Automatic MS/MS Data Mining Strategy for Rapid Screening of Polyether Toxins Derived from <i>Gambierdiscus</i> Species

<i>Gambierdiscus</i> is a primary producer of diverse polyether toxins that can biomagnify and transform within marine food webs, posing major risks to marine organisms and human health. Currently, many toxins derived from <i>Gambierdiscus</i> remain unidentified. Existing toxin analysis methodologies primarily rely on known toxins, limiting the representation of toxin diversity and complexity and potentially underestimating associated risks. Herein, we present a Toxin-Screening program for high-throughput screening of polyether compounds by analyzing MS² fragmentation patterns of detected ions and identifying Pacific Ocean ciguatoxins (P-CTXs) and gambierones through specific ion recognition. Using the Toxin-Screening program, eight P-CTXs purified from fish and <i>Gambierdiscus</i> spp., alongside two commercial gambierones standards, were successfully extracted from 5027 MS² spectra and annotated. This method was subsequently applied to profile polyether compounds in three <i>Gambierdiscus caribaeus</i> strains, revealing only ten polyether compounds shared among the strains, while strain-specific compounds dominated. All <i>G. caribaeus</i> strains were found to produce gambierone, with levels notably varying among the strains. Several polyether compounds containing one or two SO₃ groups suggest a potential novel toxin family that warrants further investigation.