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1.
Methods Mol Biol ; 1308: 277-97, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26108513

RESUMO

Different clinical types of algae-related poisoning have attracted scientific and commercial attention: paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP). Bioassays are common methods for the determination of marine biotoxins. However, biological tests are not completely satisfactory, mainly due to the low sensitivity and the absence of specialized variations. In this context LC-MS methods replaced HPLC methods with optical detectors, allowing both effective seafood control and monitoring of phytoplankton in terms of the different groups of marine biotoxins. This chapter describes state-of-the-art LC-MS/MS methods for the detection and quantitation of different classes of phycotoxins in shellfish matrices. These classes include the highly hydrophilic paralytic shellfish poisoning (PSP) toxins. Hydrophilic interaction liquid chromatography (HILIC) has been shown to be useful in the separation of PSP toxins and is described in detail within this chapter. Another important class of phycotoxins is diarrhetic shellfish poisoning (DSP) toxins. This group traditionally comprises okadaic acid and dinophysistoxins (DTXs), pectenotoxins (PTXs), and yessotoxins (YTXs). The most recently described shellfish poisoning syndrome, azaspiracid shellfish poisoning (AZP) is caused by azaspiracids, which in turn are diarrhetic, but usually are treated separately as AZP. The last group of regulated shellfish toxins is the amnesic shellfish poisoning (ASP) toxin domoic acid, produced by species of the genus Pseudo-nitzschia.


Assuntos
Toxinas Marinhas/análise , Frutos do Mar/análise , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida/métodos , Ácido Caínico/análogos & derivados , Ácido Caínico/análise , Ácido Okadáico/análise , Oxocinas/análise , Piranos/análise , Compostos de Espiro/análise
2.
Toxicology ; 293(1-3): 59-67, 2012 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-22230684

RESUMO

Contamination of water, foods and food supplements by various genera of cyanobacteria is a serious health problem worldwide for humans and animals, largely due to the toxic effects of microcystins (MCs) and nodularin (NOD), a group of hepatotoxic cyclic peptides. The toxins occur in variable structures resulting in more than 90 different MCs and 8 different NODs, many of them not having been investigated for their toxic potency. Potent MCs such as MC-LR have been shown to elicit their hepatotoxic potency via inhibition of hepatic protein phosphatases (PP) 1 and 2A leading to over-phosphorylation of vital cellular proteins. This mechanism of action is also thought to be responsible for the long term tumor promoting action of certain MCs and NOD in the liver. Here, we report on the isolation of certain MCs and NOD as well as a number of their desmethylated derivatives from algae bloom. Subsequently, we determined the cytotoxicity of these compounds in isolated primary human and rat hepatocytes in culture. In parallel experiments, we analyzed the inhibitory potency of these congeners on PP1 and 2A using commercially available enzymes. We found in primary rat hepatocytes that MC-LR, -YR and NOD were cytotoxic, namely in the 10 to >50 nM range, while MC-RR was not. The desmethylated congeners of MC-LR, -YR, and NOD were equally or more-toxic as/than their fully methylated counterparts. In primary human hepatocytes we could show that MC-LR, NOD and the desmethylated variants [³Asp]MC-LR, [7Dha]MC-LR and [¹Asp]NOD were cytotoxic in the 20 to >600 nM range. Inhibition data with human, bovine and rabbit protein phosphatases 1 and 2A were roughly in accordance with the cytotoxicity findings in human and rat hepatocytes, i.e. desmethylation had no pronounced effects on the inhibitory potencies. Thus, a variety of naturally occurring desmethylated MC and NOD congeners have to be considered as being at least as toxic as the corresponding fully methylated derivatives.


Assuntos
Inibidores Enzimáticos/toxicidade , Hepatócitos/efeitos dos fármacos , Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Peptídeos Cíclicos/toxicidade , Proteína Fosfatase 1/antagonistas & inibidores , Proteína Fosfatase 2/antagonistas & inibidores , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Alemanha , Proliferação Nociva de Algas , Humanos , Concentração Inibidora 50 , Isoenzimas/antagonistas & inibidores , Cinética , Masculino , Toxinas Marinhas/química , Toxinas Marinhas/isolamento & purificação , Toxinas Marinhas/farmacologia , Metilação , Microcistinas/química , Microcistinas/isolamento & purificação , Microcistinas/farmacologia , Microcystis/isolamento & purificação , Microcystis/metabolismo , Nodularia/isolamento & purificação , Nodularia/metabolismo , Peptídeos Cíclicos/química , Peptídeos Cíclicos/isolamento & purificação , Peptídeos Cíclicos/farmacologia , Ratos , Ratos Wistar
3.
Microb Ecol ; 63(1): 199-209, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21710225

RESUMO

Microcystis aeruginosa isolated in 2005 from the shallow eutrophic Lake Chao (Anhui, China) was investigated in terms of growth parameters and microcystin production under varying nutrient concentrations (P, N) and pH values (abiotic factors) as well as under the influence of spent medium of the non-toxic cyanobacterium Synechocystis sp. (biotic factors). Stimulating effects on growth were observed at the alkaline pH value (10.5), whereas toxin production was significantly increased under phosphate-P limitation (0.6 mg L(-1) medium). Within a broad range of nitrate-N concentrations (41.2-247.2 mg L(-1) medium), no significant influence on cell growth and microcystin production was observed; however, N-starvation resulted in a typical decrease of growth and toxicity. In addition, cryopreservation of M. aeruginosa evidenced the decrease of toxin production by time-dependent exposure with the cryoprotectant dimethyl sulfoxide under thawing conditions without affecting the growth of the cyanobacterial cells.


Assuntos
Toxinas Bacterianas/biossíntese , Lagos/microbiologia , Microcistinas/biossíntese , Microcystis/crescimento & desenvolvimento , Microcystis/metabolismo , China , Criopreservação , Meios de Cultivo Condicionados , Concentração de Íons de Hidrogênio , Microcystis/isolamento & purificação , Nitratos/metabolismo , Nitrogênio/metabolismo , Fosfatos/metabolismo , Synechocystis
4.
Toxicon ; 56(8): 1520-4, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20854832

RESUMO

Lake Chao, China, is highly eutrophicated and experiences recurrent dense cyanobacterial blooms. Its surface water is used as drinking water resource for Hefei city, hence the potential toxicity of those cyanobacteria was of interest. Sixteen isolated strains of Microcystis aeruginosa evidenced that non-toxic, toxic and highly toxic strains coexist in the lake. Microcystin variants within one strain ranged up to 11, the concentration up to 4.799 mg g DW(-1). Mass spectrometry analysis confirmed desmethylated microcystin variants.


Assuntos
Toxinas Bacterianas/química , Microcystis/química , Água/química , Toxinas Bacterianas/análise , China , Cromatografia Líquida , Monitoramento Ambiental , Espectrometria de Massas , Microcystis/genética , Microcystis/isolamento & purificação , Medição de Risco , Abastecimento de Água
5.
Toxicon ; 56(5): 731-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19682482

RESUMO

Ciguatera fish poisoning characterizes the intoxication caused by consumption of fish from tropical and subtropical areas, which have accumulated ciguatoxins (CTXs). The observed pattern of ciguatoxins in fish highly depends on the marine region and the causative organisms. It is evident that differences exist between ciguatoxins produced by certain strains of the dinoflagellate Gambierdiscus toxicus and other Gambierdiscus spp. In this context cultured strains purchased from the Provasoli-Guillard National Center for Culture of Marine Phytoplankton (CCMP) and strains from Vietnam were analyzed. Besides, lyophilized samples of several Gambierdiscus spp. from the National Oceanic and Atmospheric Administration (NOAA), USA and lyophilized samples of G. toxicus from Vietnam were analyzed. The latter has been cultured at different salinities. We observed differences between the toxin ratios of the analogues in the strain from Vietnam depending on the salinity. The CTX profiles of the Vietnamese samples were compared with cultures of Gambierdiscus spp. from CCMP and the National Oceanic and Atmospheric Administration (NOAA) resulting in an overview of toxins in cultures from different regions. Hence, it was obvious that the strain from Vietnam forms a characteristic CTX profile which is not directly comparable to CTX pattern observed in other tropical marine regions.


Assuntos
Ciguatoxinas/química , Dinoflagelados/química , Cromatografia Líquida de Alta Pressão/métodos , Dinoflagelados/classificação , Especificidade da Espécie , Espectrometria de Massas em Tandem/métodos
6.
Toxicon ; 55(2-3): 547-57, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19825383

RESUMO

Since diverse taxa of cyanobacteria has been linked to biosynthesis of BMAA, a controversy has arisen about the detection of neurotoxic amino acids in cyanobacteria. In this context, a novel LC-MS/MS method was developed for the unambiguous determination of beta-N-methylamino-L-alanine (BMAA) and 2,4-diaminobutyric acid (DAB) in cyanobacteria and selected plant seeds. Both neurotoxic and non-proteinogenic amino acids were analyzed without derivatization considering the total concentration of the free and protein-bound form. The investigation of overall 62 cyanobacterial samples of worldwide origin by application of this method revealed the absence of BMAA, whereas seeds of Cycas revoluta contained 6.96 microg g(-1) of free BMAA. In contrast, the isomer DAB was confirmed in 16 cyanobacterial samples in concentrations of 0.07-0.83 microg g(-1),whereof one sample is distributed as nutritional supplement. In addition, seeds of Lathyrus latifolius contained 4.21 microg g(-1) of free DAB. Limits of detection were for BMAA<1.0 microg g(-1) in the cyanobacterial matrix and<0.14 microg g(-1) in angiosperm seeds. DAB exhibits higher sensitivities of <0.06 microg g(-1) in cyanobacteria and <0.008 microg g(-1) in angiosperm seeds. The highly specific analysis method with increased detection sensitivity eliminates the disadvantages of derivatization-based methods to be discussed.


Assuntos
Diamino Aminoácidos/análise , Aminobutiratos/análise , Cianobactérias/química , Cycas/química , Lathyrus/química , Neurotoxinas/análise , Cromatografia Líquida de Alta Pressão , Suplementos Nutricionais/análise , Isomerismo , Sementes/química , Espectrometria de Massas em Tandem
7.
Biofactors ; 35(5): 460-7, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19798733

RESUMO

Epidemiological studies suggest that high fish intake is associated with a decreased risk of colorectal cancer which has been linked to the high content of the n - 3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in some fish. In this study, two different cell lines are compared in relation to their response to EPA and DHA versus the plant derived PUFAs, linoleic acid (LA), gamma-linolenic acid (GLA), and alpha-linolenic acid (ALA) and to the ubiquitous arachidonic acid (ARA). The uptake of 100 microM of each fatty acid (FA) was determined using GC. The 4',6-diamidino-2-phenylindole assay for DNA quantification and the Cell-Titer-Blue assay were used to determine cell survival and metabolic activity at 2-72 h after treatment. All FAs were utilized more efficiently by the human colon adenoma cell line LT97 than by the adenocarcinoma cell line HT29. LT97 were more susceptible than HT29 cells to the growth inhibitory activities of all FAs except for DHA where both were equally sensitive. Inhibition of survival and metabolic activity by EPA and DHA increased with treatment time in both cell lines. ALA or GLA were less growth inhibitory than EPA or DHA and ARA had intermediary activity. The data show that the tested FAs are incorporated into colon cells. Furthermore, adenoma cells are more susceptible than the adenocarcinoma cells.


Assuntos
Ácidos Graxos/farmacologia , Adenocarcinoma/metabolismo , Adenoma/metabolismo , Ácido Araquidônico/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Ácidos Docosa-Hexaenoicos/farmacologia , Ácido Eicosapentaenoico/farmacologia , Ácidos Graxos/metabolismo , Células HT29 , Humanos , Ácido Linoleico , Ácido alfa-Linoleico/farmacologia , Ácido gama-Linolênico/farmacologia
8.
Toxicon ; 54(6): 891-4, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19560484

RESUMO

The accumulation of saxitoxins (STXs) in fish from freshwater aquaculture was investigated for the first time in the present study. Cyanotoxins have been monitored in liver and muscle samples of Oreochromis niloticus by chromatographic methods, both before and after the depuration process. The results show that tilapia can accumulate STXs. Our findings suggest that depuration with clean water is an alternative process to eliminate STXs from fish and, therefore, improve the safety of tilapia for consumers.


Assuntos
Saxitoxina/metabolismo , Alimentos Marinhos , Tilápia/metabolismo , Animais , Cromatografia Líquida , Água Doce , Humanos
9.
Toxicon ; 54(3): 302-12, 2009 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-19397919

RESUMO

The periodical occurrence of harmful algal blooms (HABs) in freshwater lakes requires the determination of potential cyanobacterial toxins, especially microcystins (MCs). On demand of an adequate risk assessment, the high diversity of these hepatotoxic cyclic heptapeptides implicates the need of an unambiguous detection of their specific structural variants. Therefore, LC-MS and LC-MS/MS methods are the approaches of choice for determination of MCs. In contrast, even tandem mass spectromic fragmentation patterns are not even sufficient in any kind of structural determination requirements, whereas NMR methods require very high amounts of MCs. In this study, we present a novel method for chromatographic separation of desmethylated microcystins (dm-MCs). Based on the isolation of the specific structural variants using semi-preparative HPLC, a method was developed for the structure elucidation of cyclic peptides with special appliance for the determination of dm-MCs via analysis of the specific amino acid composition after peptide hydrolysis followed by stereospecific detection of the amino acids and resulting keto acids. On the basis of this method it is demonstrated that dm-MC-RR with the structure [Dha(7)]MC-RR represented the major compound in the microcystin pattern of Microcystis aeruginosa bloom events in 2005 and 2006 in Lake Senftenberg, Germany.


Assuntos
Fígado/efeitos dos fármacos , Microcistinas/toxicidade , Peptídeos Cíclicos/química , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Peptídeos Cíclicos/toxicidade , Conformação Proteica , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Ultravioleta , Espectrometria de Massas em Tandem
10.
Toxicon ; 51(5): 934-40, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18262215

RESUMO

Spirolides are biologically active macrocycles isolated first from scallops and phytoplankton from aquaculture sites in Nova Scotia, Canada. These compounds displayed "fast-acting" toxicity in the traditional bioassay. That phenomenon is related to the presence of a cyclic imine function in these compounds. Spirolides containing vicinal methyl groups in their seven-membered ring are suspected of being resistant to hydrolysis. We studied possible conversions of vicinal methyl groups wearing spirolides of Alexandrium ostenfeldii KO287 in enzymatic cell-free tissue extracts of Mytilus edulis, Pecten maximus and Crassostrea gigas. Our observations suggest that spirolides that contain an extra methyl group on the imine ring compared with spirolide A and B survive enzymatic hydrolysis conditions in shellfish and therefore may be toxic for human beings when shellfish is consumed.


Assuntos
Lactonas/metabolismo , Compostos de Espiro/metabolismo , Animais , Sistema Livre de Células , Crassostrea/metabolismo , Dinoflagelados/metabolismo , Lactonas/química , Estrutura Molecular , Mytilus edulis/metabolismo , Pecten/metabolismo , Compostos de Espiro/química
11.
Anal Bioanal Chem ; 391(1): 117-34, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18084747

RESUMO

The frequency of occurrence and intensity of harmful algal blooms (HABs) appear to be increasing on a global scale. Consequently, methods were established for the evaluation of possible hazards caused by the enrichment of algal toxins in the marine food chain. Different clinical types of algae-related poisoning have attracted scientific attention: paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP). In several countries fish specialties are consumed which may be contaminated with algal toxins typical for the respective region (e.g., ciguatera and tetrodotoxins). Bioassays are common methods for the determination of marine biotoxins. However, biological tests are not completely satisfactory, due to the low sensitivity and the absence of specialized variations. Moreover, there is growing resistance against the use of animal experiments. Therefore, many efforts have been made to determine algal toxins with chemical methods. In this context LC-MS methods replaced HPLC methods with optical detectors, allowing both effective seafood control and monitoring of phytoplankton in terms of the different groups of marine biotoxins.


Assuntos
Cromatografia Líquida , Toxinas Marinhas/análise , Espectrometria de Massas , Animais , Bioensaio/métodos , Cromatografia Líquida/métodos , Humanos , Toxinas Marinhas/química , Toxinas Marinhas/toxicidade , Espectrometria de Massas/métodos , Camundongos , Alimentos Marinhos/análise , Controle Social Formal
12.
Anal Bioanal Chem ; 389(6): 1997-2002, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17899030

RESUMO

Tetrodotoxin (TTX) and its analogs (TTXs), widely distributed among marine as well as terrestrial animals, induce dangerous intoxications. These highly potential toxins are also known as the causative agent of puffer fish poisoning. A newly developed highly sensitive method for determination of TTXs based on hydrophilic interaction chromatography and mass-spectrometric detection is presented. TTX, anhydrotetrodotoxin, 11-deoxytetrodotoxin and trideoxytetrodotoxin were determined in separated tissues of Bangladeshi marine puffers, Takifugu oblongus. TTX was predominant in skin, muscle and liver, whereas trideoxytetrodotoxin preponderated in the ovary. The toxicity of the various tissues was determined by a mouse bioassay.


Assuntos
Peixes Venenosos/metabolismo , Tetraodontiformes/metabolismo , Tetrodotoxina/análise , Animais , Bangladesh , Bioensaio , Cromatografia , Feminino , Espectrometria de Massas , Camundongos , Ovário/química , Ovário/metabolismo , Tetrodotoxina/análogos & derivados , Tetrodotoxina/farmacocinética , Distribuição Tecidual
13.
J Sep Sci ; 30(12): 1821-6, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17638360

RESUMO

A novel method for paralytic shellfish poisoning (PSP) toxins which is based on the chromatographic separation of the toxins using a zwitterionic (ZIC) hydrophilic interaction chromatography (HILIC) column is presented. Efficient retention of the polar PSP toxins on the ZIC-HILIC column allowed their selective and sensitive determination by the application of mass spectrometric (MS/MS) detection or as derivatives after oxidation prior to fluorescence detection (FD). Low buffer concentrations and the omission of ion-pair reagents decreased the limits of detection (LODs) by MS/MS analysis and showed a good linearity for both methods of detection. This method can be applied for the qualitative and quantitative determination of PSP toxins in various types of phytoplankton, and for the routine analysis of seafood.


Assuntos
Cromatografia/métodos , Toxinas Marinhas/análise , Saxitoxina/análise , Animais , Cromatografia Líquida/métodos , Íons , Toxinas Marinhas/isolamento & purificação , Espectrometria de Massas , Modelos Químicos , Conformação Molecular , Fitoplâncton/metabolismo , Reprodutibilidade dos Testes , Saxitoxina/isolamento & purificação , Frutos do Mar , Espectrometria de Fluorescência , Fatores de Tempo
14.
J Mass Spectrom ; 42(9): 1238-50, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17657826

RESUMO

We established an analytical method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in the precursor ion mode for simultaneous qualitative monitoring of various groups of cyanobacterial toxins. The toxin groups investigated were paralytic shellfish poisoning (PSP) toxins, anatoxins (ANAs), cylindrospermopsins (CYNs), microcystins (MCs), and nodularins (NODs), including rare and uncharacterized derivatives found in plankton and water matrices. Alternative analytical methods based on tandem mass spectrometry commonly operate in multiple reaction monitoring (MRM) mode and depend on prior knowledge of putative toxigenicity of the cyanobacterium species and strain, and the expected toxin variants. In contrast, the precursor ion mode yields diagnostic mass fragments for the detection of characteristic compounds of the different toxin classes and thus allows monitoring of a large set of unspecified cyanotoxins of various groups, even when the species composition is undetermined or uncertain. This rapid method enables screening for a wide spectrum of toxic cyanobacterial metabolites and degradation products in a single chromatographic separation with detection limits at nanogram levels. The precursor ion technique is a valuable adjunct to existing mass spectrometric methods for cyanotoxins, although it is not a complete replacement for detailed quantitative analysis requiring comprehensive sample cleanup.


Assuntos
Toxinas Bacterianas/análise , Toxinas Marinhas/análise , Microcistinas/análise , Toxinas Biológicas/análise , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos
15.
Toxicon ; 50(4): 518-29, 2007 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-17585981

RESUMO

The growth and toxin production of a Philippine Pyrodinium bahamense isolate in nutrient replete batch cultures were investigated under conditions affected by varying salinity, temperature and combined effects of salinity and temperature. Early exponential growth stage was reached after 7 days with a cell division rate of 0.26 div day(-1). The toxin content reached a peak of 298 fmol cell-1 at mid exponential phase and rapidly declined to 54 fmol cell-1 as it approached the death phase. Only three sets of toxins composed of STX, dcSTX and B1 were detected in which STX made up to 85-98 mol%toxincell-1. P. bahamense was able to grow in salinities and temperatures ranging from 26 per thousand to 36 per thousand and 23 to 36 degrees C, respectively. The optimum growth under varying salinity and temperature conditions was observed at 36 per thousand and 25 degrees C. Toxin content reached a peak of 376 fmol cell-1 at 25 degrees C and was lower (80-116 fmol cell-1) at higher temperatures (32-35 degrees C). Combined effects of salinity and temperature showed that P. bahamense was not able to grow at low salinity and temperature (i.e. below 26 per thousand-28 degrees C). Optimum growth was observed in higher salinities at all temperature conditions.


Assuntos
Dinoflagelados/crescimento & desenvolvimento , Dinoflagelados/patogenicidade , Toxinas Marinhas/biossíntese , Cloreto de Sódio/farmacologia , Animais , Meios de Cultura , Toxinas Marinhas/análise , Temperatura
16.
Toxicon ; 48(3): 239-45, 2006 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-16879849

RESUMO

We briefly report here the occurrence of toxic blooms in the eutrophic reservoir Billings, São Paulo city, Brazil. Water samples were collected in May 2004, during a cyanobacterial bloom. The presence of toxic species was confirmed by using PCR amplifications of a fragment region of genes encoding microcystin synthetase-mcyB. The determination of toxins was performed by liquid chromatography coupled with mass spectrometry (LC-MS). LC-MS analyses of the toxins from the bloom revealed variants of microcystins (MC), such as MC-LR, MC-RR and MC-YR. HPLC-FLD was used to determine the paralytic shellfish poisoning (PSP) saxitoxin (STX), neosaxitoxin (NEO), gonyautoxins 2 (GTX2) and 3 (GTX3). GTX2, GTX3 and NEO were detected for the first time in a natural sample from Billings reservoir. These results are a contribution to the knowledge of the biogeography of toxic cyanobacteria and their toxins, specifically in São Paulo.


Assuntos
Toxinas Bacterianas/análise , Cromatografia Líquida de Alta Pressão/métodos , Cianobactérias/isolamento & purificação , Espectrometria de Massas/métodos , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , Cianobactérias/genética , Cianobactérias/crescimento & desenvolvimento , Primers do DNA , Eletroforese em Gel de Ágar
19.
J Chromatogr A ; 994(1-2): 45-57, 2003 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-12779218

RESUMO

A liquid chromatography (LC)-based method with mass spectrometric (MS) detection was developed for simultaneous determination of various algal and cyanobacterial toxins extracted from phytoplankton occurring world-wide in marine waters and lakes. The method enables quantification of saxitoxin, anatoxin-A, domoic acid, nodularin, microcystins, okadaic acid and dinophysistoxin-1 with a single chromatographic run. In addition, the applied chromatographic conditions allow isolation and identification of substances suspected to be "new" microcystins (cyclic peptides) by fraction collection, hydrolysis, derivatisation of resulting free amino acids with the modified chiral Marfey's reagent N-alpha-(2,4-dinitro-5-fluorophenyl)-L-valinamide (L-FDVA) and enantioselective analysis of the amino acid derivatives by LC-ESI-MS.


Assuntos
Cromatografia Líquida/métodos , Cianobactérias/química , Eucariotos/química , Peptídeos Cíclicos/química , Fitoplâncton/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Água Doce , Microcistinas , Reprodutibilidade dos Testes , Água do Mar , Sensibilidade e Especificidade
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