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

Gambierdiscus 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 Gambierdiscus 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 Gambierdiscus 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 Gambierdiscus caribaeus strains, revealing only ten polyether compounds shared among the strains, while strain-specific compounds dominated. All G. caribaeus 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.