Since 1989, Diarrhetic Shellfish Poisoning (DSP) toxins have shown to be the main phycotoxins implied in contamination of shellfish from the Adriatic Sea. While initially poisonings were exclusively due to okadaic acid (OA), the toxin profile has completely changed in the last years, and yessotoxin (YTX) and its analogues are now predominant. Interestingly, the composition and the relative abundance of YTXs in mussels harvested at the same location in different years vary seasonally and annually. This high variability posed urgently the need to set up analytical methods for the rapid, direct, and combined determination of most of the DSP toxins. The most common methods provide for derivatization of each toxin with an appropriate auxiliary reagent followed by HPLC-FLD analysis. Unfortunately, there is no reagent which fits all DSP toxins and, even within YTX class, the method is not reliable for detection of those derivatives which lack of a conjugated diene functionality in the molecule. The suitability of LC-ESI-MS technique to the sensitive, specific and direct detection of OA and all the YTXs isolated so far is here reported. The LC-MS method provided a detection limit of 70 pg for YTX in full scan mode and was applied to determine toxic profile of shellfish collected along Cesenatico coasts (Emilia Romagna, Italy) in various years. Along with known yessotoxins, the method allowed to highlight the presence of new analogues whose structures were deduced by means of MS/MS experiments. Thus, the reported LC-MS method represents a key potentiality for natural products chemists to discover new YTX analogues and provides a more comprehensive approach than HPLC-FLD methods currently in use.
Determination of Known and New Yessotoxins from Adriatic Shellfish by Liquid Chromatography-Mass Spectrometry / Dell'Aversano, Carmela; Ciminiello, Patrizia; Fattorusso, Ernesto; Forino, Martino; S., Magno. - (2002), pp. 55-55. (Intervento presentato al convegno Xth International Conference on Harmful Algae tenutosi a St. Pete Beach, Florida, USA nel October 21-25, 2002).