Characterization of maitotoxin‐4 (MTX4) using electrospray positive mode ionization high‐resolution mass spectrometry and UV spectroscopy

Type Article
Date 2020-10
Language English
Author(s) Pisapia Francesco1, Sibat ManoellaORCID1, Watanabe Ryuichi2, Roullier Catherine3, Suzuki Toshiyuki2, Hess PhilippORCID1, Herrenknecht Christine3
Affiliation(s) 1 : Ifremer, DYNECO Rue de l'Île d'Yeu 44311 Nantes, France
2 : NRIFS, Japan Fisheries Research and Education Agency 2‐12‐4 Fukuura, Kanazawa‐ku Yokohama Kanagawa 236‐8648, Japan
3 : Université de Nantes, MMS EA2160, Faculté de Pharmacie 9 rue Bias, 44035 Nantes, France
Source Rapid Communications In Mass Spectrometry (0951-4198) (Wiley), 2020-10 , Vol. 34 , N. 19 , P. e8859 (12p.)
DOI 10.1002/rcm.8859
WOS© Times Cited 1
Abstract

Rationale

The dinoflagellate genera Gambierdiscus and Fukuyoa are producers of toxins responsible for Ciguatera Poisoning (CP). Although having very low oral potency, maitotoxins (MTXs) are very toxic following intraperitoneal injection and feeding studies have shown they may accumulate in fish muscle. To date, six MTX congeners have been described but two congeners (MTX2 and MTX4) have not yet been structurally elucidated. The aim of the present study was to further characterize MTX4.

Methods

Chemical analysis was performed using Liquid Chromatography coupled to a Diode Array Detector (DAD) and positive ionization mode High Resolution Mass Spectrometry (LC/HRMS) on partially purified extracts of G. excentricus (strain VGO792). HRMS/MS studies were also carried out to tentatively explain the fragmentation pathways of MTX and MTX4.

Results

The comparison of UV and HRMS (ESI+) spectra between MTX and MTX4 led us to propose the elemental formula of MTX4 (C157H241NO68S2, as unsalted molecule). The comparison of the theoretical and measured m/z values of the doubly charged ions of the isotopic profile in ESI+ were coherent with the proposed elemental formula of MTX4. The study of HRMS/MS spectra on the tri‐ammoniated adduct ([M–H+3NH4]2+) of both molecules gave additional information about structural features. The cleavage observed, probably located at C99–C100 in both MTX and MTX4, highlighted the same A‐side product ion shared by the two molecules.

Conclusion

All these investigations on the characterization of MTX4 contribute to highlighting that MTX4 belongs to the same structural family of MTXs. However to accomplish a complete structural elucidation of MTX4, NMR‐based study and LC/HRMSn investigation will have to be carried out.

Full Text
File Pages Size Access
Author's final draft 23 1 MB Open access
4 508 KB Access on demand
1 MB Access on demand
1 MB Access on demand
12 3 MB Access on demand
Top of the page

How to cite 

Pisapia Francesco, Sibat Manoella, Watanabe Ryuichi, Roullier Catherine, Suzuki Toshiyuki, Hess Philipp, Herrenknecht Christine (2020). Characterization of maitotoxin‐4 (MTX4) using electrospray positive mode ionization high‐resolution mass spectrometry and UV spectroscopy. Rapid Communications In Mass Spectrometry, 34(19), e8859 (12p.). Publisher's official version : https://doi.org/10.1002/rcm.8859 , Open Access version : https://archimer.ifremer.fr/doc/00633/74524/