| Abstract | In recent years the number of known marine algal toxins has increased tremendously, mainly by discovery of new analogues and metabolites within known toxin groups. This is due in particular to the use of LC-MS/MS. In this presentation, we will outline some new strategies based on various MS/MS scanning techniques that can be used for comprehensive detection and identification of new structural analogues of toxins. One example is the detection of assorted new analogues of the cyclic imine toxins, spirolides (SPX). Targeting key collision-induced product ions (m/z 150 or 164) in a precursor ion scanning mode and presenting the ion intensity data in a 2-D contour plot (m/z vs. retention time) allowed the detection of new toxins as individual 'spots' and also determines their masses. Product ion scans of those masses then allow detailed structure information to be generated. Thus, several new SPX analogues including fatty acid acyl ester metabolites have been identified. Examples will also be shown for the yessotoxin (YTX), okadaic acid (OA) and pectenotoxin (PTX) groups. The discovery of all these new toxin analogues raises some important questions such as their toxicological significance and whether we will be able to monitor for the toxins without standards. |
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