1
|
Raposo-García S, Botana AM, Rey V, Costas C, Rodríguez-Santos L, Louzao MC, Vale C, Botana LM. Analytical and functional profiles of paralytic shellfish toxins extracted from Semele proficua and Senilia senilis from Angola. Heliyon 2024; 10:e25338. [PMID: 38356596 PMCID: PMC10864898 DOI: 10.1016/j.heliyon.2024.e25338] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 02/16/2024] Open
Abstract
Paralytic shellfish poisoning is a foodborne illness that typically derive from the consumption of shellfish contaminated with saxitoxin-group of toxins produced by dinoflagellates of the genus Gymnodinium, Alexandrium and Pyrodinium. N-sulfocarbamoyl, carbamate and dicarbamoyl are the most abundant. In 2007 and 2008 some episodes of PSP occurred in Angola where there is not monitoring program for shellfish contamination with marine biotoxins. Therefore, ten samples extracted from Semele proficua from Luanda Bay and Senilia senilis from Mussulo Bay, were analyzed by HPLC finding saxitoxin, decarbamoylsaxitoxin and other three compounds that have an unusual profile different to the known hydrophilic PSP toxins were found in different amounts and combinations. These new compounds were not autofluorescent, and they presented much stronger response after peroxide oxidation than after periodate oxidation. The compounds appear as peaks eluted at 2.5 and 5.6 min after periodate oxidation and 8.2 min after peroxide oxidation. Electrophysiological studies revealed that none of the three unknown compounds had effect at cellular level by decreasing the maximum peak inward sodium currents by blocking voltage-gated sodium channels. Thus, not contributing to PSP intoxication. The presence in all samples of saxitoxin-group compounds poses a risk to human health and remarks the need to further explore the presence of new compounds that contaminate seafood, investigating their activity and developing monitoring programs.
Collapse
Affiliation(s)
- Sandra Raposo-García
- Departamento de Farmacologia, IDIS, Universidad de Santiago de Compostela, Campus Universitario, 27002, Lugo, Spain
| | - Ana M. Botana
- Departamento de Química Analítica, Universidad de Santiago de Compostela, Campus Universitario, 27002, Lugo, Spain
| | - Verónica Rey
- Departamento de Química Analítica, Universidad de Santiago de Compostela, Campus Universitario, 27002, Lugo, Spain
| | - Celia Costas
- Departamento de Farmacologia, IDIS, Universidad de Santiago de Compostela, Campus Universitario, 27002, Lugo, Spain
| | - Luis Rodríguez-Santos
- Departamento de Farmacologia, IDIS, Universidad de Santiago de Compostela, Campus Universitario, 27002, Lugo, Spain
| | - M. Carmen Louzao
- Departamento de Farmacologia, IDIS, Universidad de Santiago de Compostela, Campus Universitario, 27002, Lugo, Spain
| | - Carmen Vale
- Departamento de Farmacologia, IDIS, Universidad de Santiago de Compostela, Campus Universitario, 27002, Lugo, Spain
| | - Luis M. Botana
- Departamento de Farmacologia, IDIS, Universidad de Santiago de Compostela, Campus Universitario, 27002, Lugo, Spain
| |
Collapse
|
2
|
Abal P, Louzao MC, Suzuki T, Watanabe R, Vilariño N, Carrera C, Botana AM, Vieytes MR, Botana LM. Toxic Action Reevaluation of Okadaic Acid, Dinophysistoxin-1 and Dinophysistoxin-2: Toxicity Equivalency Factors Based on the Oral Toxicity Study. Cell Physiol Biochem 2018; 49:743-757. [PMID: 30176657 DOI: 10.1159/000493039] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [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: 03/15/2018] [Accepted: 08/21/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Okadaic acid (OA) and the structurally related compounds dinophysistoxin-1 (DTX1) and dinophysistoxin-2 (DTX2) are marine phycotoxins that cause diarrheic shellfish poisoning (DSP) in humans due to ingestion of contaminated shellfish. In order to guarantee consumer protection, the regulatory authorities have defined the maximum level of DSP toxins as 160 µg OA equivalent kg-1 shellfish meat. For risk assessment and overall toxicity determination, knowledge of the relative toxicities of each analogue is required. In absence of enough information from human intoxications, oral toxicity in mice is the most reliable data for establishing Toxicity Equivalence Factors (TEFs). METHODS Toxins were administered to mice by gavage, after that the symptomatology and mice mortality was registered over a period of 24 h. Organ damage data were collected at necropsy and transmission electron microscopy (TEM) was used for ultrastructural studies. Toxins in urine, feces and blood were analyzed by HPLC-MS/MS. The evaluation of in vitro potencies of OA, DTX1 and DTX2 was performed by the protein phosphatase 2A (PP2A) inhibition assay. RESULTS Mice that received DSP toxins by gavage showed diarrhea as the main symptom. Those toxins caused similar gastrointestinal alterations as well as intestine ultrastructural changes. However, DSP toxins did not modify tight junctions to trigger diarrhea. They had different toxicokinetics and toxic potency. The lethal dose 50 (LD50) was 487 µg kg-1 bw for DTX1, 760 µg kg-1 bw for OA and 2262 µg kg-1 bw for DTX2. Therefore, the oral TEF values are: OA = 1, DTX1 = 1.5 and DTX2 = 0.3. CONCLUSION This is the first comparative study of DSP toxins performed with accurate well-characterized standards and based on acute toxicity data. Results confirmed that DTX1 is more toxic than OA by oral route while DTX2 is less toxic. Hence, the current TEFs based on intraperitoneal toxicity should be modified. Also, the generally accepted toxic mode of action of this group of toxins needs to be reevaluated.
Collapse
Affiliation(s)
- Paula Abal
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario, Lugo, Spain
| | - M Carmen Louzao
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario, Lugo, Spain
| | - Toshiyuki Suzuki
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Japan
| | - Ryuichi Watanabe
- National Research Institute of Fisheries Science, Japan Fisheries Research and Education Agency, Yokohama, Japan
| | - Natalia Vilariño
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario, Lugo, Spain
| | - Cristina Carrera
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario, Lugo, Spain
| | - Ana M Botana
- Facultad de Ciencias, Universidad de Santiago de Compostela, Campus Universitario, Lugo, Spain
| | - Mercedes R Vieytes
- Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario, Lugo, Spain
| | - Luis M Botana
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario, Lugo, Spain
| |
Collapse
|
3
|
Rey V, Botana AM, Alvarez M, Antelo A, Botana LM. Liquid Chromatography with a Fluorimetric Detection Method for Analysis of Paralytic Shellfish Toxins and Tetrodotoxin Based on a Porous Graphitic Carbon Column. Toxins (Basel) 2016; 8:toxins8070196. [PMID: 27367728 PMCID: PMC4963829 DOI: 10.3390/toxins8070196] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [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: 05/16/2016] [Revised: 06/21/2016] [Accepted: 06/23/2016] [Indexed: 01/12/2023] Open
Abstract
Paralytic shellfish toxins (PST) traditionally have been analyzed by liquid chromatography with either pre- or post-column derivatization and always with a silica-based stationary phase. This technique resulted in different methods that need more than one run to analyze the toxins. Furthermore, tetrodotoxin (TTX) was recently found in bivalves of northward locations in Europe due to climate change, so it is important to analyze it along with PST because their signs of toxicity are similar in the bioassay. The methods described here detail a new approach to eliminate different runs, by using a new porous graphitic carbon stationary phase. Firstly we describe the separation of 13 PST that belong to different groups, taking into account the side-chains of substituents, in one single run of less than 30 min with good reproducibility. The method was assayed in four shellfish matrices: mussel (Mytillus galloprovincialis), clam (Pecten maximus), scallop (Ruditapes decussatus) and oyster (Ostrea edulis). The results for all of the parameters studied are provided, and the detection limits for the majority of toxins were improved with regard to previous liquid chromatography methods: the lowest values were those for decarbamoyl-gonyautoxin 2 (dcGTX2) and gonyautoxin 2 (GTX2) in mussel (0.0001 mg saxitoxin (STX)·diHCl kg−1 for each toxin), decarbamoyl-saxitoxin (dcSTX) in clam (0.0003 mg STX·diHCl kg−1), N-sulfocarbamoyl-gonyautoxins 2 and 3 (C1 and C2) in scallop (0.0001 mg STX·diHCl kg−1 for each toxin) and dcSTX (0.0003 mg STX·diHCl kg−1 ) in oyster; gonyautoxin 2 (GTX2) showed the highest limit of detection in oyster (0.0366 mg STX·diHCl kg−1). Secondly, we propose a modification of the method for the simultaneous analysis of PST and TTX, with some minor changes in the solvent gradient, although the detection limit for TTX does not allow its use nowadays for regulatory purposes.
Collapse
Affiliation(s)
- Veronica Rey
- Department Analytical Chemistry, Faculty of Sciences, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Ana M Botana
- Department Analytical Chemistry, Faculty of Sciences, University of Santiago de Compostela, Lugo 27002, Spain.
| | | | - Alvaro Antelo
- CIFGA S.A., Plaza Santo Domingo 20-5ª, Lugo 27001, Spain.
| | - Luis M Botana
- Department Pharmacology, Veterinary Faculty, University of Santiago de Compostela, Lugo 27002, Spain.
| |
Collapse
|
4
|
Vlamis A, Katikou P, Rodriguez I, Rey V, Alfonso A, Papazachariou A, Zacharaki T, Botana AM, Botana LM. First Detection of Tetrodotoxin in Greek Shellfish by UPLC-MS/MS Potentially Linked to the Presence of the Dinoflagellate Prorocentrum minimum. Toxins (Basel) 2015; 7:1779-807. [PMID: 26008234 PMCID: PMC4448174 DOI: 10.3390/toxins7051779] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [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: 03/05/2015] [Revised: 04/25/2015] [Accepted: 05/11/2015] [Indexed: 12/21/2022] Open
Abstract
During official shellfish control for the presence of marine biotoxins in Greece in year 2012, a series of unexplained positive mouse bioassays (MBA) for lipophilic toxins with nervous symptomatology prior to mice death was observed in mussels from Vistonikos Bay–Lagos, Rodopi. This atypical toxicity coincided with (a) absence or low levels of regulated and some non-regulated toxins in mussels and (b) the simultaneous presence of the potentially toxic microalgal species Prorocentrum minimum at levels up to 1.89 × 103 cells/L in the area’s seawater. Further analyses by different MBA protocols indicated that the unknown toxin was hydrophilic, whereas UPLC-MS/MS analyses revealed the presence of tetrodotoxins (TTXs) at levels up to 222.9 μg/kg. Reviewing of official control data from previous years (2006–2012) identified a number of sample cases with atypical positive to asymptomatic negative MBAs for lipophilic toxins in different Greek production areas, coinciding with periods of P. minimum blooms. UPLC-MS/MS analysis of retained sub-samples from these cases revealed that TTXs were already present in Greek shellfish since 2006, in concentrations ranging between 61.0 and 194.7 μg/kg. To our knowledge, this is the earliest reported detection of TTXs in European bivalve shellfish, while it is also the first work to indicate a possible link between presence of the toxic dinoflagellate P. minimum in seawater and that of TTXs in bivalves. Confirmed presence of TTX, a very heat-stable toxin, in filter-feeding mollusks of the Mediterranean Sea, even at lower levels to those inducing symptomatology to humans, indicates that this emerging risk should be seriously taken into account by the EU to protect the health of shellfish consumers.
Collapse
Affiliation(s)
- Aristidis Vlamis
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
- National Reference Laboratory on Marine Biotoxins, Veterinary Centre of Thessaloniki, Ministry of Productive Reconstruction, Environment and Energy, 3A Limnou street, GR 54627 Thessaloniki, Greece.
| | - Panagiota Katikou
- National Reference Laboratory on Marine Biotoxins, Veterinary Centre of Thessaloniki, Ministry of Productive Reconstruction, Environment and Energy, 3A Limnou street, GR 54627 Thessaloniki, Greece.
| | - Ines Rodriguez
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Verónica Rey
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Amparo Alfonso
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Angelos Papazachariou
- National Reference Laboratory on Marine Biotoxins, Veterinary Centre of Thessaloniki, Ministry of Productive Reconstruction, Environment and Energy, 3A Limnou street, GR 54627 Thessaloniki, Greece.
| | - Thetis Zacharaki
- National Reference Laboratory on Marine Biotoxins, Veterinary Centre of Thessaloniki, Ministry of Productive Reconstruction, Environment and Energy, 3A Limnou street, GR 54627 Thessaloniki, Greece.
| | - Ana M Botana
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Luis M Botana
- Department of Pharmacology, Veterinary School, University of Santiago de Compostela, Lugo 27002, Spain.
| |
Collapse
|
5
|
Rey V, Alfonso A, Botana LM, Botana AM. Influence of different shellfish matrices on the separation of PSP toxins using a postcolumn oxidation liquid chromatography method. Toxins (Basel) 2015; 7:1324-40. [PMID: 25884908 PMCID: PMC4417969 DOI: 10.3390/toxins7041324] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [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: 03/03/2015] [Revised: 03/25/2015] [Accepted: 04/03/2015] [Indexed: 11/16/2022] Open
Abstract
The separation of PSP toxins using liquid chromatography with a post-column oxidation fluorescence detection method was performed with different matrices. The separation of PSP toxins depends on several factors, and it is crucial to take into account the presence of interfering matrix peaks to produce a good separation. The matrix peaks are not always the same, which is a significant issue when it comes to producing good, reliable results regarding resolution and toxicity information. Different real shellfish matrices (mussel, scallop, clam and oyster) were studied, and it was seen that the interference is not the same for each individual matrix. It also depends on the species, sampling location and the date of collection. It was proposed that separation should be accomplished taking into account the type of matrix, as well as the concentration of heptane sulfonate in both solvents, since the mobile phase varies regarding the matrix. Scallop and oyster matrices needed a decrease in the concentration of heptane sulfonate to separate GTX4 from matrix peaks, as well as dcGTX3 for oysters, with a concentration of 6.5 mM for solvent A and 6.25 mM for solvent B. For mussel and clam matrices, interfering peaks are not as large as they are in the other group, and the heptane sulfonate concentration was 8.25 mM for both solvents. Also, for scallops and oysters, matrix interferences depend not only on the sampling site but also on the date of collection as well as the species; for mussels and clams, differences are noted only when the sampling site varies.
Collapse
Affiliation(s)
- Verónica Rey
- Department of Analytical Chemistry, Science Faculty, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Amparo Alfonso
- Department of Pharmacology, Veterinary Faculty, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Luis M Botana
- Department of Pharmacology, Veterinary Faculty, University of Santiago de Compostela, Lugo 27002, Spain.
| | - Ana M Botana
- Department of Analytical Chemistry, Science Faculty, University of Santiago de Compostela, Lugo 27002, Spain.
| |
Collapse
|
6
|
Perez S, Vale C, Botana AM, Alonso E, Vieytes MR, Botana LM. Determination of Toxicity Equivalent Factors for Paralytic Shellfish Toxins by Electrophysiological Measurements in Cultured Neurons. Chem Res Toxicol 2011; 24:1153-7. [DOI: 10.1021/tx200173d] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sheila Perez
- Departamento de Farmacología, Facultad de Veterinaria, USC, Lugo, Spain
| | - Carmen Vale
- Departamento de Farmacología, Facultad de Veterinaria, USC, Lugo, Spain
| | | | - Eva Alonso
- Departamento de Farmacología, Facultad de Veterinaria, USC, Lugo, Spain
| | | | | |
Collapse
|
7
|
Botana LM, Vilariño N, Alfonso A, Vale C, Louzao C, Elliott CT, Campbell K, Botana AM. The problem of toxicity equivalent factors in developing alternative methods to animal bioassays for marine-toxin detection. Trends Analyt Chem 2010. [DOI: 10.1016/j.trac.2010.09.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
8
|
Otero P, Alfonso A, Alfonso C, Vieytes MR, Louzao MC, Botana AM, Botana LM. New protocol to obtain spirolides from Alexandrium ostenfeldii cultures with high recovery and purity. Biomed Chromatogr 2010; 24:878-86. [PMID: 20087843 DOI: 10.1002/bmc.1380] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The aim of this work was to develop a method to purify large amounts of spirolide toxins from cultures of Alexandrium ostenfeldii. The dinoflagellates grew in batches under controlled conditions of salinity, light and temperature. Analysis of the cultures demonstrated the existence of neurotoxins associated with paralytic shellfish poisoning toxins and two spirolides, 13-desmethyl spirolide C and 13,19-didesmethyl spirolide C. The protocol designed presents several stages of extraction, separation between spirolides and paralytic shellfish poisoning toxins, and cleanup in solid-phase extraction. Finally, the purification of spirolides was conducted by a preparative high-performance liquid chromatography system coupled to a mass spectrometer detector. The purity and the amount of both toxins in each step was monitored by analytical liquid chromatographic-mass spectrometry. Large amounts of 13-desMeC, 97% pure, and 13,19-didesMeC, 99% pure, were obtained. A novel and efficient method to separate and purify spirolide toxins from large amounts of phytoplankton is provided. The protocol proposed shows, for the first time, a complete and detailed methodology to separate and purify spirolide toxins with high purity, recovery, repeatability and stability.
Collapse
Affiliation(s)
- Paz Otero
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, 27002 Lugo, Spain
| | | | | | | | | | | | | |
Collapse
|
9
|
Vale C, Alfonso A, Vieytes MR, Romarís XM, Arévalo F, Botana AM, Botana LM. In Vitro and in Vivo Evaluation of Paralytic Shellfish Poisoning Toxin Potency and the Influence of the pH of Extraction. Anal Chem 2008; 80:1770-6. [DOI: 10.1021/ac7022266] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Carmen Vale
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n, 27002, Lugo, Spain, Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain, INTECMAR, Vilaxoan, Pontevedra, Spain, and Departamento de Química Analítica, Facultad de Ciencias, Universidad de Santiago de Compostela, Lugo, Spain
| | - Amparo Alfonso
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n, 27002, Lugo, Spain, Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain, INTECMAR, Vilaxoan, Pontevedra, Spain, and Departamento de Química Analítica, Facultad de Ciencias, Universidad de Santiago de Compostela, Lugo, Spain
| | - Mercedes R. Vieytes
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n, 27002, Lugo, Spain, Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain, INTECMAR, Vilaxoan, Pontevedra, Spain, and Departamento de Química Analítica, Facultad de Ciencias, Universidad de Santiago de Compostela, Lugo, Spain
| | - Xosé Manuel Romarís
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n, 27002, Lugo, Spain, Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain, INTECMAR, Vilaxoan, Pontevedra, Spain, and Departamento de Química Analítica, Facultad de Ciencias, Universidad de Santiago de Compostela, Lugo, Spain
| | - Fabiola Arévalo
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n, 27002, Lugo, Spain, Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain, INTECMAR, Vilaxoan, Pontevedra, Spain, and Departamento de Química Analítica, Facultad de Ciencias, Universidad de Santiago de Compostela, Lugo, Spain
| | - Ana M. Botana
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n, 27002, Lugo, Spain, Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain, INTECMAR, Vilaxoan, Pontevedra, Spain, and Departamento de Química Analítica, Facultad de Ciencias, Universidad de Santiago de Compostela, Lugo, Spain
| | - Luis M. Botana
- Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Campus Universitario s/n, 27002, Lugo, Spain, Departamento de Fisiología, Facultad de Veterinaria, Universidad de Santiago de Compostela, Lugo, Spain, INTECMAR, Vilaxoan, Pontevedra, Spain, and Departamento de Química Analítica, Facultad de Ciencias, Universidad de Santiago de Compostela, Lugo, Spain
| |
Collapse
|
10
|
González JC, Vieytes MR, Botana AM, Vieites JM, Botana LM. Modified mass action law-based model to correlate the solubility of solids and liquids in entrained supercritical carbon dioxide. J Chromatogr A 2001; 910:119-25. [PMID: 11263564 DOI: 10.1016/s0021-9673(00)01120-1] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The solubility of solids and liquids in supercritical CO2 with added entrainers was modeled with a modified version of the equation of Chrastil to include the effect of entrainers. By considering the formation of the solute-entrainer-solvent complexes an equation is obtained which predicts an exponential increase of solubility with fluid density and/or entrainer concentration. The correlating model was tested by non-linear regression through a computerized iterative process for several systems where an entrainer was present. Four experimental parameters are easily regressed from experimental data, hence the corresponding properties of components such as chemical potentials or critical parameters are not needed. Instead of its simplicity, this thermodynamical model provided a good correlation of the solubility enhancement in the presence of entrainer effect.
Collapse
Affiliation(s)
- J C González
- Departamento de Farmacologia, Facultad de Veterinaria, Universidade de Santiago de Compostela, Lugo, Spain
| | | | | | | | | |
Collapse
|
11
|
González JC, Leira F, Vieytes MR, Vieites JM, Botana AM, Botana LM. Development and validation of a high-performance liquid chromatographic method using fluorimetric detection for the determination of the diarrhetic shellfish poisoning toxin okadaic acid without chlorinated solvents. J Chromatogr A 2000; 876:117-25. [PMID: 10823507 DOI: 10.1016/s0021-9673(00)00193-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A modification of the high-performance liquid chromatographic method with fluorimetric detection method for the determination of diarrhetic shellfish poisoning toxins was developed to completely avoid the use of dangerous chlorinated solvents. The method was validated for the toxin okadaic acid (OA) over a period of 6 months where 12 calibrations were performed and 72 samples were analyzed. Analysis of toxic and non-toxic mussels, clams and scallops demonstrated its selectivity. Linearity was observed in the tested range of interest for monitoring purposes of edible shellfish, from the limit of detection (0.3 microg OA/g hepatopancreas) to 13 microg OA/g hepatopancreas. Intra-assay precision of the method was 7% RSD at the quantification limit (0.97 microg OA/g hepatopancreas at S/N=10). Accuracy was tested in triplicate recovery experiments from OA-spiked shellfish where recovery ranged from 92 to 106% in the concentration range of 0.8 to 3.6 microg OA/g hepatopancreas. Useful information on critical factors affecting calibration and reproducibility is also reported. Good correlation (R=0.87) was observed between the results of the method and those of the method of Lee, after the analysis of 45 samples of mussels from the galician rias.
Collapse
Affiliation(s)
- J C González
- Departamento de Farmacología, Universidad de Santiago de Compostela, Lugo, Spain
| | | | | | | | | | | |
Collapse
|
12
|
|
13
|
Louzao MC, Alfonso A, Botana AM, Goenaga X, Cabado AG, Vieytes MR, Botana LM. Effect of lyophilization on the stability of gonyautoxins obtained from contaminated mussels. Toxicon 1994; 32:807-17. [PMID: 7940588 DOI: 10.1016/0041-0101(94)90006-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This study describes the stability of gonyautoxins (GTX) and C toxins obtained from contaminated mussels and stored at different temperatures in lyophilized samples. Analyses of extracts from mussels contaminated with paralytic shellfish poison (PSP) indicated the presence of gonyautoxins as the major component in red tides of the North-West coast of Spain. These GTX and C toxins were extracted from contaminated mussels (Mytilus galloprovincialis Lmk) and partially purified by chromatography on Bio-Gel P-2 and Bio-Rex 70. The stability of these toxins was analysed by high performance liquid chromatography. GTX 4 and GTX 6 are the most stable toxins among GTX. We conclude that the lyophilization procedure is not the safest way to process most of the gonyautoxins. However, the lyophilization procedure made the C toxins unstable, so clearly this procedure must be rejected.
Collapse
Affiliation(s)
- M C Louzao
- Departamento de Farmacología, Facultad de Veterinaria, Lugo, Spain
| | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Sodium channels obtained from rat brain membrane preparations were coated onto microtiter plates and used to develop a direct solid-phase binding assay. The tritiated sodium channel blocker saxitoxin ([3H]-saxitoxin; STX) was used to detect toxins in paralytic shellfish poisoning (PSP) by measuring the competitive displacement of other toxins. With this assay the amount of STX and tetrodotoxin needed to displace 50% of bound [3H]STX was 1.7 and 1.76 ng/ml for buffer samples, respectively. In the direct solid-phase binding assays, the PSP toxins were effectively bound to the rat brain membranes. The IC50 of this assay for different PSP toxin solutions obtained from mussels contaminated in red tides ranged from 0.03 to 0.30 ng/ml. Therefore, this assay represents a potentially useful method for the detection of toxin-contaminated mussels.
Collapse
Affiliation(s)
- M R Vieytes
- Departmento de Fisiologiá, Facultad de Veterinaria, Lugo, Spain
| | | | | | | | | | | |
Collapse
|