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Tetrodotoxin Profiles in Xanthid Crab Atergatis floridus and Blue-Lined Octopus Hapalochlaena cf. fasciata from the Same Site in Nagasaki, Japan. Toxins (Basel) 2023; 15:toxins15030193. [PMID: 36977084 PMCID: PMC10052739 DOI: 10.3390/toxins15030193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
The xanhid crab Atergatis floridus and the blue-lined octopus Hapalochlaena cf. fasciata have long been known as TTX-bearing organisms. It has been speculated that the TTX possessed by both organisms is exogenously toxic through the food chain, since they are reported to have geographic and individual differences. The source and supply chain of TTX for both of these organisms, however, remain unclear. On the other hand, since crabs are one of the preferred prey of octopuses, we focused our attention on the relationship between the two species living in the same site. The aim of this study was to determine TTX concentrations and TTX profiles of A. floridus and H. cf. fasciata, collected simultaneously in the same site, and examine the relationship between them. Although there were individual differences in the TTX concentration in both A. floridus and H. cf. fasciata, the toxin components commonly contained 11-norTTX-6(S)-ol in addition to TTX as the major components, with 4-epiTTX, 11-deoxyTTX, and 4,9-anhydroTTX as the minor components. The results suggest that octopuses and crabs in this site acquire TTX from common prey, including TTX-producing bacteria and/or may have a predator–prey relationship.
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2
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Abstract
This review deals with the synthesis of naturally occurring alkaloids containing partially or completely saturated pyrimidine nuclei. The interest in these compounds is associated with their structural diversity, high biological activity and toxicity. The review is divided into four parts, each of which describes a number of synthetic methodologies toward structurally different naturally occurring alkaloids containing saturated cyclic six-membered amidine, guanidine, aminal and urea (thiourea) moieties, respectively. The development of various synthetic strategies for the preparation of these compounds has remarkably increased during the past few decades. This is primarily due to the fact that some of these compounds are isolated only in limited quantities, which makes it practically impossible to study their full structural characteristics and biological activity.
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3
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Tang DTY, Merit JE, Bedell TA, Du Bois J. Silylpyrrole Oxidation En Route to Saxitoxin Congeners Including 11-Saxitoxinethanoic Acid. J Org Chem 2021; 86:17790-17803. [PMID: 34874731 DOI: 10.1021/acs.joc.1c02116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Saxitoxin (STX) is the archetype of a large family (>50) of architecturally distinct, bisguanidinium natural products. Among this collection of isolates, two members, 11-saxitoxinethanoic acid (11-SEA) and zetekitoxin AB (ZTX), are unique, bearing carbon substitution at C11. A desire to efficiently access these compounds has motivated the development of new tactical approaches to a late-stage C11-ketone intermediate 26, designed to enable C-C bond formation using any one of a number of possible reaction technologies. Highlights of the synthesis of 26 include a metal-free, silylpyrrole oxidative dearomatization reaction and a vinylsilane epoxidation-rearrangement cascade to generate the requisite ketone. Nucleophilic addition to 26 makes possible the preparation of unnatural C11-substituted STXs. Olefination of this ketone is also demonstrated and, when followed by a redox-neutral isomerization reaction, affords 11-SEA.
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Affiliation(s)
- Doris T Y Tang
- Department of Chemistry, Stanford University, 333 Campus Dr., Stanford, California 94305, United States
| | - Jeffrey E Merit
- Department of Chemistry, Stanford University, 333 Campus Dr., Stanford, California 94305, United States
| | - T Aaron Bedell
- Department of Chemistry, Stanford University, 333 Campus Dr., Stanford, California 94305, United States
| | - J Du Bois
- Department of Chemistry, Stanford University, 333 Campus Dr., Stanford, California 94305, United States
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Berlinck RGS, Crnkovic CM, Gubiani JR, Bernardi DI, Ióca LP, Quintana-Bulla JI. The isolation of water-soluble natural products - challenges, strategies and perspectives. Nat Prod Rep 2021; 39:596-669. [PMID: 34647117 DOI: 10.1039/d1np00037c] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Covering period: up to 2019Water-soluble natural products constitute a relevant group of secondary metabolites notably known for presenting potent biological activities. Examples are aminoglycosides, β-lactam antibiotics, saponins of both terrestrial and marine origin, and marine toxins. Although extensively investigated in the past, particularly during the golden age of antibiotics, hydrophilic fractions have been less scrutinized during the last few decades. This review addresses the possible reasons on why water-soluble metabolites are now under investigated and describes approaches and strategies for the isolation of these natural compounds. It presents examples of several classes of hydrosoluble natural products and how they have been isolated. Novel stationary phases and chromatography techniques are also reviewed, providing a perspective towards a renaissance in the investigation of water-soluble natural products.
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Affiliation(s)
- Roberto G S Berlinck
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil.
| | - Camila M Crnkovic
- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, CEP 05508-000, São Paulo, SP, Brazil
| | - Juliana R Gubiani
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil.
| | - Darlon I Bernardi
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil.
| | - Laura P Ióca
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil.
| | - Jairo I Quintana-Bulla
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil.
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5
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Nagasawa K. Total Synthesis of Saxitoxins. J SYN ORG CHEM JPN 2021. [DOI: 10.5059/yukigoseikyokaishi.79.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Kazuo Nagasawa
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology
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6
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Okuyama Y, Okamoto R, Mukai S, Kinoshita K, Sato T, Chida N. Synthesis of Saxitoxin and Its Derivatives. Org Lett 2020; 22:8697-8701. [PMID: 33104353 DOI: 10.1021/acs.orglett.0c03281] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The chiral synthesis of (+)-saxitoxin and its derivatives is described. Two consecutive carbon-nitrogen bonds at C-5 and C-6 in saxitoxin were effectively installed by the sequential Overman rearrangement of an allylic vicinal diol derived from d-malic acid. The bicyclic guanidine unit was constructed by the intramolecular aminal formation of an acyclic bis-guanidine derivative possessing a ketone carbonyl at C-4. From the bicyclic aminal intermediate, (+)-saxitoxin, (+)-decarbamoyl-β-saxitoxinol [(+)-dc-β-saxitoxinol], and the unnatural skeletal isomer, (-)-iso-dc-saxitoxinol, were synthesized.
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Affiliation(s)
- Yuya Okuyama
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Ryosuke Okamoto
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Shori Mukai
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Kyoko Kinoshita
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Takaaki Sato
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Noritaka Chida
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
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7
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Berlinck RGS, Bernardi DI, Fill T, Fernandes AAG, Jurberg ID. The chemistry and biology of guanidine secondary metabolites. Nat Prod Rep 2020; 38:586-667. [PMID: 33021301 DOI: 10.1039/d0np00051e] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Covering: 2017-2019Guanidine natural products isolated from microorganisms, marine invertebrates and terrestrial plants, amphibians and spiders, represented by non-ribosomal peptides, guanidine-bearing polyketides, alkaloids, terpenoids and shikimic acid derived, are the subject of this review. The topics include the discovery of new metabolites, total synthesis of natural guanidine compounds, biological activity and mechanism-of-action, biosynthesis and ecological functions.
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Affiliation(s)
- Roberto G S Berlinck
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil.
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8
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Synthetic Approaches to Zetekitoxin AB, a Potent Voltage-Gated Sodium Channel Inhibitor. Mar Drugs 2019; 18:md18010024. [PMID: 31888062 PMCID: PMC7024329 DOI: 10.3390/md18010024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 12/23/2019] [Accepted: 12/24/2019] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated sodium channels (NaVs) are membrane proteins that are involved in the generation and propagation of action potentials in neurons. Recently, the structure of a complex made of a tetrodotoxin-sensitive (TTX-s) NaV subtype with saxitoxin (STX), a shellfish toxin, was determined. STX potently inhibits TTX-s NaV, and is used as a biological tool to investigate the function of NaVs. More than 50 analogs of STX have been isolated from nature. Among them, zetekitoxin AB (ZTX) has a distinctive chemical structure, and is the most potent inhibitor of NaVs, including tetrodotoxin-resistant (TTX-r) NaV. Despite intensive synthetic studies, total synthesis of ZTX has not yet been achieved. Here, we review recent efforts directed toward the total synthesis of ZTX, including syntheses of 11-saxitoxinethanoic acid (SEA), which is considered a useful synthetic model for ZTX, since it contains a key carbon-carbon bond at the C11 position.
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Paladugu SR, James CK, Looper RE. A Direct C11 Alkylation Strategy on the Saxitoxin Core: A Synthesis of (+)-11-Saxitoxinethanoic Acid. Org Lett 2019; 21:7999-8002. [DOI: 10.1021/acs.orglett.9b02986] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Srinivas R. Paladugu
- Department of Chemistry, University of Utah, 315 S 1400 E, Salt Lake City, Utah 84112, United States
| | - Chintelle K. James
- Department of Chemistry, University of Utah, 315 S 1400 E, Salt Lake City, Utah 84112, United States
| | - Ryan E. Looper
- Department of Chemistry, University of Utah, 315 S 1400 E, Salt Lake City, Utah 84112, United States
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10
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Walker JR, Merit JE, Thomas‐Tran R, Tang DTY, Du Bois J. Divergent Synthesis of Natural Derivatives of (+)‐Saxitoxin Including 11‐Saxitoxinethanoic Acid. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201811717] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
| | | | | | - Doris T. Y. Tang
- Department of ChemistryStanford University Stanford CA 94305 USA
| | - J. Du Bois
- Department of ChemistryStanford University Stanford CA 94305 USA
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11
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Walker JR, Merit JE, Thomas-Tran R, Tang DTY, Du Bois J. Divergent Synthesis of Natural Derivatives of (+)-Saxitoxin Including 11-Saxitoxinethanoic Acid. Angew Chem Int Ed Engl 2019; 58:1689-1693. [PMID: 30488599 DOI: 10.1002/anie.201811717] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Indexed: 11/06/2022]
Abstract
The bis-guanidinium toxins are a collection of natural products that display nanomolar potency against select isoforms of eukaryotic voltage-gated Na+ ion channels. We describe a synthetic strategy that enables access to four of these poisons, namely 11-saxitoxinethanoic acid, C13-acetoxy saxitoxin, decarbamoyl saxitoxin, and saxitoxin. Highlights of this work include an unusual Mislow-Evans rearrangement and a late-stage Stille ketene acetal coupling. The IC50 value of 11-saxitoxinethanoic acid was measured against rat NaV 1.4, and found to be 17.0 nm, similar to those of the sulfated toxins gonyautoxin II and III.
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Affiliation(s)
| | - Jeffrey E Merit
- Gilead Sciences, 333 Lakeside Dr., Foster City, CA, 94404, USA
| | | | - Doris T Y Tang
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - J Du Bois
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
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12
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Karagozlu MZ, Barbon MM, Dinh TD, Demayo CG, Kim CB. Complete mitochondrial genome of xanthid crab Atergatis floridus (Linnaeus, 1767). Mitochondrial DNA B Resour 2018; 3:202-204. [PMID: 33474118 PMCID: PMC7799886 DOI: 10.1080/23802359.2018.1437832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 02/01/2018] [Indexed: 11/01/2022] Open
Abstract
The complete mitochondrial genome sequenced from the floral egg crab Atergatis floridus (Linnaeus, 1767) and the determination of the position of the species in the reconstructed phylogenetic tree of the infraorder Brachyura using the protein coding mitochondrial genes are presented. Results show the mitochondrial genome length of A. floridus is 16,435 bp with nucleotide distribution as 33.4% A, 20.3% C, 10.5% G and 35.8% T. The structure of the complete mitochondrial genome of the species is the same as with the previous xanthid record. The result of the phylogenetic analysis suggests that A. floridus is the closest species to other Xanthidae species in the brachyuran records. This is the first complete mitochondrial genome record from the genus Atergatis.
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Affiliation(s)
| | - Michelle M. Barbon
- Department of Biological Sciences, College of Science and Mathematics, Mindanao State University, Iligan Institute of Technology, Iligan City, Philippines
| | - Thinh Do Dinh
- Department of Biotechnology, Sangmyung University, Seoul, Korea
| | - Cesar G. Demayo
- Department of Biological Sciences, College of Science and Mathematics, Mindanao State University, Iligan Institute of Technology, Iligan City, Philippines
| | - Chang-Bae Kim
- Department of Biotechnology, Sangmyung University, Seoul, Korea
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13
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Berlinck RGS, Bertonha AF, Takaki M, Rodriguez JPG. The chemistry and biology of guanidine natural products. Nat Prod Rep 2017; 34:1264-1301. [DOI: 10.1039/c7np00037e] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The chemistry and biology of natural guanidines isolated from microbial culture media, from marine invertebrates, as well as from terrestrial plants and animals, are reviewed.
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Affiliation(s)
| | - Ariane F. Bertonha
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
| | - Mirelle Takaki
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
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14
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Wang C, Oki M, Nishikawa T, Harada D, Yotsu-Yamashita M, Nagasawa K. Total Synthesis of 11-Saxitoxinethanoic Acid and Evaluation of its Inhibitory Activity on Voltage-Gated Sodium Channels. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201604155] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chao Wang
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
| | - Mana Oki
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
| | - Toru Nishikawa
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
| | - Daisuke Harada
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science; Tohoku University; 1-1 Tsutsumidori-Amamiya Aoba-ku Sendai 981-8555 Japan
| | - Kazuo Nagasawa
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
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15
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Wang C, Oki M, Nishikawa T, Harada D, Yotsu-Yamashita M, Nagasawa K. Total Synthesis of 11-Saxitoxinethanoic Acid and Evaluation of its Inhibitory Activity on Voltage-Gated Sodium Channels. Angew Chem Int Ed Engl 2016; 55:11600-3. [DOI: 10.1002/anie.201604155] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/17/2016] [Indexed: 11/05/2022]
Affiliation(s)
- Chao Wang
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
| | - Mana Oki
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
| | - Toru Nishikawa
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
| | - Daisuke Harada
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science; Tohoku University; 1-1 Tsutsumidori-Amamiya Aoba-ku Sendai 981-8555 Japan
| | - Kazuo Nagasawa
- Department of Biotechnology and Life Science, Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Nakamachi, Koganei Tokyo 184-8588 Japan
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Chau R, Kalaitzis JA, Neilan BA. On the origins and biosynthesis of tetrodotoxin. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2011; 104:61-72. [PMID: 21543051 DOI: 10.1016/j.aquatox.2011.04.001] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 03/30/2011] [Accepted: 04/01/2011] [Indexed: 05/30/2023]
Abstract
The potent neurotoxin tetrodotoxin (TTX) has been identified from taxonomically diverse marine organisms. TTX possesses a unique cage-like structure, however, its biosynthesis has yet to be elucidated. Biosynthetic studies in the TTX-producing newt Taricha torosa, and in bacterial genera, including Vibrio, have proven inconclusive. Indeed, very few studies have been performed that address the cellular production of TTX. Here we review the sources of TTX described to date and provide evidence for the biosynthesis of TTX by symbiotic microorganisms in higher taxa. Chemical and genetic based biosynthesis studies of TTX undertaken thus far are discussed and we outline approaches which may be useful for expanding upon the current body of knowledge. The complex biosynthesis of structurally similar toxins, that reveal clues into the biosynthetic pathway of TTX, is also presented.
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Affiliation(s)
- Rocky Chau
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
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17
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Mihali TK, Carmichael WW, Neilan BA. A putative gene cluster from a Lyngbya wollei bloom that encodes paralytic shellfish toxin biosynthesis. PLoS One 2011; 6:e14657. [PMID: 21347365 PMCID: PMC3037375 DOI: 10.1371/journal.pone.0014657] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Accepted: 01/10/2011] [Indexed: 11/19/2022] Open
Abstract
Saxitoxin and its analogs cause the paralytic shellfish-poisoning syndrome, adversely affecting human health and coastal shellfish industries worldwide. Here we report the isolation, sequencing, annotation, and predicted pathway of the saxitoxin biosynthetic gene cluster in the cyanobacterium Lyngbya wollei. The gene cluster spans 36 kb and encodes enzymes for the biosynthesis and export of the toxins. The Lyngbya wollei saxitoxin gene cluster differs from previously identified saxitoxin clusters as it contains genes that are unique to this cluster, whereby the carbamoyltransferase is truncated and replaced by an acyltransferase, explaining the unique toxin profile presented by Lyngbya wollei. These findings will enable the creation of toxin probes, for water monitoring purposes, as well as proof-of-concept for the combinatorial biosynthesis of these natural occurring alkaloids for the production of novel, biologically active compounds.
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Affiliation(s)
- Troco K. Mihali
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
| | - Wayne W. Carmichael
- Department of Biological Sciences, Wright State University, Dayton, Ohio, United States of America
| | - Brett A. Neilan
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
- Australian Centre for Astrobiology, The University of New South Wales, Sydney, Australia
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18
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Castberg T, Torgersen T, Aasen J, Aune T, Naustvoll LJ. Diarrhoetic shellfish poisoning toxins in Cancer pagurus Linnaeus, 1758 (Brachyura, Cancridae) in Norwegian waters. ACTA ACUST UNITED AC 2010. [DOI: 10.1080/00364820410002550] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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19
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Development of quantitative NMR method with internal standard for the standard solutions of paralytic shellfish toxins and characterisation of gonyautoxin-5 and gonyautoxin-6. Toxicon 2010; 56:589-95. [DOI: 10.1016/j.toxicon.2010.06.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Revised: 06/01/2010] [Accepted: 06/01/2010] [Indexed: 11/21/2022]
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20
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Wiese M, D’Agostino PM, Mihali TK, Moffitt MC, Neilan BA. Neurotoxic alkaloids: saxitoxin and its analogs. Mar Drugs 2010; 8:2185-211. [PMID: 20714432 PMCID: PMC2920551 DOI: 10.3390/md8072185] [Citation(s) in RCA: 421] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 07/12/2010] [Accepted: 07/16/2010] [Indexed: 11/25/2022] Open
Abstract
Saxitoxin (STX) and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs). PSTs are the causative agents of paralytic shellfish poisoning (PSP) and are mostly associated with marine dinoflagellates (eukaryotes) and freshwater cyanobacteria (prokaryotes), which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs--each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids.
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Affiliation(s)
- Maria Wiese
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia; E-Mails: (M.W.); (T.K.M.)
| | - Paul M. D’Agostino
- School of Biomedical and Health Sciences, University of Western Sydney, Campbelltown, NSW, 2560, Australia; E-Mails: (P.M.D.); (M.C.M.)
| | - Troco K. Mihali
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia; E-Mails: (M.W.); (T.K.M.)
| | - Michelle C. Moffitt
- School of Biomedical and Health Sciences, University of Western Sydney, Campbelltown, NSW, 2560, Australia; E-Mails: (P.M.D.); (M.C.M.)
| | - Brett A. Neilan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia; E-Mails: (M.W.); (T.K.M.)
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Pearson L, Mihali T, Moffitt M, Kellmann R, Neilan B. On the chemistry, toxicology and genetics of the cyanobacterial toxins, microcystin, nodularin, saxitoxin and cylindrospermopsin. Mar Drugs 2010; 8:1650-80. [PMID: 20559491 PMCID: PMC2885083 DOI: 10.3390/md8051650] [Citation(s) in RCA: 393] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Revised: 05/02/2010] [Accepted: 05/06/2010] [Indexed: 11/16/2022] Open
Abstract
The cyanobacteria or "blue-green algae", as they are commonly termed, comprise a diverse group of oxygenic photosynthetic bacteria that inhabit a wide range of aquatic and terrestrial environments, and display incredible morphological diversity. Many aquatic, bloom-forming species of cyanobacteria are capable of producing biologically active secondary metabolites, which are highly toxic to humans and other animals. From a toxicological viewpoint, the cyanotoxins span four major classes: the neurotoxins, hepatotoxins, cytotoxins, and dermatoxins (irritant toxins). However, structurally they are quite diverse. Over the past decade, the biosynthesis pathways of the four major cyanotoxins: microcystin, nodularin, saxitoxin and cylindrospermopsin, have been genetically and biochemically elucidated. This review provides an overview of these biosynthesis pathways and additionally summarizes the chemistry and toxicology of these remarkable secondary metabolites.
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Affiliation(s)
- Leanne Pearson
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia; E-Mails:
(L.P.);
(T.M.)
| | - Troco Mihali
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia; E-Mails:
(L.P.);
(T.M.)
| | - Michelle Moffitt
- School of Biomedical and Health Sciences, The University of Western Sydney, Campbelltown, NSW, 2560, Australia; E-Mail:
(M.M.)
| | - Ralf Kellmann
- Department of Molecular Biology, The University of Bergen, P.O. Box 7803, 5020 Bergen, Norway; E-Mail:
(R.K.)
| | - Brett Neilan
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia; E-Mails:
(L.P.);
(T.M.)
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Mihali TK, Kellmann R, Neilan BA. Characterisation of the paralytic shellfish toxin biosynthesis gene clusters in Anabaena circinalis AWQC131C and Aphanizomenon sp. NH-5. BMC BIOCHEMISTRY 2009; 10:8. [PMID: 19331657 PMCID: PMC2679770 DOI: 10.1186/1471-2091-10-8] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 03/30/2009] [Indexed: 11/10/2022]
Abstract
BACKGROUND Saxitoxin and its analogues collectively known as the paralytic shellfish toxins (PSTs) are neurotoxic alkaloids and are the cause of the syndrome named paralytic shellfish poisoning. PSTs are produced by a unique biosynthetic pathway, which involves reactions that are rare in microbial metabolic pathways. Nevertheless, distantly related organisms such as dinoflagellates and cyanobacteria appear to produce these toxins using the same pathway. Hypothesised explanations for such an unusual phylogenetic distribution of this shared uncommon metabolic pathway, include a polyphyletic origin, an involvement of symbiotic bacteria, and horizontal gene transfer. RESULTS We describe the identification, annotation and bioinformatic characterisation of the putative paralytic shellfish toxin biosynthesis clusters in an Australian isolate of Anabaena circinalis and an American isolate of Aphanizomenon sp., both members of the Nostocales. These putative PST gene clusters span approximately 28 kb and contain genes coding for the biosynthesis and export of the toxin. A putative insertion/excision site in the Australian Anabaena circinalis AWQC131C was identified, and the organization and evolution of the gene clusters are discussed. A biosynthetic pathway leading to the formation of saxitoxin and its analogues in these organisms is proposed. CONCLUSION The PST biosynthesis gene cluster presents a mosaic structure, whereby genes have apparently transposed in segments of varying size, resulting in different gene arrangements in all three sxt clusters sequenced so far. The gene cluster organizational structure and sequence similarity seems to reflect the phylogeny of the producer organisms, indicating that the gene clusters have an ancient origin, or that their lateral transfer was also an ancient event. The knowledge we gain from the characterisation of the PST biosynthesis gene clusters, including the identity and sequence of the genes involved in the biosynthesis, may also afford the identification of these gene clusters in dinoflagellates, the cause of human mortalities and significant financial loss to the tourism and shellfish industries.
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Affiliation(s)
- Troco K Mihali
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Ralf Kellmann
- Department of Molecular Biology, University of Bergen, P.O. Box 7803, 5020 Bergen, Norway
| | - Brett A Neilan
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
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Llewellyn LE. Sodium channel inhibiting marine toxins. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2009; 46:67-97. [PMID: 19184585 DOI: 10.1007/978-3-540-87895-7_3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Saxitoxin (STX), tetrodotoxin (TTX) and their many chemical relatives are part of our daily lives. From killing people who eat seafood containing these toxins, to being valuable research tools unveiling the invisible structures of their pharmacological receptor, their global impact is beyond measure. The pharmacological receptor for these toxins is the voltage-gated sodium channel which transports Na ions between the exterior to the interior of cells. The two structurally divergent families of STX and TTX analogues bind at the same location on these Na channels to stop the flow of ions. This can affect nerves, muscles and biological senses of most animals. It is through these and other toxins that we have developed much of our fundamental understanding of the Na channel and its part in generating action potentials in excitable cells.
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Affiliation(s)
- Lyndon E Llewellyn
- Australian Institute of Marine Science, Townsville MC, QLD 4810, Australia.
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Non-traditional vectors for paralytic shellfish poisoning. Mar Drugs 2008; 6:308-48. [PMID: 18728730 PMCID: PMC2525492 DOI: 10.3390/md20080015] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 06/03/2008] [Accepted: 06/03/2008] [Indexed: 11/28/2022] Open
Abstract
Paralytic shellfish poisoning (PSP), due to saxitoxin and related compounds, typically results from the consumption of filter-feeding molluscan shellfish that concentrate toxins from marine dinoflagellates. In addition to these microalgal sources, saxitoxin and related compounds, referred to in this review as STXs, are also produced in freshwater cyanobacteria and have been associated with calcareous red macroalgae. STXs are transferred and bioaccumulate throughout aquatic food webs, and can be vectored to terrestrial biota, including humans. Fisheries closures and human intoxications due to STXs have been documented in several non-traditional (i.e. non-filter-feeding) vectors. These include, but are not limited to, marine gastropods, both carnivorous and grazing, crustacea, and fish that acquire STXs through toxin transfer. Often due to spatial, temporal, or a species disconnection from the primary source of STXs (bloom forming dinoflagellates), monitoring and management of such non-traditional PSP vectors has been challenging. A brief literature review is provided for filter feeding (traditional) and non-filter feeding (non-traditional) vectors of STXs with specific reference to human effects. We include several case studies pertaining to management actions to prevent PSP, as well as food poisoning incidents from STX(s) accumulation in non-traditional PSP vectors.
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Biosynthetic intermediate analysis and functional homology reveal a saxitoxin gene cluster in cyanobacteria. Appl Environ Microbiol 2008; 74:4044-53. [PMID: 18487408 DOI: 10.1128/aem.00353-08] [Citation(s) in RCA: 233] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Saxitoxin (STX) and its analogues cause the paralytic shellfish poisoning (PSP) syndrome, which afflicts human health and impacts coastal shellfish economies worldwide. PSP toxins are unique alkaloids, being produced by both prokaryotes and eukaryotes. Here we describe a candidate PSP toxin biosynthesis gene cluster (sxt) from Cylindrospermopsis raciborskii T3. The saxitoxin biosynthetic pathway is encoded by more than 35 kb, and comparative sequence analysis assigns 30 catalytic functions to 26 proteins. STX biosynthesis is initiated with arginine, S-adenosylmethionine, and acetate by a new type of polyketide synthase, which can putatively perform a methylation of acetate, and a Claisen condensation reaction between propionate and arginine. Further steps involve enzymes catalyzing three heterocyclizations and various tailoring reactions that result in the numerous isoforms of saxitoxin. In the absence of a gene transfer system in these microorganisms, we have revised the description of the known STX biosynthetic pathway, with in silico functional inferences based on sxt open reading frames combined with liquid chromatography-tandem mass spectrometry analysis of the biosynthetic intermediates. Our results indicate the evolutionary origin for the production of PSP toxins in an ancestral cyanobacterium with genetic contributions from diverse phylogenetic lineages of bacteria and provide a quantum addition to the catalytic collective available for future combinatorial biosyntheses. The distribution of these genes also supports the idea of the involvement of this gene cluster in STX production in various cyanobacteria.
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Llewellyn LE. Predictive toxinology: an initial foray using calculated molecular descriptors to describe toxicity using saxitoxins as a model. Toxicon 2007; 50:901-13. [PMID: 17675202 DOI: 10.1016/j.toxicon.2007.06.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 06/20/2007] [Accepted: 06/21/2007] [Indexed: 11/30/2022]
Abstract
Molecular descriptors and their mathematical combination have been used for predictive toxicology and risk assessments of environmental pollutants and pharmaceutical leads. However, this approach has not yet been used for natural toxins and may contribute to health and environmental risk assessments of newly discovered toxins without having to undertake whole animal toxicology. To explore this approach, over 3000 descriptors were calculated for each of the 30 saxitoxins for which mouse toxicities have been reported. This dataset was reduced to only 87 descriptors by firstly eliminating descriptors that were the same for all toxins or could not be calculated for all 30 toxins, and then removing those descriptors that did not have a statistically significant linear relationship with toxicity values. From the remaining 87 descriptors, a subset of seven descriptors was identified upon which various mathematical approaches were assessed for their ability to fit the dataset both with and without leave-one-out cross-validation. K-nearest neighbours and support vector machine regression along with various combinations of these seven descriptors fit the toxicity data almost perfectly and also achieved high predictability as measured by leave-one-out cross-validation. Of these seven descriptors, five incorporated weighting by estimates of atomic polarizability and electronic states. Predicted toxicities of several saxitoxins of unknown toxicity bore similarities to the pattern of known potencies of these toxins on various isoforms of the voltage-gated sodium channel. Some of these predicted toxicity values however would not be expected if there was a direct relationship between mammalian sodium channel affinity of the saxitoxins and whole animal toxicity.
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Affiliation(s)
- Lyndon E Llewellyn
- Australian Institute of Marine Science, PMB 3, Townsville MC, Qld 4810, Australia.
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Llewellyn LE. Saxitoxin, a toxic marine natural product that targets a multitude of receptors. Nat Prod Rep 2006; 23:200-22. [PMID: 16572228 DOI: 10.1039/b501296c] [Citation(s) in RCA: 238] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Saxitoxin (STX) was discovered early last century and can contaminate seafood and drinking water, and over time has become an invaluable research tool and an internationally regulated chemical weapon. Among natural products, toxins obtain a unique reputation from their high affinity and selectivity for their target pharmacological receptor, which for STX has long been considered to only be the voltage gated sodium channel. In recent times however, STX has been discovered to also bind to calcium and potassium channels, neuronal nitric oxide synthase, STX metabolizing enzymes and two circulatory fluid proteins, namely a transferrin-like family of proteins and a unique protein found in the blood of pufferfish.
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Yotsu-Yamashita M, Kim YH, Dudley SC, Choudhary G, Pfahnl A, Oshima Y, Daly JW. The structure of zetekitoxin AB, a saxitoxin analog from the Panamanian golden frog Atelopus zeteki: a potent sodium-channel blocker. Proc Natl Acad Sci U S A 2004; 101:4346-51. [PMID: 15070720 PMCID: PMC384749 DOI: 10.1073/pnas.0400368101] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bufonid anurans of the genus Atelopus contain both steroidal bufadienolides and various guanidinium alkaloids of the tetrodotoxin class. The former inhibit sodium-potassium ATPases, whereas the latter block voltage-dependent sodium channels. The structure of one guanidinium alkaloid, zetekitoxin AB, has remained a mystery for over 30 years. The structure of this alkaloid now has been investigated with a sample of approximately 0.3 mg, purified from extracts obtained decades ago from the Panamanian golden frog Atelopus zeteki. Detailed NMR and mass spectral analyses have provided the structure and relative stereochemistry of zetekitoxin AB and have revealed that it is an analog of saxitoxin. The proposed structure is characterized by richness of heteroatoms (C16H25N8O12S) and contains a unique 1,2-oxazolidine ring-fused lactam, a sulfate ester, and an N-hydroxycarbamate moiety. Zetekitoxin AB proved to be an extremely potent blocker of voltage-dependent sodium channels expressed in Xenopus oocytes. The IC50 values were 280 pM for human heart channels, 6.1 pM for rat brain IIa channels, and 65 pM for rat skeletal muscle channels, thus being roughly 580-, 160-, and 63-fold more potent at these channels than saxitoxin.
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Affiliation(s)
- Mari Yotsu-Yamashita
- Graduate School of Agricultural Science, Tohoku University, Sendai 981-8555, Japan.
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Zaman L, Arakawa O, Shimosu A, Shida Y, Onoue Y. Occurrence of a methyl derivative of saxitoxin in Bangladeshi freshwater puffers. Toxicon 1998; 36:627-30. [PMID: 9643475 DOI: 10.1016/s0041-0101(97)00086-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A new component of paralytic shellfish poison was isolated from a Bangladeshi freshwater puffer Tetraodon cutcutia. Its structure was deduced to be carbamoyl-N-methylsaxitoxin based on electrospray ionization mass spectrometry, [1H] NMR, and conversion experiments.
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Affiliation(s)
- L Zaman
- Laboratory of Aquatic Resource Science, Faculty of Fisheries, Kagoshima University, Shimoarata, Japan
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Tsai YH, Hwang DF, Chai TJ, Jeng SS. Toxicity and toxic components of two xanthid crabs, Atergatis floridus and Demania reynaudi, in Taiwan. Toxicon 1997; 35:1327-35. [PMID: 9278980 DOI: 10.1016/s0041-0101(97)00005-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Paralytic toxicity was detected by tetrodotoxin bioassay in eight specimens of Atergatis floridus and seven specimens of Demania reynaudi, collected from Taiwan in 1994. The toxicity of crab specimens was 161 +/- 115 (mean +/- S.D.) mouse units (MU) for A. floridus and 640 +/- 273 MU for D. reynaudi. The respective toxins were partially purified from specimens of A. floridus and D. reynaudi by ultrafiltration using a Diaflo YM-1 membrane, followed by chromatography on a Bio-Gel P-2 column. Electrophoresis, thin-layer chromatography, high-performance liquid chromatography, ultraviolet spectrum and gas chromatography-mass spectrometry indicated that the toxin of A. floridus was mainly composed of tetrodotoxin (85%), along with minor gonyautoxin 1-4 (15%), and the toxin of D. reynaudi was mainly composed of tetrodotoxin (88%), along with minor gonyautoxin 2-4 and neosaxitoxin (12%).
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Affiliation(s)
- Y H Tsai
- Department of Marine Food Science, National Taiwan Ocean University, Keelung, R.O.C
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