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Wu K, Kang K, Liu D, Zhang C, Wang X, Zhang M, Li Q. Gold-catalyzed endo-selective Ring-opening of Epoxides and its Application in Construction of Poly-ethers. Chemistry 2024; 30:e202400234. [PMID: 38273816 DOI: 10.1002/chem.202400234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 01/23/2024] [Indexed: 01/27/2024]
Abstract
Tetrahydropyran and tetrahydropyran-fused poly-ethers scaffolds are found in many classes of natural products and medicinally relevant small molecules. Here we describe a catalytic system for 6-endo selective ring-opening of epoxides by Au(I) or Au(III) catalyst that provides rapid access to various tetrahydropyran-derived motifs. It also could efficiently construct the subunits of marine ladder-like poly-ethers through emulating the Nakanishi's hypothesis on the biosynthesis of these toxins. The synthetic utility of this method is also demonstrated in the preparation of the tricyclic core of tetrahydropyran-containing macrolide natural products lituarines A-C.
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Affiliation(s)
- Kehuan Wu
- Small-Molecule Drug Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, 201203, China
| | - Kaiwen Kang
- Small-Molecule Drug Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Dan Liu
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Chiyue Zhang
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Xinyu Wang
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Miaocheng Zhang
- Small-Molecule Drug Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qi Li
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, 210023, China
- Small-Molecule Drug Research Center, Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, 201203, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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2
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Haq S, Oyler BL, Williams E, Khan MM, Goodlett DR, Bachvaroff T, Place AR. Investigating A Multi-Domain Polyketide Synthase in Amphidinium carterae. Mar Drugs 2023; 21:425. [PMID: 37623706 PMCID: PMC10455422 DOI: 10.3390/md21080425] [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: 05/31/2023] [Revised: 07/14/2023] [Accepted: 07/25/2023] [Indexed: 08/26/2023] Open
Abstract
Dinoflagellates are unicellular organisms that are implicated in harmful algal blooms (HABs) caused by potent toxins that are produced through polyketide synthase (PKS) pathways. However, the exact mechanisms of toxin synthesis are unknown due to a lack of genomic segregation of fat, toxins, and other PKS-based pathways. To better understand the underlying mechanisms, the actions and expression of the PKS proteins were investigated using the toxic dinoflagellate Amphidinium carterae as a model. Cerulenin, a known ketosynthase inhibitor, was shown to reduce acetate incorporation into all fat classes with the toxins amphidinol and sulpho-amphidinol. The mass spectrometry analysis of cerulenin-reacted synthetic peptides derived from ketosynthase domains of A. carterae multimodular PKS transcripts demonstrated a strong covalent bond that could be localized using collision-induced dissociation. One multi-modular PKS sequence present in all dinoflagellates surveyed to date was found to lack an AT domain in toxin-producing species, indicating trans-acting domains, and was shown by Western blotting to be post-transcriptionally processed. These results demonstrate how toxin synthesis in dinoflagellates can be differentiated from fat synthesis despite common underlying pathway.
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Affiliation(s)
- Saddef Haq
- Institute for Marine and Environmental Technologies, University of Maryland Center for Environmental Science, 701 East Pratt St., Baltimore, MD 21202, USA; (S.H.); (E.W.); (T.B.)
| | - Benjamin L. Oyler
- University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, MD 21201, USA; (B.L.O.); (M.M.K.)
| | - Ernest Williams
- Institute for Marine and Environmental Technologies, University of Maryland Center for Environmental Science, 701 East Pratt St., Baltimore, MD 21202, USA; (S.H.); (E.W.); (T.B.)
| | - Mohd M. Khan
- University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, MD 21201, USA; (B.L.O.); (M.M.K.)
| | - David R. Goodlett
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8S 1P7, Canada;
| | - Tsvetan Bachvaroff
- Institute for Marine and Environmental Technologies, University of Maryland Center for Environmental Science, 701 East Pratt St., Baltimore, MD 21202, USA; (S.H.); (E.W.); (T.B.)
| | - Allen R. Place
- Institute for Marine and Environmental Technologies, University of Maryland Center for Environmental Science, 701 East Pratt St., Baltimore, MD 21202, USA; (S.H.); (E.W.); (T.B.)
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3
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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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Vinnik V, Zhang F, Park H, Cook TB, Throckmorton K, Pfleger BF, Bugni TS, Thomas MG. Structural and Biosynthetic Analysis of the Fabrubactins, Unusual Siderophores from Agrobacterium fabrum Strain C58. ACS Chem Biol 2021; 16:125-135. [PMID: 33373180 DOI: 10.1021/acschembio.0c00809] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Siderophores are iron-chelating molecules produced by microorganisms and plants to acquire exogenous iron. Siderophore biosynthetic enzymology often produces elaborate and unique molecules through unusual reactions to enable specific recognition by the producing organisms. Herein, we report the structure of two siderophore analogs from Agrobacterium fabrum strain C58, which we named fabrubactin (FBN) A and FBN B. Additionally, we characterized the substrate specificities of the NRPS and PKS components. The structures suggest unique Favorskii-like rearrangements of the molecular backbone that we propose are catalyzed by the flavin-dependent monooxygenase, FbnE. FBN A and B contain a 1,1-dimethyl-3-amino-1,2,3,4-tetrahydro-7,8-dihydroxy-quinolin (Dmaq) moiety previously seen only in the anachelin cyanobacterial siderophores. We provide evidence that Dmaq is derived from l-DOPA and propose a mechanism for the formation of the mature Dmaq moiety. Our bioinformatic analyses suggest that FBN A and B and the anachelins belong to a large and diverse siderophore family widespread throughout the Rhizobium/Agrobacterium group, α-proteobacteria, and cyanobacteria.
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Affiliation(s)
- Vladimir Vinnik
- Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Fan Zhang
- Pharmaceutical Sciences Division, University of Wisconsin—Madison, Madison, Wisconsin 53705, United States
| | - Hyunjun Park
- Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
- CATALOG, Boston, Massachusetts 02129, United States
| | - Taylor B. Cook
- Department of Chemical and Biological Engineering, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Kurt Throckmorton
- Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Brian F. Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Tim S. Bugni
- Pharmaceutical Sciences Division, University of Wisconsin—Madison, Madison, Wisconsin 53705, United States
| | - Michael G. Thomas
- Department of Bacteriology, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
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5
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Ismail FMD, Nahar L, Sarker SD. Application of INADEQUATE NMR techniques for directly tracing out the carbon skeleton of a natural product. PHYTOCHEMICAL ANALYSIS : PCA 2021; 32:7-23. [PMID: 32671944 DOI: 10.1002/pca.2976] [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] [Received: 06/14/2020] [Revised: 06/25/2020] [Accepted: 06/26/2020] [Indexed: 06/11/2023]
Abstract
INTRODUCTION Nuclear magnetic resonance (NMR) measurement of 1 JCC coupling by two-dimensional (2D) INADEQUATE (incredible natural abundance double quantum transfer experiment), which is a special case of double-quantum (DQ) spectroscopy that offers unambiguous determination of 13 C-13 C spin-spin connectivities through the DQ transitions of the spin system, is especially suited to solving structures rich in quaternary carbons and poor in hydrogen content (Crews rule). OBJECTIVE To review published literature on the application of NMR methods to determine structure in the liquid-state, which specifically considers the interaction of a pair of carbon-13 (13 C) nuclei adjacent to one another, to allow direct tracing out of contiguous carbon connectivity using 2D INADEQUATE. METHODOLOGY A comprehensive literature search was implemented with various databases: Web of Knowledge, PubMed and SciFinder, and other relevant published materials including published monographs. The keywords used, in various combinations, with INADEQUATE being present in all combinations, in the search were 2D NMR, 1 JCC coupling, natural product, structure elucidation, 13 C-13 C connectivity, cryoprobe and CASE (computer-assisted structure elucidation)/PANACEA (protons and nitrogen and carbon et alia). RESULTS The 2D INADEQUATE continues to solve "intractable" problems in natural product chemistry, and using milligram quantities with cryoprobe techniques combined with CASE/PANACEA experiments can increase machine time efficiency. The 13 C-13 C-based structural elucidation by dissolution single-scan dynamic nuclear polarisation NMR can overcome disadvantages of 13 C insensitivity at natural abundance. Selected examples have demonstrated the trajectory of INADEQUATE spectroscopy from structural determination to clarification of metabolomics analysis and use of DFT (density functional theory) and coupling constants to clarify the connectivity, hybridisation and stereochemistry within natural products. CONCLUSIONS Somewhat neglected over the years because of perceived lack of sensitivity, the 2D INADEQUATE NMR technique has re-emerged as a useful tool for solving natural products structures, which are rich in quaternary carbons and poor in hydrogen content.
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Affiliation(s)
- Fyaz M D Ismail
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, Merseyside, L3 3AF, UK
| | - Lutfun Nahar
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, Merseyside, L3 3AF, UK
- Laboratory of Growth Regulators, Institute of Experimental Botany ASCR & Palacký University, Olomouc, Czech Republic
| | - Satyajit D Sarker
- Centre for Natural Products Discovery, School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool, Merseyside, L3 3AF, UK
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6
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Biosynthesis of marine toxins. Curr Opin Chem Biol 2020; 59:119-129. [DOI: 10.1016/j.cbpa.2020.06.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/21/2020] [Accepted: 06/23/2020] [Indexed: 12/18/2022]
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Van Dolah FM, Morey JS, Milne S, Ung A, Anderson PE, Chinain M. Transcriptomic analysis of polyketide synthases in a highly ciguatoxic dinoflagellate, Gambierdiscus polynesiensis and low toxicity Gambierdiscus pacificus, from French Polynesia. PLoS One 2020; 15:e0231400. [PMID: 32294110 PMCID: PMC7159223 DOI: 10.1371/journal.pone.0231400] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/23/2020] [Indexed: 11/18/2022] Open
Abstract
Marine dinoflagellates produce a diversity of polyketide toxins that are accumulated in marine food webs and are responsible for a variety of seafood poisonings. Reef-associated dinoflagellates of the genus Gambierdiscus produce toxins responsible for ciguatera poisoning (CP), which causes over 50,000 cases of illness annually worldwide. The biosynthetic machinery for dinoflagellate polyketides remains poorly understood. Recent transcriptomic and genomic sequencing projects have revealed the presence of Type I modular polyketide synthases in dinoflagellates, as well as a plethora of single domain transcripts with Type I sequence homology. The current transcriptome analysis compares polyketide synthase (PKS) gene transcripts expressed in two species of Gambierdiscus from French Polynesia: a highly toxic ciguatoxin producer, G. polynesiensis, versus a non-ciguatoxic species G. pacificus, each assembled from approximately 180 million Illumina 125 nt reads using Trinity, and compares their PKS content with previously published data from other Gambierdiscus species and more distantly related dinoflagellates. Both modular and single-domain PKS transcripts were present. Single domain β-ketoacyl synthase (KS) transcripts were highly amplified in both species (98 in G. polynesiensis, 99 in G. pacificus), with smaller numbers of standalone acyl transferase (AT), ketoacyl reductase (KR), dehydratase (DH), enoyl reductase (ER), and thioesterase (TE) domains. G. polynesiensis expressed both a larger number of multidomain PKSs, and larger numbers of modules per transcript, than the non-ciguatoxic G. pacificus. The largest PKS transcript in G. polynesiensis encoded a 10,516 aa, 7 module protein, predicted to synthesize part of the polyether backbone. Transcripts and gene models representing portions of this PKS are present in other species, suggesting that its function may be performed in those species by multiple interacting proteins. This study contributes to the building consensus that dinoflagellates utilize a combination of Type I modular and single domain PKS proteins, in an as yet undefined manner, to synthesize polyketides.
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Affiliation(s)
- Frances M. Van Dolah
- Marine Genomics Core, Hollings Marine Laboratory, Charleston, SC, United States of America
- * E-mail:
| | - Jeanine S. Morey
- Marine Genomics Core, Hollings Marine Laboratory, Charleston, SC, United States of America
| | - Shard Milne
- Charleston Computational Genomics Group, Department of Computer Science, College of Charleston, Charleston, SC, United States of America
| | - André Ung
- Laboratoire des Biotoxines Marines, Institut Louis Malardé—UMR 241 EIO, Papeete, Tahiti, French Polynesia
| | - Paul E. Anderson
- Charleston Computational Genomics Group, Department of Computer Science, College of Charleston, Charleston, SC, United States of America
| | - Mireille Chinain
- Laboratoire des Biotoxines Marines, Institut Louis Malardé—UMR 241 EIO, Papeete, Tahiti, French Polynesia
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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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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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Saito T. Reaction Development Utilizing the Features of Chemical Elements and Synthesis of Marine Natural Products. YAKUGAKU ZASSHI 2018; 138:1335-1344. [DOI: 10.1248/yakushi.18-00126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Tatsuo Saito
- Graduate School of Pharmaceutical Sciences, The University of Tokyo
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11
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Van Dolah FM, Kohli GS, Morey JS, Murray SA. Both modular and single-domain Type I polyketide synthases are expressed in the brevetoxin-producing dinoflagellate, Karenia brevis (Dinophyceae). JOURNAL OF PHYCOLOGY 2017; 53:1325-1339. [PMID: 28949419 PMCID: PMC5725682 DOI: 10.1111/jpy.12586] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 09/14/2017] [Indexed: 05/09/2023]
Abstract
Dinoflagellates are prolific producers of polyketide compounds, many of which are potent toxins with adverse impacts on human and marine animal health. To identify polyketide synthase (PKS) genes in the brevetoxin-producing dinoflagellate, Karenia brevis, we assembled a transcriptome from 595 million Illumina reads, sampled under different growth conditions. The assembly included 125,687 transcripts greater than 300 nt in length, with over half having >100× coverage. We found 121 transcripts encoding Type I ketosynthase (KS) domains, of which 99 encoded single KS domains, while 22 contained multiple KS domains arranged in 1-3 protein modules. Phylogenetic analysis placed all single domain and a majority of multidomain KSs within a monophyletic clade of protist PKSs. In contrast with the highly amplified single-domain KSs, only eight single-domain ketoreductase transcripts were found in the assembly, suggesting that they are more evolutionarily conserved. The multidomain PKSs were dominated by trans-acyltransferase architectures, which were recently shown to be prevalent in other algal protists. Karenia brevis also expressed several hybrid nonribosomal peptide synthetase (NRPS)/PKS sequences, including a burA-like sequence previously reported in a wide variety of dinoflagellates. This contrasts with a similarly deep transcriptome of Gambierdiscus polynesiensis, which lacked NRPS/PKS other than the burA-like transcript, and may reflect the presence of amide-containing polyketides in K. brevis and their absence from G. polynesiensis. In concert with other recent transcriptome analyses, this study provides evidence for both single domain and multidomain PKSs in the synthesis of polyketide compounds in dinoflagellates.
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Affiliation(s)
- Frances M. Van Dolah
- College of CharlestonSchool of Sciences and Mathematics66 George St.CharlestonSouth Carolina29424USA
- Hollings Marine Laboratory331 Fort Johnson Rd.CharlestonSouth Carolina29412USA
| | - Gurjeet S. Kohli
- Climate Change ClusterUniversity of Technology Sydney15 Broadway, UltimoSydneyNew South Wales2007Australia
- Singapore Centre for Environmental Life Sciences EngineeringNanyang Technological UniversitySingapore689528
| | - Jeanine S. Morey
- Hollings Marine Laboratory331 Fort Johnson Rd.CharlestonSouth Carolina29412USA
- JHT Incorporated2710 Discovery Dr.OrlandoFlorida32826USA
| | - Shauna A. Murray
- Climate Change ClusterUniversity of Technology Sydney15 Broadway, UltimoSydneyNew South Wales2007Australia
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12
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Kohli GS, Campbell K, John U, Smith KF, Fraga S, Rhodes LL, Murray SA. Role of Modular Polyketide Synthases in the Production of Polyether Ladder Compounds in Ciguatoxin-Producing Gambierdiscus polynesiensis and G. excentricus (Dinophyceae). J Eukaryot Microbiol 2017; 64:691-706. [PMID: 28211202 DOI: 10.1111/jeu.12405] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 01/31/2017] [Accepted: 02/03/2017] [Indexed: 11/28/2022]
Abstract
Gambierdiscus, a benthic dinoflagellate, produces ciguatoxins that cause the human illness Ciguatera. Ciguatoxins are polyether ladder compounds that have a polyketide origin, indicating that polyketide synthases (PKS) are involved in their production. We sequenced transcriptomes of Gambierdiscus excentricus and Gambierdiscus polynesiensis and found 264 contigs encoding single domain ketoacyl synthases (KS; G. excentricus: 106, G. polynesiensis: 143) and ketoreductases (KR; G. excentricus: 7, G. polynesiensis: 8) with sequence similarity to type I PKSs, as reported in other dinoflagellates. In addition, 24 contigs (G. excentricus: 3, G. polynesiensis: 21) encoding multiple PKS domains (forming typical type I PKSs modules) were found. The proposed structure produced by one of these megasynthases resembles a partial carbon backbone of a polyether ladder compound. Seventeen contigs encoding single domain KS, KR, s-malonyltransacylase, dehydratase and enoyl reductase with sequence similarity to type II fatty acid synthases (FAS) in plants were found. Type I PKS and type II FAS genes were distinguished based on the arrangement of domains on the contigs and their sequence similarity and phylogenetic clustering with known PKS/FAS genes in other organisms. This differentiation of PKS and FAS pathways in Gambierdiscus is important, as it will facilitate approaches to investigating toxin biosynthesis pathways in dinoflagellates.
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Affiliation(s)
- Gurjeet S Kohli
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 689528, Singapore
| | - Katrina Campbell
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast, BT9 5AG, United Kingdom
| | - Uwe John
- Alfred-Wegener-Institute Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, 27515, Germany.,Helmholtz Institute for Functional Marine Biodiversity, University of Oldenburg, Oldenburg, 26111, Germany
| | - Kirsty F Smith
- Cawthron Institute, 98 Halifax Street East, Nelson, 7010, New Zealand
| | - Santiago Fraga
- Instituto Español de Oceanografía, Centro Oceanográfico de Vigo, Subida a Radio Faro 50, Vigo, 36390, Spain
| | - Lesley L Rhodes
- Cawthron Institute, 98 Halifax Street East, Nelson, 7010, New Zealand
| | - Shauna A Murray
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia
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13
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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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14
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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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15
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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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16
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Heravi MM, Ahmadi T, Ghavidel M, Heidari B, Hamidi H. Recent applications of the hetero Diels–Alder reaction in the total synthesis of natural products. RSC Adv 2015. [DOI: 10.1039/c5ra17488k] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The synthetic utility and potential power of the Diels–Alder (D–A) reaction in organic chemistry is evident.
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Affiliation(s)
| | | | | | | | - Hoda Hamidi
- Department of Chemistry
- Alzahra University
- Tehran
- Iran
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17
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Minamida M, Kumagai K, Ulanova D, Akakabe M, Konishi Y, Tominaga A, Tanaka H, Tsuda M, Fukushi E, Kawabata J, Masuda A, Tsuda M. Amphirionin-4 with potent proliferation-promoting activity on bone marrow stromal cells from a marine dinoflagellate amphidinium species. Org Lett 2014; 16:4858-61. [PMID: 25188336 DOI: 10.1021/ol5023504] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A linear polyketide, amphirionin-4 (1), has been isolated from cultivated algal cells of the marine dinoflagellate Amphidinium species. The structure was elucidated on the basis of detailed analyses of 1D and 2D NMR data, and the absolute configurations of C-4 and C-8 were determined using the modified Mosher's method. Amphirionin-4 (1) exhibited extremely potent proliferation-promoting activity on murine bone marrow stromal ST-2 cells (950% promotion) at a concentration of 0.1 ng/mL.
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Affiliation(s)
- Mika Minamida
- Department of Applied Science and ‡Center for Advanced Marine Core Research, Kochi University , Kochi 783-8502, Japan
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18
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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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19
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Calabro K, Guigonis JM, Teyssié JL, Oberhänsli F, Goudour JP, Warnau M, Bottein MYD, Thomas OP. Further insights into brevetoxin metabolism by de novo radiolabeling. Toxins (Basel) 2014; 6:1785-98. [PMID: 24918358 PMCID: PMC4073129 DOI: 10.3390/toxins6061785] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 05/23/2014] [Accepted: 05/27/2014] [Indexed: 11/16/2022] Open
Abstract
The toxic dinoflagellate Karenia brevis, responsible for early harmful algal blooms in the Gulf of Mexico, produces many secondary metabolites, including potent neurotoxins called brevetoxins (PbTx). These compounds have been identified as toxic agents for humans, and they are also responsible for the deaths of several marine organisms. The overall biosynthesis of these highly complex metabolites has not been fully ascertained, even if there is little doubt on a polyketide origin. In addition to gaining some insights into the metabolic events involved in the biosynthesis of these compounds, feeding studies with labeled precursors helps to discriminate between the de novo biosynthesis of toxins and conversion of stored intermediates into final toxic products in the response to environmental stresses. In this context, the use of radiolabeled precursors is well suited as it allows working with the highest sensitive techniques and consequently with a minor amount of cultured dinoflagellates. We were then able to incorporate [U-¹⁴C]-acetate, the renowned precursor of the polyketide pathway, in several PbTx produced by K. brevis. The specific activities of PbTx-1, -2, -3, and -7, identified by High-Resolution Electrospray Ionization Mass Spectrometer (HRESIMS), were assessed by HPLC-UV and highly sensitive Radio-TLC counting. We demonstrated that working at close to natural concentrations of acetate is a requirement for biosynthetic studies, highlighting the importance of highly sensitive radiolabeling feeding experiments. Quantification of the specific activity of the four, targeted toxins led us to propose that PbTx-1 and PbTx-2 aldehydes originate from oxidation of the primary alcohols of PbTx-7 and PbTx-3, respectively. This approach will open the way for a better comprehension of the metabolic pathways leading to PbTx but also to a better understanding of their regulation by environmental factors.
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Affiliation(s)
- Kevin Calabro
- Institut de Chimie de Nice-PCRE (Processus Chimiques et Radiochimiques dans l'Environnement), UMR 7272 CNRS, Université de Nice Sophia-Antipolis, Faculté des Sciences, Parc Valrose Nice 06108, France.
| | - Jean-Marie Guigonis
- Plateforme "Bernard Rossi"-Laboratoire TIRO (Transporteur en Imagerie Radiothérapie et Oncologie), UMR E 4320 CEA /iBEB /SBTN-CAL, Université de Nice Sophia Antipolis, Faculté de Médecine, 28 Avenue de Valombrose, Nice 06107, France.
| | - Jean-Louis Teyssié
- Radioecology Laboratory, International Atomic Energy Agency-Environment Laboratories, MC 98012, Monaco.
| | - François Oberhänsli
- Radioecology Laboratory, International Atomic Energy Agency-Environment Laboratories, MC 98012, Monaco.
| | - Jean-Pierre Goudour
- Geoazur Laboratory, Université de Nice-Sophia-Antipolis, UMR 7329 CNRS, UR 082 IRD, Campus Azur CNRS Bât. 1, 250 rue Albert Einstein, Sophia Antipolis Valbonne 06560, France.
| | - Michel Warnau
- Radioecology Laboratory, International Atomic Energy Agency-Environment Laboratories, MC 98012, Monaco.
| | | | - Olivier P Thomas
- Institut de Chimie de Nice-PCRE (Processus Chimiques et Radiochimiques dans l'Environnement), UMR 7272 CNRS, Université de Nice Sophia-Antipolis, Faculté des Sciences, Parc Valrose Nice 06108, France.
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20
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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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21
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Yamazaki M, Izumikawa M, Tachibana K, Satake M, Itoh Y, Hashimoto M. Origins of Oxygen Atoms in a Marine Ladder-Frame Polyether: Evidence of Monooxygenation by 18O-Labeling and Using Tandem Mass Spectrometry. J Org Chem 2012; 77:4902-6. [DOI: 10.1021/jo300531t] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Masatoshi Yamazaki
- Department of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Miho Izumikawa
- Department of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kazuo Tachibana
- Department of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masayuki Satake
- Department of Chemistry, School
of Science, The University of Tokyo, 7-3-1
Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yoshiyuki Itoh
- MS Business Unit, JEOL Ltd., 3-12 Musashino, Akishima, Tokyo 196-8558,
Japan
| | - Masahiro Hashimoto
- MS Business Unit, JEOL Ltd., 3-12 Musashino, Akishima, Tokyo 196-8558,
Japan
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22
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Yamazaki M, Tachibana K, Satake M. Complete 13C-labeling pattern of yessotoxin a marine ladder-frame polyether. Tetrahedron 2011. [DOI: 10.1016/j.tet.2010.12.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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23
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Fuwa H. Total Synthesis of Structurally Complex Marine Oxacyclic Natural Products. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2010. [DOI: 10.1246/bcsj.20100209] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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24
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Alvarez E, Díaz MT, Zurita D, Zárraga M, Martín JD. Model Studies Directed Towards Microalga Polyether Toxins. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bscb.19900990904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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25
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Heffron TP, Simpson GL, Merino E, Jamison TF. Ladder polyether synthesis via epoxide-opening cascades directed by a disappearing trimethylsilyl group. J Org Chem 2010; 75:2681-701. [PMID: 20302314 PMCID: PMC3018858 DOI: 10.1021/jo1002455] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Epoxide-opening cascades offer the potential to construct complex polyether natural products expeditiously and in a manner that emulates the biogenesis proposed for these compounds. Herein we provide a full account of our development of a strategy that addresses several important challenges of such cascades. The centerpiece of the method is a trimethylsilyl (SiMe(3)) group that serves several purposes and leaves no trace of itself by the time the cascade has come to an end. The main function of the SiMe(3) group is to dictate the regioselectivity of epoxide opening. This strategy is the only general method of effecting endo-selective cascades under basic conditions.
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Affiliation(s)
| | - Graham L. Simpson
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Estibaliz Merino
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Timothy F. Jamison
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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26
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Vilotijevic I, Jamison TF. Synthesis of marine polycyclic polyethers via endo-selective epoxide-opening cascades. Mar Drugs 2010; 8:763-809. [PMID: 20411125 PMCID: PMC2857356 DOI: 10.3390/md8030763] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Revised: 03/11/2010] [Accepted: 03/18/2010] [Indexed: 11/17/2022] Open
Abstract
The proposed biosynthetic pathways to ladder polyethers of polyketide origin and oxasqualenoids of terpenoid origin share a dramatic epoxide-opening cascade as a key step. Polycyclic structures generated in these biosynthetic pathways display biological effects ranging from potentially therapeutic properties to extreme lethality. Much of the structural complexity of ladder polyether and oxasqualenoid natural products can be traced to these hypothesized cascades. In this review we summarize how such epoxide-opening cascade reactions have been used in the synthesis of ladder polyethers and oxasqualenoid natural products.
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Affiliation(s)
- Ivan Vilotijevic
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; E-Mail:
(I.V.)
| | - Timothy F. Jamison
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; E-Mail:
(I.V.)
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27
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Di Micco S, Chini MG, Riccio R, Bifulco G. Quantum Mechanical Calculation of NMR Parameters in the Stereostructural Determination of Natural Products. European J Org Chem 2010. [DOI: 10.1002/ejoc.200901255] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Simone Di Micco
- Department of Pharmaceutical Science, University of Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy, Fax: +39‐089969602
| | - Maria Giovanna Chini
- Department of Pharmaceutical Science, University of Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy, Fax: +39‐089969602
| | - Raffaele Riccio
- Department of Pharmaceutical Science, University of Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy, Fax: +39‐089969602
| | - Giuseppe Bifulco
- Department of Pharmaceutical Science, University of Salerno, via Ponte don Melillo, 84084 Fisciano (SA), Italy, Fax: +39‐089969602
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28
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Abstract
An enantioselective synthesis of marine alkaloid brevisamide was accomplished in a convergent manner. The synthesis utilized an enantioselective hetero-Diels-Alder reaction which sets three chiral centers in compound 11. The synthesis also features a modified Wolff-Kishner reduction, Rubottom oxidation, and Suzuki-Miyaura coupling to furnish brevisamide.
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Affiliation(s)
- Arun K Ghosh
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, USA.
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29
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Errera RM, Bourdelais A, Drennan MA, Dodd EB, Henrichs DW, Campbell L. Variation in brevetoxin and brevenal content among clonal cultures of Karenia brevis may influence bloom toxicity. Toxicon 2009; 55:195-203. [PMID: 19631681 DOI: 10.1016/j.toxicon.2009.07.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 07/14/2009] [Accepted: 07/16/2009] [Indexed: 10/20/2022]
Abstract
Karenia brevis, the major harmful algal (HA) species in the Gulf of Mexico, produces a suite of brevetoxins and brevenal, a nontoxic brevetoxin antagonist. K. brevis growth is reported to be optimum at oceanic conditions, yet blooms are most problematic in coastal waters. Differences in growth rate, total brevetoxin production, brevetoxin profiles and brevenal production were evaluated among eight K. brevis clones grown at salinities of 35 and 27, but otherwise identical conditions. All measured parameters varied significantly among clones and the individual responses to decreased salinity varied as well. At 27, growth rates of four clones increased (Wilson, TXB3, SP1 and SP2), but decreased in three others (TXB4, SP3 and NBK) as compared to 35. Total brevetoxin cellular concentration varied up to approximately ten-fold among clones. For most clones (5 of 8), no significant difference in total toxin production between salinity treatments was observed; however, there was a shift in brevetoxin profiles to a higher proportion of PbTx-1 vs. PbTx-2 (in 7 of 8 clones). Brevenal production decreased in the majority of the clones (6 of 8) when grown at a salinity of 27. Results suggest that K. brevis produces more PbTx-1 and less brevenal in lower salinity waters.
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Affiliation(s)
- Reagan M Errera
- Department of Oceanography, 3146 TAMU, Texas A&M University, College Station, TX 77843, USA
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30
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Vilotijevic I, Jamison T. Epoxidöffnungskaskaden zur Synthese polycyclischer Polyether-Naturstoffe. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200900600] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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31
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Satake M, Campbell A, Van Wagoner RM, Bourdelais AJ, Jacocks H, Baden DG, Wright JLC. Brevisin: an aberrant polycyclic ether structure from the dinoflagellate Karenia brevis and its implications for polyether assembly. J Org Chem 2009; 74:989-94. [PMID: 19123836 DOI: 10.1021/jo802183n] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Brevisin is an unprecedented polycyclic ether isolated from the dinoflagellate Karenia brevis, an organism well-known to produce complex polycyclic ethers. The structure of brevisin was determined by detailed analyses of MS and 2D NMR spectra and is remarkable in that it consists of two separate fused polyether ring assemblies linked by a methylene group. One of the polycyclic moieties contains a conjugated aldehyde side chain similar to that recently observed in other K. brevis metabolites, though the "interrupted" polyether structure of brevisin is novel and provides further insight into the biogenesis of such fused-ring polyether systems. On the basis of the unusual structure of brevisin, principles underlying the initiation of polyether assemblies are proposed. Brevisin was found to inhibit the binding of [(3)H]-PbTx-3 to its binding site on the voltage-sensitive sodium channels in rat brain synaptosomes.
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Affiliation(s)
- Masayuki Satake
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, USA
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32
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Vilotijevic I, Jamison TF. Epoxide-opening cascades in the synthesis of polycyclic polyether natural products. Angew Chem Int Ed Engl 2009; 48:5250-81. [PMID: 19572302 PMCID: PMC2810545 DOI: 10.1002/anie.200900600] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The structural features of polycyclic polyether natural products can, in some cases, be traced to their biosynthetic origin. However in case that are less well understood, only biosynthetic pathways that feature dramatic, yet speculative, epoxide-opening cascades are proposed. We summarize how such epoxide-opening cascade reactions have been used in the synthesis of polycyclic polyethers (see scheme) and related natural products.The group of polycyclic polyether natural products is of special interest owing to the fascinating structure and biological effects displayed by its members. The latter includes potentially therapeutic antibiotic, antifungal, and anticancer properties, and extreme lethality. The polycyclic structural features of this class of compounds can, in some cases, be traced to their biosynthetic origin, but in others that are less well understood, only to proposed biosynthetic pathways that feature dramatic, yet speculative, epoxide-opening cascades. In this review we summarize how such epoxide-opening cascade reactions have been used in the synthesis of polycyclic polyethers and related natural products.
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Affiliation(s)
- Ivan Vilotijevic
- Department of Chemistry, Massachusettes Institute of Technology, Cambridge, MA 02139 (USA), Fax: (+1) 617-324-0253, , , Homepage: http://web.mit.edu/chemistry/jamison
| | - Timothy F. Jamison
- Department of Chemistry, Massachusettes Institute of Technology, Cambridge, MA 02139 (USA), Fax: (+1) 617-324-0253, , , Homepage: http://web.mit.edu/chemistry/jamison
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Satake M, Bourdelais AJ, Van Wagoner RM, Baden DG, Wright JLC. Brevisamide: an unprecedented monocyclic ether alkaloid from the dinoflagellate Karenia brevis that provides a potential model for ladder-frame initiation. Org Lett 2008; 10:3465-8. [PMID: 18646771 DOI: 10.1021/ol801243n] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dinoflagellate Karenia brevis is known for the production of brevetoxins, a family of polycyclic ether toxins, as well as their antagonist brevenal. Further examination of organic extracts of K. brevis has uncovered yet another unprecedented cyclic ether alkaloid named brevisamide. This report describes the structure elucidation of brevisamide based on detailed MS and NMR spectral analysis, and the importance of this new compound in shedding light on the biogenesis of fused polyethers is discussed.
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Affiliation(s)
- Masayuki Satake
- Center for Marine Science, University of North Carolina, Wilmington, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409, USA
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34
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The toxic dinoflagellate Karenia brevis encodes novel type I-like polyketide synthases containing discrete catalytic domains. Protist 2008; 159:471-82. [PMID: 18467171 DOI: 10.1016/j.protis.2008.02.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2007] [Accepted: 02/08/2008] [Indexed: 11/22/2022]
Abstract
Karenia brevis is the Florida red tide dinoflagellate responsible for detrimental effects on human and environmental health through the production of brevetoxins. Brevetoxins are thought to be synthesized by a polyketide synthase (PKS) complex, but the gene cluster for this PKS has yet to be identified. Here, eight PKS transcripts were identified in K. brevis by high throughput cDNA library screening. Full length sequences were obtained through 3' and 5' RACE, which demonstrated the presence of polyadenylation, 3'-UTRs, and an identical dinoflagellate-specific spliced leader sequence at the 5' end of PKS transcripts. Six transcripts encoded for individual ketosynthase (KS) domains, one ketoreductase (KR), and one transcript encoded both acyl carrier protein (ACP) and KS domains. Transcript lengths ranged from 1875 to 3397 nucleotides, based on sequence analysis, and were confirmed by northern blotting. Baysian phylogenetic analysis of the K. brevis KS domains placed them well within the protist type I PKS clade. Thus although most similar to type I modular PKSs, the presence of individual catalytic domains on separate transcripts suggests a protein structure more similar to type II PKSs, in which each catalytic domain resides on an individual protein. These results identify an unprecedented PKS structure in a toxic dinoflagellate.
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Michelliza S, Abraham WM, Jacocks HM, Schuster T, Baden DG. Synthesis, modeling, and biological evaluation of analogues of the semisynthetic brevetoxin antagonist beta-naphthoyl-brevetoxin. Chembiochem 2008; 8:2233-9. [PMID: 18000915 DOI: 10.1002/cbic.200700317] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Brevetoxins are neurotoxic compounds produced by the dinoflagellate Karenia brevis. Extensive blooms induce neurotoxic shellfish poisoning (NSP) and asthma-like symptoms in humans. beta-naphthoyl-brevetoxin, the first semisynthetic brevetoxin antagonist, has been defined as the lead compound in the investigation of the mechanisms of bronchoconstriction induced by inhaled brevetoxins and relaxation or reversal of those effects by selected derivatives. In pursuit of more potent and effective brevetoxin antagonists, a series of beta-naphthoyl-brevetoxin analogues have been synthesized. Activities were determined by competitive displacement of tritiated brevetoxin-3 from rat brain synaptosomes and by lung resistance measurements in sheep. Additionally, preliminary computational structural studies have been performed. All analogues bound to rat brain synaptosomes with affinities similar to beta-naphthoyl-brevetoxin but exhibited very different responses in sheep. The biological evaluations along with computational studies suggest that the brevetoxin binding site in rat brain synaptosome might be different from the ones in lung tissue and both steric and electrostatic factors contribute to the efficacy of brevetoxin antagonism.
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Affiliation(s)
- Sophie Michelliza
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin. K. Moss Lane, Wilmington, NC 28409, USA.
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Sasaki M, Fuwa H. Convergent strategies for the total synthesis of polycyclic ether marine metabolites. Nat Prod Rep 2008; 25:401-26. [PMID: 18389143 DOI: 10.1039/b705664h] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Marine polycyclic ether natural products continue to fascinate chemists and biologists due to their exceptionally large and complex molecular architectures and potent and diverse biological activities. Tremendous progress has been made over the past decade toward the total synthesis of marine polycyclic ether natural products. In this area, a convergent strategy for assembling small fragments into an entire molecule always plays a key role in successful total synthesis. This review describes our efforts to develop convergent strategies for the synthesis of polycyclic ethers and their application to the total synthesis of gambierol, gymnocin-A, and brevenal, and to the partial synthesis of the central part of ciguatoxins and the nonacyclic polyether skeleton of gambieric acids.
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Affiliation(s)
- Makoto Sasaki
- Laboratory of Biostructural Chemistry, Graduate School of Life Sciences, Tohoku University, 1-1 Tsutsumidori-amamiya, Aoba-ku, Sendai 981-8555, Japan.
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Oguri H. Bioorganic Studies Utilizing Rationally Designed Synthetic Molecules: Absolute Configuration of Ciguatoxin and Development of Immunoassay Systems. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.1870] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Rinehart KL. Secondary metabolites from marine organisms. CIBA FOUNDATION SYMPOSIUM 2007; 171:236-49; discussion 249-54. [PMID: 1302180 DOI: 10.1002/9780470514344.ch14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Marine macroorganisms and microorganisms, like terrestrial species, produce a dizzying array of secondary metabolites, including terpenes, steroids, polyketides, peptides, alkaloids and porphyrins. Most of the marine metabolites are found in terrestrial species as such or have close counterparts in land-based species, but some are sufficiently unusual to constitute a separate class (e.g. marine sterols). Although in many cases the functions of these secondary metabolites in the marine species themselves are unclear, other compounds play well-defined roles-for example as trail markers, sexual attractants, antifouling substances or antifeedants. What is clear is that many of the most interesting marine secondary metabolites have potent activities largely unrelated to their in situ roles. Examples abound of antitumour, antiviral, immunosuppressive and antimicrobial agents, as well as neurotoxins, hepatotoxins and cardiac stimulants. Relatively few biosynthetic studies of marine secondary metabolites have been done because of the logistical problems of working under water and the primitive state of techniques for growing marine invertebrates in culture. However, recent studies indicate that many compounds isolated from marine macrospecies (e.g. sponges) may instead be produced by microorganisms (e.g. bacteria or phytoplankton). Studies of these symbionts may facilitate efforts to understand the biosyntheses of these metabolites.
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Affiliation(s)
- K L Rinehart
- Roger Adams Laboratory, University of Illinois, Urbana 61801
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Abstract
Selectivity rules in organic chemistry have been inferred largely from nonaqueous environments. In contrast, enzymes operate in water, and the chemical effect of the medium change remains only partially understood. Structural characterization of the "ladder" polyether marine natural products raised a puzzle that persisted for 20 years: Although the stereochemistry of adjacent tetrahydropyran (THP) cycles would seem to arise from a biosynthetic cascade of epoxide-opening reactions, experience in organic solvents argued consistently that such a pathway would be kinetically disfavored. We report that neutral water acts as an optimal promoter for the requisite ring-opening selectivity, once a single templating THP is appended to a chain of epoxides. This strategy offers a high-yielding route to the naturally occurring ladder core and highlights the likely importance of aqueous-medium effects in underpinning certain noteworthy enzymatic selectivities.
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Affiliation(s)
- Ivan Vilotijevic
- Massachusetts Institute of Technology, Department of Chemistry, Cambridge, Massachusetts, 02139, USA
| | - Timothy F. Jamison
- Massachusetts Institute of Technology, Department of Chemistry, Cambridge, Massachusetts, 02139, USA
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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, CA 92037, USA.
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Fuwa H, Ebine M, Bourdelais AJ, Baden DG, Sasaki M. Total synthesis, structure revision, and absolute configuration of (-)-brevenal. J Am Chem Soc 2007; 128:16989-99. [PMID: 17177450 PMCID: PMC2575246 DOI: 10.1021/ja066772y] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Total synthesis of structure 1 originally proposed for brevenal, a nontoxic polycyclic ether natural product isolated from the Florida red tide dinoflagellate, Karenia brevis, was accomplished. The key features of the synthesis involved (i) convergent assembly of the pentacyclic polyether skeleton based on our developed Suzuki-Miyaura coupling chemistry and (ii) stereoselective construction of the multi-substituted (E,E)-dienal side chain by using copper(I) thiophen-2-carboxylate (CuTC)-promoted modified Stille coupling. The disparity of NMR spectra between the synthetic material and the natural product required a revision of the proposed structure. Detailed spectroscopic comparison of synthetic 1 with natural brevenal, coupled with the postulated biosynthetic pathway for marine polyether natural products, suggested that the natural product was most likely represented by 2, the C26 epimer of the proposed structure 1. The revised structure was finally validated by completing the first total synthesis of (-)-2, which also unambiguously established the absolute configuration of the natural product.
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Affiliation(s)
- Haruhiko Fuwa
- Laboratory of Biostructural Chemistry, Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai 981-8555, Japan
| | - Makoto Ebine
- Laboratory of Biostructural Chemistry, Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai 981-8555, Japan
| | - Andrea J. Bourdelais
- Wilmington Center for Marine Science, University of North Carolina, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
| | - Daniel G. Baden
- Wilmington Center for Marine Science, University of North Carolina, 5600 Marvin K. Moss Lane, Wilmington, North Carolina 28409
| | - Makoto Sasaki
- Laboratory of Biostructural Chemistry, Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai 981-8555, Japan
- E-mail:
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Abstract
The biomimetic synthesis of trans,syn,trans-fused polycyclic ether natural products involving a cascade of stereospecific and regioselective oxacyclizations of polyepoxide substrates is described as applied to the synthesis of polyoxepane and polypyran structures. In addition, an extension of biomimetic polyene cyclizations to terpenoid natural products is outlined.
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Clark JS. Construction of fused polycyclic ethers by strategies involving ring-closing metathesis. Chem Commun (Camb) 2006:3571-81. [PMID: 17047770 DOI: 10.1039/b601839d] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Large fused polycyclic ether natural products of marine origin are some of the most complex and formidable synthetic targets found in Nature, and they continue to fascinate and inspire those engaged in target-directed synthesis and the development of new synthetic methods. Novel strategies for the rapid and stereoselective assembly of fused polyethers have been devised in which ring-closing metathesis reactions are used to accomplish cyclic ether construction. Two-directional and iterative ring construction approaches involving ring-closing metathesis are being employed to assemble polyether sequences found in marine natural products such as the ciguatoxins and gambieric acids.
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Affiliation(s)
- J Stephen Clark
- School of Chemistry, University of Nottingham, University Park, Nottingham, UK NG7 2RD.
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Affiliation(s)
- Tadashi Nakata
- Department of Chemistry, Tokyo University of Science, Shinjuku-ku, Japan.
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Computer-aided determination of relative stereochemistry and 3D models of complex organic molecules from 2D NMR spectra. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.08.022] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Satoh H, Koshino H, Uno T, Koichi S, Iwata S, Nakata T. Effective consideration of ring structures in CAST/CNMR for highly accurate 13C NMR chemical shift prediction. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.05.074] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Snyder RV, Guerrero MA, Sinigalliano CD, Winshell J, Perez R, Lopez JV, Rein KS. Localization of polyketide synthase encoding genes to the toxic dinoflagellate Karenia brevis. PHYTOCHEMISTRY 2005; 66:1767-80. [PMID: 16051286 PMCID: PMC2573037 DOI: 10.1016/j.phytochem.2005.06.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Revised: 04/25/2005] [Indexed: 05/03/2023]
Abstract
Karenia brevis is a toxic marine dinoflagellate endemic to the Gulf of Mexico. Blooms of this harmful alga cause fish kills, marine mammal mortalities and neurotoxic shellfish poisonings. These harmful effects are attributed to a suite of polyketide secondary metabolites known as the brevetoxins. The carbon framework of all polyketides is assembled by a polyketide synthase (PKS). Previously, PKS encoding genes were amplified from K. brevis culture and their similarity to a PKS gene from the closely related protist, Cryptosporidium parvum, suggested that these genes originate from the dinoflagellate. However, K. brevis has not been grown axenically. The associated bacteria might be the source of the toxins or the PKS genes. Herein we report the localization of PKS encoding genes by a combination of flow cytometry/PCR and fluorescence in situ hybridization (FISH). Two genes localized exclusively to K. brevis cells while a third localized to both K. brevis and associated bacteria. While these genes have not yet been linked to toxin production, the work describes the first definitive evidence of resident PKS genes in any dinoflagellate.
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Affiliation(s)
- Richard V. Snyder
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th St., University Park, Miami, FL 33199, United States
| | - Maria A. Guerrero
- The Southeast Environmental Research Center, Florida International University, 11200 SW 8th St., Miami, FL 33199, United States
| | - Christopher D. Sinigalliano
- The Southeast Environmental Research Center, Florida International University, 11200 SW 8th St., Miami, FL 33199, United States
| | - Jamie Winshell
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th St., University Park, Miami, FL 33199, United States
| | - Roberto Perez
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th St., University Park, Miami, FL 33199, United States
| | - Jose V. Lopez
- Division of Biomedical Marine Research, Harbor Branch Oceanographic Institution, 5600 US 1 North, Ft. Pierce, FL 34946, United States
| | - Kathleen S. Rein
- Department of Chemistry and Biochemistry, Florida International University, 11200 SW 8th St., University Park, Miami, FL 33199, United States
- Corresponding author. Tel.: +1 305 348 6682; fax: +1 305 348 3772. E-mail address: (K.S. Rein)
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Oguri H, Oomura A, Tanabe S, Hirama M. Design and synthesis of a trans-fused polycyclic ether skeleton as an α-helix mimetic scaffold. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.02.039] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Fujiwara K, Murai A. Recent Advances in the Synthesis oftrans-Fused Polycyclic Ethers by Hydroxy-Epoxide-Cyclization and Ether-Ring-Expansion Reactions. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2004. [DOI: 10.1246/bcsj.77.2129] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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