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Mudge EM, Meija J, Uhlig S, Robertson A, McCarron P, Miles CO. Production and stability of Oxygen-18 labeled Caribbean ciguatoxins and gambierones. Toxicon 2022; 211:11-20. [PMID: 35300989 DOI: 10.1016/j.toxicon.2022.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 02/25/2022] [Accepted: 03/10/2022] [Indexed: 10/18/2022]
Abstract
Ciguatoxins (CTXs) and gambierones are ladder-shaped polyethers associated with ciguatera poisoning and Gambierdiscus spp. Several of these compounds contain carbonyl or hemiketal groups, which have the potential to exchange with 18O-labeled water under acidic conditions. The effects of solvent composition and acid on the rate of exchange and on the stability of the labels at various pH values were assessed to optimize the incorporation of 18O into Caribbean ciguatoxin-1 and -2 (C-CTX1/2), gambierone, and 44-methylgambierone. LC-HRMS results showed that 18O-labeling occurred at the hydroxy group of the hemiketal at C-56 in C-CTX1/2, and at the hydroxy group of the hemiketal at C-4 and the ketone at C-40 in gambierones. Labeling occurred very rapidly (complete in <30 min) for C-CTX1/2, and more slowly (complete in ca. 16 h) for both gambierones. Labeled C-CTX1/2 was reduced with sodium borohydride to produce 18O-labeled C-CTX3/4. The incorporated 18O labels in the gambierones and C-CTXs were retained in aqueous solvent mixtures under neutral conditions in a short-term stability study, demonstrating that these 18O-labeled toxins have the potential to be used in isotope dilution and metabolism studies.
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Affiliation(s)
- Elizabeth M Mudge
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS, B3H 2Z1, Canada.
| | - Juris Meija
- Chemical Metrology, National Research Council, 1200 Montreal Road, Ottawa, ON, K1A 0R6, Canada
| | - Silvio Uhlig
- Toxinology Research Group, Norwegian Veterinary Institute, P.O. Box 64, 1431, Ås, Norway
| | - Alison Robertson
- School of Marine and Environmental Sciences, University of South Alabama, 600 Clinic Drive, Mobile, AL, 36688, USA; Marine Ecotoxicology, Dauphin Island Sea Lab, 101 Bienville Blvd, Dauphin Island, Dauphin Island, AL, 36528, USA
| | - Pearse McCarron
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS, B3H 2Z1, Canada
| | - Christopher O Miles
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS, B3H 2Z1, Canada
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Jiang ZP, Sun SH, Yu Y, Mándi A, Luo JY, Yang MH, Kurtán T, Chen WH, Shen L, Wu J. Discovery of benthol A and its challenging stereochemical assignment: opening up a new window for skeletal diversity of super-carbon-chain compounds. Chem Sci 2021; 12:10197-10206. [PMID: 34447528 PMCID: PMC8336589 DOI: 10.1039/d1sc02810c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 06/25/2021] [Indexed: 12/28/2022] Open
Abstract
Super-carbon-chain compounds (SCCCs) are marine organic molecules featuring long polyol carbon chains with numerous stereocenters. Polyol-polyene compounds (PPCs) and ladder-frame polyethers (LFPs) are two major families. It is highly challenging to establish the absolute configurations of SCCCs. In this century, few new SCCC families have been reported. Benthol A, an aberrant SCCC, was obtained from a South China Sea benthic dinoflagellate that should belong to a new taxon. Its planar structure and absolute configuration, containing thirty-five carbon stereocenters, were unambiguously established by a combination of extensive NMR spectroscopic investigations, periodate degradation of the 1,2-diol groups, ozonolysis of the carbon-carbon double bonds, J-based configurational analysis, NOE interactions, modified Mosher's MTPA ester method, and DFT-NMR 13C chemical-shift calculations aided by DP4+ statistical analysis. Benthol A displayed potent antimalarial activity against Plasmodium falciparum 3D7 parasites. This new molecule combines extraordinary structural features, particularly eight scattered ether rings on a C72 backbone chain, which places it within a new SCCC family between PPCs and LFPs, herein termed polyol-polyether compounds. This suggestion was strongly supported by principal component analysis. The discovery of benthol A does not only provide new insights into the untapped biosynthetic potential of marine dinoflagellates, but also opens up a new window for skeletal diversity of SCCCs.
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Affiliation(s)
- Zhong-Ping Jiang
- School of Pharmaceutical Sciences, Southern Medical University 1838 Guangzhou Avenue North Guangzhou 510515 P. R. China
| | - Shi-Hao Sun
- School of Pharmaceutical Sciences, Southern Medical University 1838 Guangzhou Avenue North Guangzhou 510515 P. R. China
| | - Yi Yu
- Marine Drugs Research Center, College of Pharmacy, Jinan University 601 Huangpu Avenue West Guangzhou 510632 P. R. China
| | - Attila Mándi
- Department of Organic Chemistry, University of Debrecen PO Box 400 4002 Debrecen Hungary
| | - Jiao-Yang Luo
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing 100193 P. R. China
| | - Mei-Hua Yang
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing 100193 P. R. China
| | - Tibor Kurtán
- Department of Organic Chemistry, University of Debrecen PO Box 400 4002 Debrecen Hungary
| | - Wen-Hua Chen
- School of Biotechnology and Health Sciences, Wuyi University Jiangmen Guangdong Province 529020 P. R. China
| | - Li Shen
- Marine Drugs Research Center, College of Pharmacy, Jinan University 601 Huangpu Avenue West Guangzhou 510632 P. R. China
| | - Jun Wu
- School of Pharmaceutical Sciences, Southern Medical University 1838 Guangzhou Avenue North Guangzhou 510515 P. R. China
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Wan X, Yao G, Liu Y, Chen J, Jiang H. Research Progress in the Biosynthetic Mechanisms of Marine Polyether Toxins. Mar Drugs 2019; 17:E594. [PMID: 31652489 PMCID: PMC6835853 DOI: 10.3390/md17100594] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/17/2019] [Accepted: 10/18/2019] [Indexed: 12/28/2022] Open
Abstract
Marine polyether toxins, mainly produced by marine dinoflagellates, are novel, complex, and diverse natural products with extensive toxicological and pharmacological effects. Owing to their harmful effects during outbreaks of marine red tides, as well as their potential value for the development of new drugs, marine polyether toxins have been extensively studied, in terms of toxicology, pharmacology, detection, and analysis, structural identification, as well as their biosynthetic mechanisms. Although the biosynthetic mechanisms of marine polyether toxins are still unclear, certain progress has been made. In this review, research progress and current knowledge on the biosynthetic mechanisms of polyether toxins are summarized, including the mechanisms of carbon skeleton deletion, pendant alkylation, and polyether ring formation, along with providing a summary of mined biosynthesis-related genes. Finally, future research directions and applications of marine polyether toxins are discussed.
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Affiliation(s)
- Xiukun Wan
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Ge Yao
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Yanli Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Jisheng Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Hui Jiang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
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Anttila M, Strangman W, York R, Tomas C, Wright JLC. Biosynthetic Studies of 13-Desmethylspirolide C Produced by Alexandrium ostenfeldii (= A. peruvianum): Rationalization of the Biosynthetic Pathway Following Incorporation of (13)C-Labeled Methionine and Application of the Odd-Even Rule of Methylation. JOURNAL OF NATURAL PRODUCTS 2016; 79:484-489. [PMID: 26641306 DOI: 10.1021/acs.jnatprod.5b00869] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Understanding the biosynthesis of dinoflagellate polyketides presents many unique challenges. Because of the remaining hurdles to dinoflagellate genome sequencing, precursor labeling studies remain the only viable way to investigate dinoflagellate biosynthesis. However, prior studies have shown that polyketide chain assembly does not follow any of the established processes. Additionally, acetate, the common precursor for polyketides, is frequently scrambled, thus compromising interpretation. These factors are further compounded by low production yields of the compounds of interest. A recent report on the biosynthesis of spirolides, a group belonging to the growing class of toxic spiroimines, provided some insight into the polyketide assembly process based on acetate labeling studies, but many details were left uncertain. By feeding (13)C methyl-labeled methionine to cultures of Alexandrium ostenfeldii, the producing organism of 13-desmethylspirolide C, and application of the odd-even methylation rule, the complete biosynthetic pathway has been established.
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Affiliation(s)
- Matthew Anttila
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
| | - Wendy Strangman
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
| | - Robert York
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
| | - Carmelo Tomas
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
| | - Jeffrey L C Wright
- UNCW Center for Marine Science , 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, United States
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Sun P, Leeson C, Zhi X, Leng F, Pierce RH, Henry MS, Rein KS. Characterization of an epoxide hydrolase from the Florida red tide dinoflagellate, Karenia brevis. PHYTOCHEMISTRY 2016; 122:11-21. [PMID: 26626160 PMCID: PMC4724521 DOI: 10.1016/j.phytochem.2015.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 10/19/2015] [Accepted: 11/05/2015] [Indexed: 05/11/2023]
Abstract
Epoxide hydrolases (EH, EC 3.3.2.3) have been proposed to be key enzymes in the biosynthesis of polyether (PE) ladder compounds such as the brevetoxins which are produced by the dinoflagellate Karenia brevis. These enzymes have the potential to catalyze kinetically disfavored endo-tet cyclization reactions. Data mining of K. brevis transcriptome libraries revealed two classes of epoxide hydrolases: microsomal and leukotriene A4 (LTA4) hydrolases. A microsomal EH was cloned and expressed for characterization. The enzyme is a monomeric protein with molecular weight 44kDa. Kinetic parameters were evaluated using a variety of epoxide substrates to assess substrate selectivity and enantioselectivity, as well as its potential to catalyze the critical endo-tet cyclization of epoxy alcohols. Monitoring of EH activity in high and low toxin producing cultures of K. brevis over a three week period showed consistently higher activity in the high toxin producing culture implicating the involvement of one or more EH in brevetoxin biosynthesis.
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Affiliation(s)
- Pengfei Sun
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - Cristian Leeson
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Xiaoduo Zhi
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA
| | - Fenfei Leng
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - Richard H Pierce
- Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236, USA.
| | - Michael S Henry
- Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236, USA.
| | - Kathleen S Rein
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
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Polyketide synthesis genes associated with toxin production in two species of Gambierdiscus (Dinophyceae). BMC Genomics 2015; 16:410. [PMID: 26016672 PMCID: PMC4445524 DOI: 10.1186/s12864-015-1625-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 05/07/2015] [Indexed: 11/10/2022] Open
Abstract
Background Marine microbial protists, in particular, dinoflagellates, produce polyketide toxins with ecosystem-wide and human health impacts. Species of Gambierdiscus produce the polyether ladder compounds ciguatoxins and maitotoxins, which can lead to ciguatera fish poisoning, a serious human illness associated with reef fish consumption. Genes associated with the biosynthesis of polyether ladder compounds are yet to be elucidated, however, stable isotope feeding studies of such compounds consistently support their polyketide origin indicating that polyketide synthases are involved in their biosynthesis. Results Here, we report the toxicity, genome size, gene content and transcriptome of Gambierdiscus australes and G. belizeanus. G. australes produced maitotoxin-1 and maitotoxin-3, while G. belizeanus produced maitotoxin-3, for which cell extracts were toxic to mice by IP injection (LD50 = 3.8 mg kg-1). The gene catalogues comprised 83,353 and 84,870 unique contigs, with genome sizes of 32.5 ± 3.7 Gbp and 35 ± 0.88 Gbp, respectively, and are amongst the most comprehensive yet reported from a dinoflagellate. We found three hundred and six genes involved in polyketide biosynthesis, including one hundred and ninty-two ketoacyl synthase transcripts, which formed five unique phylogenetic clusters. Conclusions Two clusters were unique to these maitotoxin-producing dinoflagellate species, suggesting that they may be associated with maitotoxin biosynthesis. This work represents a significant step forward in our understanding of the genetic basis of polyketide production in dinoflagellates, in particular, species responsible for ciguatera fish poisoning. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1625-y) contains supplementary material, which is available to authorized users.
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Van Wagoner RM, Satake M, Wright JLC. Polyketide biosynthesis in dinoflagellates: what makes it different? Nat Prod Rep 2014; 31:1101-37. [DOI: 10.1039/c4np00016a] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Abstract
This review covers the literature published in 2012 for marine natural products, with 1035 citations (673 for the period January to December 2012) 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 (1241 for 2012), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.
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Affiliation(s)
- John W Blunt
- Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
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Satake M, Shirai T, Takimoto Y, Kuranaga T, Tachibana K, G. Baden D, L. C. Wright J. Synthesis and Cyclization of a Proposed Biosynthetic Epoxy Intermediate of a Marine Monocyclic Ether Amide, Brevisamide. HETEROCYCLES 2014. [DOI: 10.3987/com-13-12880] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Watanabe R, Uchida H, Suzuki T, Matsushima R, Nagae M, Toyohara Y, Satake M, Oshima Y, Inoue A, Yasumoto T. Gambieroxide, a novel epoxy polyether compound from the dinoflagellate Gambierdiscus toxicus GTP2 strain. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.10.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Morimoto Y, Takeuchi E, Kambara H, Kodama T, Tachi Y, Nishikawa K. Biomimetic epoxide-opening cascades of oxasqualenoids triggered by hydrolysis of the terminal epoxide. Org Lett 2013; 15:2966-9. [PMID: 23721415 DOI: 10.1021/ol401081e] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The biomimetic epoxide-opening cascades from squalene polyepoxides 4-6 to triterpene polyethers (oxasqualenoids) teurilene (1), glabrescol (2), and omaezakianol (3), respectively, were reproduced in a single event by chemical reaction. These cascades proceeded through the 5-exo tandem cyclization triggered by Brønsted acid-catalyzed hydrolysis of the terminal epoxide, mimicking the direct hydrolysis mechanism of epoxide hydrolases.
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Affiliation(s)
- Yoshiki Morimoto
- Department of Chemistry, Graduate School of Science, Osaka City University , Sumiyoshi-ku, Osaka 558-8585, Japan
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