Liquid Chromatography Coupled to High-Resolution Mass Spectrometry for the Confirmation of Caribbean Ciguatoxin-1 as the Main Toxin Responsible for Ciguatera Poisoning Caused by Fish from European Atlantic Coasts

Abstract

Ciguatera poisoning (CP) is a common seafood intoxication mainly caused by the consumption of fish contaminated by ciguatoxins. Recent studies showed that Caribbean ciguatoxin-1 (C-CTX1) is the main toxin causing CP through fish caught in the Northeast Atlantic, e.g., Canary Islands (Spain) and Madeira (Portugal). The use of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) combined with neuroblastoma cell assay (N2a) allowed the initial confirmation of the presence of C-CTX1 in contaminated fish samples from the abovementioned areas, nevertheless the lack of commercially available reference materials for these particular ciguatoxin (CTX) analogues has been a major limitation to progress research. The EuroCigua project allowed the preparation of C-CTX1 laboratory reference material (LRM) from fish species (Seriola fasciata) from the Madeira archipelago (Portugal). This reference material was used to implement a liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) for the detection of C-CTX1, acquisition of full-scan as well as collision-induced mass spectra of this particular analogue. Fragmentation pathways were proposed based on fragments obtained. The optimized LC-HRMS method was then applied to confirm C-CTX1 in fish (Bodianus scrofa) caught in the Selvagens Islands (Portugal).Key Contribution: LC-Q-TOF-MS in full-scan MS and MS/MS mode permitted successful acquisition of C-CTX1 spectra. Fragmentation pathways are presented. C-CTX1 was confirmed in a barred hogfish (Bodianus scrofa) from the Selvagens Islands (Portugal).

First Detection of Algal Caribbean Ciguatoxin in Amberjack Causing Ciguatera Poisoning in the Canary Islands (Spain)

“…C-CTX1 (0.46 ng/g) and 17-hydroxy-C-CTX1 (0.22 ng/g) were present in concentrations clearly above the guidance level proposed by the FDA for C-CTX1 (0.1 ng/g) [ 24 ]. These results match the data in the literature in which, not only in the endemic areas of the Caribbean Sea, but also in the east Atlantic Ocean, C-CTX1 is always the main toxin present in the fish samples [ 19 , 25 , 26 , 27 ]. The presence of 56-methoxy- metabolites could be related to the artificial methoxylation of the CTXs during sample pretreatment [ 28 ].…”

First Detection of Algal Caribbean Ciguatoxin in Amberjack Causing Ciguatera Poisoning in the Canary Islands (Spain)

“…C-CTX1 (0.46 ng/g) and 17-hydroxy-C-CTX1 (0.22 ng/g) were present in concentrations clearly above the guidance level proposed by the FDA for C-CTX1 (0.1 ng/g) [ 24 ]. These results match the data in the literature in which, not only in the endemic areas of the Caribbean Sea, but also in the east Atlantic Ocean, C-CTX1 is always the main toxin present in the fish samples [ 19 , 25 , 26 , 27 ]. The presence of 56-methoxy- metabolites could be related to the artificial methoxylation of the CTXs during sample pretreatment [ 28 ].…”

Preparation of Ciguatoxin Reference Materials from Canary Islands (Spain) and Madeira Archipelago (Portugal) Fish

“…7). These results are in agreement with those reported in [15,35] where most of the fragments resulted from the fragmentation at the termini of the molecule (Figure 7). 7).…”

“…On the other hand, most of the characteristic fragments m/z 253.1, m/z 209.1, m/z 191.1, and m/z 181.1 were detected at high collision energies (40, 35 & 50 eV) (Figure7). These results are in agreement with those reported in[15,35] where most of the fragments resulted from the fragmentation at the termini of the molecule (Figure7).The same RMR value was obtained for CTX1B and CTX3C. The mobile phase composition, which is considerably different at the compound's retention time, does not affect the RMR under these conditions.…”

Identification of New CTX Analogues in Fish from the Madeira and Selvagens Archipelagos by Neuro-2a CBA and LC-HRMS

“…In accordance with the literature [44][45][46][47]49], our data suggest that the Caribbean ciguatoxin-1 (C-CTX1) would be responsible for ciguatera in the Selvagens and Desertas Islands. We observed a similar CTX profile in comparison to previous studies.…”

First Detection of Algal Caribbean Ciguatoxin in Amberjack Causing Ciguatera Poisoning in the Canary Islands (Spain)

“…C-CTX1 (0.46 ng/g) and 17-hydroxy-C-CTX1 (0.22 ng/g) were present in concentrations clearly above the guidance level proposed by the FDA for C-CTX1 (0.1 ng/g) [ 24 ]. These results match the data in the literature in which, not only in the endemic areas of the Caribbean Sea, but also in the east Atlantic Ocean, C-CTX1 is always the main toxin present in the fish samples [ 19 , 25 , 26 , 27 ]. The presence of 56-methoxy- metabolites could be related to the artificial methoxylation of the CTXs during sample pretreatment [ 28 ].…”

Preparation of Ciguatoxin Reference Materials from Canary Islands (Spain) and Madeira Archipelago (Portugal) Fish

“…7). These results are in agreement with those reported in [15,35] where most of the fragments resulted from the fragmentation at the termini of the molecule (Figure 7). 7).…”

“…On the other hand, most of the characteristic fragments m/z 253.1, m/z 209.1, m/z 191.1, and m/z 181.1 were detected at high collision energies (40, 35 & 50 eV) (Figure7). These results are in agreement with those reported in[15,35] where most of the fragments resulted from the fragmentation at the termini of the molecule (Figure7).The same RMR value was obtained for CTX1B and CTX3C. The mobile phase composition, which is considerably different at the compound's retention time, does not affect the RMR under these conditions.…”

Identification of New CTX Analogues in Fish from the Madeira and Selvagens Archipelagos by Neuro-2a CBA and LC-HRMS

“…In accordance with the literature [44][45][46][47]49], our data suggest that the Caribbean ciguatoxin-1 (C-CTX1) would be responsible for ciguatera in the Selvagens and Desertas Islands. We observed a similar CTX profile in comparison to previous studies.…”

First Detection of Algal Caribbean Ciguatoxin in Amberjack Causing Ciguatera Poisoning in the Canary Islands (Spain)

“…C-CTX1 (0.46 ng/g) and 17-hydroxy-C-CTX1 (0.22 ng/g) were present in concentrations clearly above the guidance level proposed by the FDA for C-CTX1 (0.1 ng/g) [ 24 ]. These results match the data in the literature in which, not only in the endemic areas of the Caribbean Sea, but also in the east Atlantic Ocean, C-CTX1 is always the main toxin present in the fish samples [ 19 , 25 , 26 , 27 ]. The presence of 56-methoxy- metabolites could be related to the artificial methoxylation of the CTXs during sample pretreatment [ 28 ].…”

Preparation of Ciguatoxin Reference Materials from Canary Islands (Spain) and Madeira Archipelago (Portugal) Fish

“…7). These results are in agreement with those reported in [15,35] where most of the fragments resulted from the fragmentation at the termini of the molecule (Figure 7). 7).…”

“…On the other hand, most of the characteristic fragments m/z 253.1, m/z 209.1, m/z 191.1, and m/z 181.1 were detected at high collision energies (40, 35 & 50 eV) (Figure7). These results are in agreement with those reported in[15,35] where most of the fragments resulted from the fragmentation at the termini of the molecule (Figure7).The same RMR value was obtained for CTX1B and CTX3C. The mobile phase composition, which is considerably different at the compound's retention time, does not affect the RMR under these conditions.…”

Identification of New CTX Analogues in Fish from the Madeira and Selvagens Archipelagos by Neuro-2a CBA and LC-HRMS

“…In accordance with the literature [44][45][46][47]49], our data suggest that the Caribbean ciguatoxin-1 (C-CTX1) would be responsible for ciguatera in the Selvagens and Desertas Islands. We observed a similar CTX profile in comparison to previous studies.…”