol 2011. [DOI: 10.1007/s11419-011-0113-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Maitotoxin holds a special place in the annals of natural products chemistry as the largest and most toxic secondary metabolite known to date. Its fascinating, ladder-like, polyether molecular structure and diverse spectrum of biological activities elicited keen interest from chemists and biologists who recognized its uniqueness and potential as a probe and inspiration for research in chemistry and biology. Synthetic studies in the area benefited from methodologies and strategies that were developed as part of chemical synthesis programs directed toward the total synthesis of some of the less complex members of the polyether marine biotoxin class, of which maitotoxin is the flagship. This account focuses on progress made in the authors' laboratories in the synthesis of large maitotoxin domains with emphasis on methodology development, strategy design, and structural comparisons of the synthesized molecules with the corresponding regions of the natural product. The article concludes with an overview of maitotoxin's biological profile and future perspectives.
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Affiliation(s)
- K. C. Nicolaou
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037 (USA), Fax: (+1) 858-784-2469, and Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (USA)
| | - Robert J. Aversa
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037 (USA), Fax: (+1) 858-784-2469, and Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093 (USA)
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Yamashita S, Ishihara Y, Morita H, Uchiyama J, Takeuchi K, Inoue M, Hirama M. Stereoselective 6-exo radical cyclization using cis-vinyl sulfoxide: practical total synthesis of CTX3C. JOURNAL OF NATURAL PRODUCTS 2011; 74:357-364. [PMID: 21250701 DOI: 10.1021/np100729d] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Ciguatoxins, the principal causative toxins of ciguatera seafood poisoning, are large ladder-like polycyclic ethers. We report a highly stereoselective 6-exo radical cyclization/ring-closing olefin metathesis sequence to construct the syn/trans-fused polyether system. The new method was applied to the practical synthesis of ciguatoxin CTX3C.
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Affiliation(s)
- Shuji Yamashita
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan.
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Pérez S, Vale C, Alonso E, Alfonso C, Rodríguez P, Otero P, Alfonso A, Vale P, Hirama M, Vieytes MR, Botana LM. A comparative study of the effect of ciguatoxins on voltage-dependent Na+ and K+ channels in cerebellar neurons. Chem Res Toxicol 2011; 24:587-96. [PMID: 21351754 DOI: 10.1021/tx200043j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Ciguatera is a global disease caused by the consumption of certain warm-water fish (ciguateric fish) that have accumulated orally effective levels of sodium channel activator toxins (ciguatoxins) through the marine food chain. The effect of ciguatoxin standards and contaminated ciguatoxin samples was evaluated by electrophysiological recordings in cultured cerebellar neurons. The toxins affected both voltage-gated sodium (Nav) and potassium channels (Kv) although with different potencies. CTX 3C was the most active toxin blocking the peak inward sodium currents, followed by P-CTX 1B and 51-OH CTX 3C. In contrast, P-CTX 1B was more effective in blocking potassium currents. The analysis of six different samples of contaminated fish, in which a ciguatoxin analogue of mass 1040.6, not identical with the standard 51-OH CTX 3C, was the most prevalent compound, indicated an additive effect of the different ciguatoxins present in the samples. The results presented here constitute the first comparison of the potencies of three different purified ciguatoxins on sodium and potassium channels in the same neuronal preparation and indicate that electrophysiological recordings from cultured cerebellar neurons may provide a valuable tool to detect and quantify ciguatoxins in the very low nanomolar range.
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Affiliation(s)
- Sheila Pérez
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n, Lugo, Spain
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Caillaud A, de la Iglesia P, Darius HT, Pauillac S, Aligizaki K, Fraga S, Chinain M, Diogène J. Update on methodologies available for ciguatoxin determination: perspectives to confront the onset of ciguatera fish poisoning in Europe. Mar Drugs 2010; 8:1838-907. [PMID: 20631873 PMCID: PMC2901828 DOI: 10.3390/md8061838] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 05/18/2010] [Accepted: 06/10/2010] [Indexed: 11/29/2022] Open
Abstract
Ciguatera fish poisoning (CFP) occurs mainly when humans ingest finfish contaminated with ciguatoxins (CTXs). The complexity and variability of such toxins have made it difficult to develop reliable methods to routinely monitor CFP with specificity and sensitivity. This review aims to describe the methodologies available for CTX detection, including those based on the toxicological, biochemical, chemical, and pharmaceutical properties of CTXs. Selecting any of these methodological approaches for routine monitoring of ciguatera may be dependent upon the applicability of the method. However, identifying a reference validation method for CTXs is a critical and urgent issue, and is dependent upon the availability of certified CTX standards and the coordinated action of laboratories. Reports of CFP cases in European hospitals have been described in several countries, and are mostly due to travel to CFP endemic areas. Additionally, the recent detection of the CTX-producing tropical genus Gambierdiscus in the eastern Atlantic Ocean of the northern hemisphere and in the Mediterranean Sea, as well as the confirmation of CFP in the Canary Islands and possibly in Madeira, constitute other reasons to study the onset of CFP in Europe [1]. The question of the possible contribution of climate change to the distribution of toxin-producing microalgae and ciguateric fish is raised. The impact of ciguatera onset on European Union (EU) policies will be discussed with respect to EU regulations on marine toxins in seafood. Critical analysis and availability of methodologies for CTX determination is required for a rapid response to suspected CFP cases and to conduct sound CFP risk analysis.
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Affiliation(s)
- Amandine Caillaud
- IRTA, Ctra. Poble Nou, Km 5,5. 43540 Sant Carles de la Ràpita, Spain; E-Mails: (A.C.); (P.I.)
| | - Pablo de la Iglesia
- IRTA, Ctra. Poble Nou, Km 5,5. 43540 Sant Carles de la Ràpita, Spain; E-Mails: (A.C.); (P.I.)
| | - H. Taiana Darius
- Laboratoire des micro-algues toxiques, Institut Louis Malardé, BP30, 98713 Papeete Tahiti, French Polynesia; E-Mails: (H.T.D.); (M.C.)
| | - Serge Pauillac
- Institut Pasteur, 25-28 rue du docteur Roux, 75 015 Paris, France; E-Mail: (S.P.)
| | - Katerina Aligizaki
- Department of Botany, School of Biology, Faculty of Sciences, Aristotle University, 54 124 Thessaloniki, Greece; E-Mail: (K.A.)
| | - Santiago Fraga
- Instituto Español de Oceanografía, Subida a Radio Faro, 50, 36390 Vigo, Spain; E-Mail: (S.F.)
| | - Mireille Chinain
- Laboratoire des micro-algues toxiques, Institut Louis Malardé, BP30, 98713 Papeete Tahiti, French Polynesia; E-Mails: (H.T.D.); (M.C.)
| | - Jorge Diogène
- IRTA, Ctra. Poble Nou, Km 5,5. 43540 Sant Carles de la Ràpita, Spain; E-Mails: (A.C.); (P.I.)
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Hirama M, Yamashita S, Iijima N, Shida T. Stereoselective Synthesis of Caribbean Ciguatoxin M-Ring Using [2+2] Photocyclization. HETEROCYCLES 2010. [DOI: 10.3987/com-10-s(e)61] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Ishiwata A, Lee YJ, Ito Y. Recent advances in stereoselective glycosylation through intramolecular aglycon delivery. Org Biomol Chem 2010; 8:3596-608. [DOI: 10.1039/c004281a] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Ishihara Y, Lee N, Oshiro N, Matsuoka S, Yamashita S, Inoue M, Hirama M. The first F-ring modified ciguatoxin analogue showing significant toxicity. Chem Commun (Camb) 2010; 46:2968-70. [DOI: 10.1039/b924375e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Isobe M, Hamajima A. Ciguatoxin: developing the methodology for total synthesis. Nat Prod Rep 2010; 27:1204-26. [DOI: 10.1039/b919467n] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Nakata T. SmI2-induced reductive cyclizations for the synthesis of cyclic ethers and applications in natural product synthesis. Chem Soc Rev 2010; 39:1955-72. [DOI: 10.1039/b902737h] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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