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Mules TC, Tang JS, Vacca F, Yumnam B, Schmidt A, Lavender B, Maclean K, Noble SL, Waugh C, van Ginkel R, Camberis M, Le Gros G, Inns S. Modulation of intestinal epithelial permeability by chronic small intestinal helminth infections. Immunol Cell Biol 2024. [PMID: 38648862 DOI: 10.1111/imcb.12749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 03/18/2024] [Accepted: 03/28/2024] [Indexed: 04/25/2024]
Abstract
Increased permeability of the intestinal epithelial layer is linked to the pathogenesis and perpetuation of a wide range of intestinal and extra-intestinal diseases. Infecting humans with controlled doses of helminths, such as human hookworm (termed hookworm therapy), is proposed as a treatment for many of the same diseases. Helminths induce immunoregulatory changes in their host which could decrease epithelial permeability, which is highlighted as a potential mechanism through which helminths treat disease. Despite this, the influence of a chronic helminth infection on epithelial permeability remains unclear. This study uses the chronically infecting intestinal helminth Heligmosomoides polygyrus to reveal alterations in the expression of intestinal tight junction proteins and epithelial permeability during the infection course. In the acute infection phase (1 week postinfection), an increase in intestinal epithelial permeability is observed. Consistent with this finding, jejunal claudin-2 is upregulated and tricellulin is downregulated. By contrast, in the chronic infection phase (6 weeks postinfection), colonic claudin-1 is upregulated and epithelial permeability decreases. Importantly, this study also investigates changes in epithelial permeability in a small human cohort experimentally challenged with the human hookworm, Necator americanus. It demonstrates a trend toward small intestinal permeability increasing in the acute infection phase (8 weeks postinfection), and colonic and whole gut permeability decreasing in the chronic infection phase (24 weeks postinfection), suggesting a conserved epithelial response between humans and mice. In summary, our findings demonstrate dynamic changes in epithelial permeability during a chronic helminth infection and provide another plausible mechanism by which chronic helminth infections could be utilized to treat disease.
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Affiliation(s)
- Thomas C Mules
- Malaghan Institute of Medical Research, Wellington, New Zealand
- University of Otago, Wellington, New Zealand
| | - Jeffry S Tang
- Malaghan Institute of Medical Research, Wellington, New Zealand
- High-Value Nutrition National Science Challenge, Auckland, New Zealand
| | - Francesco Vacca
- Malaghan Institute of Medical Research, Wellington, New Zealand
| | - Bibek Yumnam
- Malaghan Institute of Medical Research, Wellington, New Zealand
| | - Alfonso Schmidt
- Malaghan Institute of Medical Research, Wellington, New Zealand
| | | | - Kate Maclean
- Malaghan Institute of Medical Research, Wellington, New Zealand
| | | | | | | | - Mali Camberis
- Malaghan Institute of Medical Research, Wellington, New Zealand
| | - Graham Le Gros
- Malaghan Institute of Medical Research, Wellington, New Zealand
| | - Stephen Inns
- Malaghan Institute of Medical Research, Wellington, New Zealand
- University of Otago, Wellington, New Zealand
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Murray JS, Finch SC, Mudge EM, Wilkins AL, Puddick J, Harwood DT, Rhodes LL, van Ginkel R, Rise F, Prinsep MR. Structural Characterization of Maitotoxins Produced by Toxic Gambierdiscus Species. Mar Drugs 2022; 20:md20070453. [PMID: 35877746 PMCID: PMC9324523 DOI: 10.3390/md20070453] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/08/2022] [Accepted: 07/10/2022] [Indexed: 01/27/2023] Open
Abstract
Identifying compounds responsible for the observed toxicity of the Gambierdiscus species is a critical step to ascertaining whether they contribute to ciguatera poisoning. Macroalgae samples were collected during research expeditions to Rarotonga (Cook Islands) and North Meyer Island (Kermadec Islands), from which two new Gambierdiscus species were characterized, G. cheloniae CAWD232 and G. honu CAWD242. Previous chemical and toxicological investigations of these species demonstrated that they did not produce the routinely monitored Pacific ciguatoxins nor maitotoxin-1 (MTX-1), yet were highly toxic to mice via intraperitoneal (i.p.) injection. Bioassay-guided fractionation of methanolic extracts, incorporating wet chemistry and chromatographic techniques, was used to isolate two new MTX analogs; MTX-6 from G. cheloniae CAWD232 and MTX-7 from G. honu CAWD242. Structural characterization of the new MTX analogs used a combination of analytical chemistry techniques, including LC–MS, LC–MS/MS, HR–MS, oxidative cleavage and reduction, and NMR spectroscopy. A substantial portion of the MTX-7 structure was elucidated, and (to a lesser extent) that of MTX-6. Key differences from MTX-1 included monosulfation, additional hydroxyl groups, an extra double bond, and in the case of MTX-7, an additional methyl group. To date, this is the most extensive structural characterization performed on an MTX analog since the complete structure of MTX-1 was published in 1993. MTX-7 was extremely toxic to mice via i.p. injection (LD50 of 0.235 µg/kg), although no toxicity was observed at the highest dose rate via oral administration (155.8 µg/kg). Future research is required to investigate the bioaccumulation and likely biotransformation of the MTX analogs in the marine food web.
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Affiliation(s)
- J. Sam Murray
- Cawthron Institute, Private Bag 2, Nelson 7040, New Zealand; (J.P.); (D.T.H.); (L.L.R.); (R.v.G.)
- New Zealand Food Safety Science and Research Centre, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand; (A.L.W.); (M.R.P.)
- Correspondence: ; Tel.: +64-3-548-2319
| | - Sarah C. Finch
- AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand;
| | - Elizabeth M. Mudge
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, NS B3H 3Z1, Canada;
| | - Alistair L. Wilkins
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand; (A.L.W.); (M.R.P.)
- Department of Chemistry, University of Oslo, Blindern, P.O. Box 1033, NO-0315 Oslo, Norway;
| | - Jonathan Puddick
- Cawthron Institute, Private Bag 2, Nelson 7040, New Zealand; (J.P.); (D.T.H.); (L.L.R.); (R.v.G.)
| | - D. Tim Harwood
- Cawthron Institute, Private Bag 2, Nelson 7040, New Zealand; (J.P.); (D.T.H.); (L.L.R.); (R.v.G.)
- New Zealand Food Safety Science and Research Centre, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
| | - Lesley L. Rhodes
- Cawthron Institute, Private Bag 2, Nelson 7040, New Zealand; (J.P.); (D.T.H.); (L.L.R.); (R.v.G.)
| | - Roel van Ginkel
- Cawthron Institute, Private Bag 2, Nelson 7040, New Zealand; (J.P.); (D.T.H.); (L.L.R.); (R.v.G.)
| | - Frode Rise
- Department of Chemistry, University of Oslo, Blindern, P.O. Box 1033, NO-0315 Oslo, Norway;
| | - Michèle R. Prinsep
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand; (A.L.W.); (M.R.P.)
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Boundy MJ, Harwood DT, Tommasi E, Burger E, van Ginkel R, Waugh C, Selwood AI, Finch S. Acute toxicity of decarbamoyl gonyautoxin 1&4 to mice by various routes of administration. Toxicon 2021; 204:56-63. [PMID: 34742781 DOI: 10.1016/j.toxicon.2021.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/08/2021] [Accepted: 11/02/2021] [Indexed: 11/16/2022]
Abstract
Saxitoxin and its derivatives, the paralytic shellfish toxins (PSTs), are well known to be toxic to humans, and maximum permitted levels in seafood have been established by regulatory authorities in many countries. Monitoring of PSTs is typically performed using chemical methods which quantify the concentration of the individual PST analogues, of which there are many. However, since the toxicities of analogues are different, they do not equally contribute to the overall toxicity of the sample. To account for these differences, toxicity equivalency factors (TEFs) need to be determined for each analogue and applied. Currently there are no established TEFs for decarbamoyl gonyautoxin 1&4 (dcGTX1&4), which occurs in some clam species such as Mactra chinensis contaminated with PSTs due to metabolism within the shellfish. In this study the median lethal dose of purified, equilibrated epimeric mixture of dcGTX1&4 has been determined by intraperitoneal injection (i.p.) (4.75 μmol/kg) and by feeding (34.9 μmol/kg). The most relevant route of exposure is orally with feeding being more representative of human consumption and more reliable than gavage. Based on the median lethal dose by feeding, a TEF of 0.1 is recommended for dcGTX1&4. Receptor binding activity and i.p. toxicity results showed dcGTX1&4 to be much less toxic than STX (140-170-fold). However, by feeding a much smaller difference in toxicity was observed with dcGTX1&4 being only 11-fold less toxic than STX. Analysis of the gut contents of mice dosed with dcGTX1&4 showed the presence of decarbamoyl gonyautoxin 2&3, decarbamoyl saxitoxin and decarbamoyl neosaxitoxin, all of which are of greater toxicity. This conversion of dcGTX1&4 within the digestive track to more toxic congeners may explain the high relative toxicity of dcGTX1&4 by feeding compared to that determined by i.p. and by sodium channel activity.
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Affiliation(s)
| | - D Tim Harwood
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - Elena Tommasi
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - Emillie Burger
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - Roel van Ginkel
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - Craig Waugh
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | | | - Sarah Finch
- AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, 3240, New Zealand
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Murray JS, Finch SC, Puddick J, Rhodes LL, Harwood DT, van Ginkel R, Prinsep MR. Acute Toxicity of Gambierone and Quantitative Analysis of Gambierones Produced by Cohabitating Benthic Dinoflagellates. Toxins (Basel) 2021; 13:toxins13050333. [PMID: 34063025 PMCID: PMC8147941 DOI: 10.3390/toxins13050333] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 04/29/2021] [Accepted: 05/03/2021] [Indexed: 01/05/2023] Open
Abstract
Understanding the toxicity and production rates of the various secondary metabolites produced by Gambierdiscus and cohabitating benthic dinoflagellates is essential to unravelling the complexities associated with ciguatera poisoning. In the present study, a sulphated cyclic polyether, gambierone, was purified from Gambierdiscus cheloniae CAWD232 and its acute toxicity was determined using intraperitoneal injection into mice. It was shown to be of low toxicity with an LD50 of 2.4 mg/kg, 9600 times less toxic than the commonly implicated Pacific ciguatoxin-1B, indicating it is unlikely to play a role in ciguatera poisoning. In addition, the production of gambierone and 44-methylgambierone was assessed from 20 isolates of ten Gambierdiscus, two Coolia and two Fukuyoa species using quantitative liquid chromatography–tandem mass spectrometry. Gambierone was produced by seven Gambierdiscus species, ranging from 1 to 87 pg/cell, and one species from each of the genera Coolia and Fukuyoa, ranging from 2 to 17 pg/cell. The production of 44-methylgambierone ranged from 5 to 270 pg/cell and was ubiquitous to all Gambierdiscus species tested, as well as both species of Coolia and Fukuyoa. The relative production ratio of these two secondary metabolites revealed that only two species produced more gambierone, G. carpenteri CAWD237 and G. cheloniae CAWD232. This represents the first report of gambierone acute toxicity and production by these cohabitating benthic dinoflagellate species. While these results demonstrate that gambierones are unlikely to pose a risk to human health, further research is required to understand if they bioaccumulate in the marine food web.
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Affiliation(s)
- J. Sam Murray
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
- New Zealand Food Safety Science and Research Centre, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand;
- Correspondence:
| | - Sarah C. Finch
- AgResearch, Ruakura Research Centre, Private Bag 3123, Hamilton 3240, New Zealand;
| | - Jonathan Puddick
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
| | - Lesley L. Rhodes
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
| | - D. Tim Harwood
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
- New Zealand Food Safety Science and Research Centre, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand
| | - Roel van Ginkel
- Cawthron Institute, Private Bag 2, Nelson 7042, New Zealand; (J.P.); (L.L.R.); (D.T.H.); (R.v.G.)
| | - Michèle R. Prinsep
- School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand;
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Puddick J, van Ginkel R, Page CD, Murray JS, Greenhough HE, Bowater J, Selwood AI, Wood SA, Prinsep MR, Truman P, Munday R, Finch SC. Acute toxicity of dihydroanatoxin-a from Microcoleus autumnalis in comparison to anatoxin-a. Chemosphere 2021; 263:127937. [PMID: 32828056 DOI: 10.1016/j.chemosphere.2020.127937] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/03/2020] [Accepted: 08/05/2020] [Indexed: 06/11/2023]
Abstract
The cyanobacterium Microcoleus autumnalis grows as thick benthic mats in rivers and is becoming increasingly prevalent around the world. M. autumnalis can produce high concentrations of anatoxins and ingestion of benthic mats has led to multiple dog deaths over the past two decades. M. autumnalis produces a suite of different anatoxin congeners including anatoxin-a (ATX), dihydroanatoxin-a, (dhATX), homoanatoxin-a and dihydrohomoanatoxin-a. Benthic mat samples often contain high levels of dhATX, but there is little toxicology information on this congener. In the present study, natural versions of dhATX and ATX were purified from cyanobacteria to determine the acute toxicity by different routes of administration using mice. Nuclear magnetic resonance spectroscopy was used to confirm the putative structure of dhATX. By intraperitoneal (ip) injection, the median lethal dose (LD50) for dhATX was 0.73 mg/kg, indicating a reduced toxicity compared to ATX (LD50 of 0.23 mg/kg). However, by oral administration (both gavage and feeding), dhATX was more toxic than ATX (gavage LD50 of 2.5 mg/kg for dhATX and 10.6 mg/kg for ATX; feeding LD50 of 8 mg/kg for dhATX and 25 mg/kg for ATX). The relative nicotinic acetylcholine receptor-binding affinities of ATX and dhATX were determined using the Torpedo electroplaque assay which showed consistency with the relative toxicity determined by ip injection. This work highlights that toxicity studies based solely on ip injection may not yield LD50 values that are relevant to those derived via oral administration, and hence, do not provide a good estimate of the risk posed to human and animal health in situations where oral ingestion is the likely route of exposure. The high acute oral toxicity of dhATX, and its abundance in M. autumnalis proliferations, demonstrates that it is an important environmental contaminant that warrants further investigation.
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Affiliation(s)
| | - Roel van Ginkel
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - Carrie D Page
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - J Sam Murray
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | | | - Joel Bowater
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | | | - Susanna A Wood
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - Michèle R Prinsep
- Chemistry, School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Penelope Truman
- Massey University, PO Box 756, Wellington, 6140, New Zealand
| | - Rex Munday
- AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, 3240, New Zealand
| | - Sarah C Finch
- AgResearch Limited, Ruakura Research Centre, Private Bag 3123, Hamilton, 3240, New Zealand
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Hellyer SD, Selwood AI, van Ginkel R, Munday R, Sheard P, Miles CO, Rhodes L, Kerr DS. In vitro labelling of muscle type nicotinic receptors using a fluorophore-conjugated pinnatoxin F derivative. Toxicon 2014; 87:17-25. [DOI: 10.1016/j.toxicon.2014.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 05/02/2014] [Accepted: 05/07/2014] [Indexed: 11/30/2022]
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Selwood AI, van Ginkel R, Harwood DT, McNabb PS, Rhodes LR, Holland PT. A sensitive assay for palytoxins, ovatoxins and ostreocins using LC-MS/MS analysis of cleavage fragments from micro-scale oxidation. Toxicon 2012; 60:810-20. [PMID: 22659542 DOI: 10.1016/j.toxicon.2012.05.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 05/24/2012] [Accepted: 05/24/2012] [Indexed: 11/15/2022]
Abstract
Palytoxin is a highly toxic non-proteinaceous marine natural product that can pass through the food chain and result in human illnesses. A recent review by the European Food Safety Authority concluded that palytoxin requires regulation in seafood and a limit of 30 μg kg⁻¹ for shellfish flesh was suggested. Current methods based on LC-MS detection of intact palytoxins do not have sufficient sensitivity to enforce this limit for palytoxin. To improve sensitivity for trace analysis, a novel screen approach has been developed that uses LC-MS/MS analysis of substructures generated by oxidative cleavage of vicinal diol groups present in the intact toxin. Oxidation of palytoxins, ovatoxins or ostreocins using periodic acid generates two nitrogen-containing aldehyde fragments; an amino aldehyde common to these toxins, and an amide aldehyde that may vary depending on toxin type. Conditions for micro-scale oxidation of palytoxin were optimised, which include a novel SPE cleanup and on-column oxidation step. Rapid analysis of cleavage fragments was established using LC-MS/MS. Linear calibrations were established for the amino aldehyde from a palytoxin reference standard, which is suitable for all known palytoxin-like compounds, and for the confirmatory amide aldehydes of palytoxin and ostreocin-D. Palytoxin recoveries (at 10 μg kg⁻¹) from shellfish and fish tissues were 114-119% (as amine aldehyde) and 90-115% (as amide aldehyde) with RSDs for both of ≤ 18% (all tissues, n = 12). The method LOD was determined to be approximately 1 ng mL⁻¹ and the LOQ 4 ng mL⁻¹, which corresponds to 10 μg kg⁻¹ in tissue (flesh of shellfish or fish). The method has potential for use in research and is sufficiently sensitive for regulatory testing, should it be required.
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Dowsett N, Hallegraeff G, van Ruth P, van Ginkel R, McNabb P, Hay B, O'Connor W, Kiermeier A, Deveney M, McLeod C. Uptake, distribution and depuration of paralytic shellfish toxins from Alexandrium minutum in Australian greenlip abalone, Haliotis laevigata. Toxicon 2011; 58:101-11. [PMID: 21640130 DOI: 10.1016/j.toxicon.2011.05.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 05/10/2011] [Accepted: 05/17/2011] [Indexed: 11/19/2022]
Abstract
Farmed greenlip abalone Haliotis laevigata were fed commercial seaweed-based food pellets or feed pellets supplemented with 8 × 10⁵ Alexandrium minutum dinoflagellate cells g⁻¹ (containing 12 ± 3.0 μg STX-equivalent 100 g⁻¹, which was mainly GTX-1,4) every second day for 50 days. Exposure of abalone to PST supplemented feed for 50 days did not affect behaviour or survival but saw accumulation of up to 1.6 μg STX-equivalent 100 g⁻¹ in the abalone foot tissue (muscle, mouth without oesophagus and epipodial fringe), which is ∼50 times lower than the maximum permissible limit (80 μg 100 g⁻¹ tissue) for PSTs in molluscan shellfish. The PST levels in the foot were reduced to 0.48 μg STX-equivalent 100 g⁻¹ after scrubbing and removal of the pigment surrounding the epithelium of the epipodial fringe (confirmed by both HPLC and LC-MS/MS). Thus, scrubbing the epipodial fringe, a common procedure during commercial abalone canning, reduced PST levels by ∼70%. Only trace levels of PSTs were detected in the viscera (stomach, gut, heart, gonad, gills and mantle) of the abalone. A toxin reduction of approximately 73% was observed in STX-contaminated abalone held in clean water and fed uncontaminated food over 50 days. The low level of PST uptake when abalone were exposed to high numbers of A. minutum cells over a prolonged period may indicate a low risk of PSP poisoning to humans from the consumption of H. laevigata that has been exposed to a bloom of potentially toxic A. minutum in Australia. Further research is required to establish if non-dietary accumulation can result in significant levels of PSTs in abalone.
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Affiliation(s)
- Natalie Dowsett
- South Australian Research and Development Institute, GPO Box 397, Adelaide, South Australia 5001, Australia
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Selwood AI, Miles CO, Wilkins AL, van Ginkel R, Munday R, Rise F, McNabb P. Isolation, structural determination and acute toxicity of pinnatoxins E, F and G. J Agric Food Chem 2010; 58:6532-6542. [PMID: 20408554 DOI: 10.1021/jf100267a] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Pinnatoxins and pteriatoxins are a group of cyclic imine toxins that have hitherto only been isolated from Japanese shellfish. As with other cyclic imine shellfish toxins, pinnatoxins cause rapid death in the mouse bioassay for lipophilic shellfish toxins, but there is no evidence directly linking these compounds to human illness. We have identified the known pinnatoxins A (1) and D (6), and the novel pinnatoxins E (7), F (8) and G (5), in a range of shellfish and environmental samples from Australia and New Zealand using LC-MS. After isolation from the digestive glands of Pacific oysters, the structures of the novel pinnatoxins were determined by mass spectrometry and NMR spectroscopy, and their LD(50) values were evaluated by ip administration to mice. Examination of the toxin structures, together with analysis of environmental samples, suggests that pinnatoxins F and G are produced separately in different dinoflagellates. Furthermore, it appears probable that pinnatoxin F (8) is the progenitor of pinnatoxins D (6) and E (7), and that pinnatoxin G (6) is the progenitor of both pinnatoxins A-C (1 and 2) and pteriatoxins A-C (3 and 4), via metabolic and hydrolytic transformations in shellfish.
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Bottein MYD, Fuquay JM, Munday R, Selwood AI, van Ginkel R, Miles CO, Loader JI, Wilkins AL, Ramsdell JS. Bioassay methods for detection of N-palmitoylbrevetoxin-B2 (BTX-B4). Toxicon 2010; 55:497-506. [DOI: 10.1016/j.toxicon.2009.09.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2009] [Revised: 09/23/2009] [Accepted: 09/30/2009] [Indexed: 11/26/2022]
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Carreira M, Charernsuk M, Eberhard M, Fey N, Ginkel RV, Hamilton A, Mul WP, Orpen AG, Phetmung H, Pringle PG. Anatomy of Phobanes. Diastereoselective Synthesis of the Three Isomers of n-Butylphobane and a Comparison of their Donor Properties. J Am Chem Soc 2009; 131:3078-92. [DOI: 10.1021/ja808807s] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Monica Carreira
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
| | - Manutsavin Charernsuk
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
| | - Michael Eberhard
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
| | - Natalie Fey
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
| | - Roel van Ginkel
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
| | - Alex Hamilton
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
| | - Wilhelmus P. Mul
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
| | - A. Guy Orpen
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
| | - Hirihataya Phetmung
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
| | - Paul G. Pringle
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, BS8 1TS, U.K., and Shell Global Solutions International B.V., P.O. Box 38000, 1030 BN Amsterdam
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Selwood AI, Ginkel RV, Wilkins AL, Munday R, Ramsdell JS, Jensen DJ, Cooney JM, Miles CO. Semisynthesis of S-desoxybrevetoxin-B2 and brevetoxin-B2, and assessment of their acute toxicities. Chem Res Toxicol 2008; 21:944-50. [PMID: 18335998 DOI: 10.1021/tx700441w] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Brevetoxins are neurotoxins associated with blooms of marine algae such as Karenia brevis and can accumulate in the marine food chain, causing intoxication of marine animals and people consuming seafood. Brevetoxin-B2 ( 5) is a toxic metabolite produced in shellfish exposed to algae that contain brevetoxin-B ( 1). S-Desoxybrevetoxin-B2 ( 4) has been proposed as a cometabolite produced during this transformation, and while LC-MS analyses suggest its presence in shellfish, it has not yet been isolated and characterized. Studies on these materials are severely constrained by the difficulty of obtaining and purifying them from natural sources. We have developed a convenient one-pot conversion of commercially available brevetoxin-B ( 1) into S-desoxybrevetoxin-B2 ( 4), and a simple method for converting 4 into brevetoxin-B2 ( 5). Full NMR and mass-spectral characterization of 4 and 5 confirmed their structures and showed that the ratio of diastereoisomers in the synthetic 4 and 5 was similar to that observed in naturally contaminated shellfish. The LD 50 values for 4, 5, and dihydrobrevetoxin-B ( 6) by ip injection in mice were 211, 400, and 250 microg/kg, respectively. The methodology for synthesis of brevetoxin metabolites should greatly facilitate toxicological, biochemical and immunochemical studies of these substances, as well as the production of analytical standards.
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Drent E, van Dijk R, van Ginkel R, van Oort B, Pugh RI. The first example of palladium catalysed non-perfectly alternating copolymerisation of ethene and carbon monoxide. Chem Commun (Camb) 2002:964-5. [PMID: 12123070 DOI: 10.1039/b111629k] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Non-alternating ethene-CO copolymerisation is catalysed by a new series of [P-O]Pd catalysts based on o-alkoxy derivatives of diphenylphosphinobenzene sulfonic acid.
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Affiliation(s)
- Eite Drent
- Shell Research and Technology Centre, Amsterdam Badhuisweg 3, 1031 CM Amsterdam, The Netherlands
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Drent E, van Dijk R, van Ginkel R, van Oort B, Pugh RI. Palladium catalysed copolymerisation of ethene with alkylacrylates: polar comonomer built into the linear polymer chain. Chem Commun (Camb) 2002:744-5. [PMID: 12119702 DOI: 10.1039/b111252j] [Citation(s) in RCA: 363] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Copolymerisation of ethene and alkylacrylates is catalysed by palladium modified with di(2-methoxyphenyl)phosphinobenzene-2-sulfonic acid (DOPPBS); a linear polymer is produced in which acrylate units are incorporated into the polyethylene backbone.
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Affiliation(s)
- Eite Drent
- Shell Research and Technology Centre, Amsterdam Badhuisweg 3, 1031 CM, Amsterdam, The Netherlands
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Koot WJ, van Ginkel R, Kranenburg M, Hiemstra H, Louwrier S, Moolenaar MJ, Speckamp W. Synthesis of statine from (S)-malic acid; stereocontrol via radical cyclization. Tetrahedron Lett 1991. [DOI: 10.1016/s0040-4039(00)92639-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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