Screening of several Amphidinium species and strains for amphidinols and related secondary metabolites

The presented thesis successfully provided the missing knowledge about the tox-in profiles of every received sample strain by using the selected reaction monitor-ing method in an UHPLC-MS/MS instrument. Out of the 69 strains from eleven Amphidinium species, a total of 32 strains from six different species produced at least one amphidinol. During the quantification of the identified amphidinols the amount of toxin contained in a single cell, called cell quote, was calculated, which was crucial since Amphidinium species not only show hemolytic, cytotoxic and ichthyotoxic activities (Mooney et al., 2010), but were reported to create harmful algal blooms that can have devastating impacts on public health, fisheries re-sources, and coastal commodities (Díaz et al., 2019). A linkage between the calcu-lated cell quote in the amphidinols and the toxicity effects could be investigated in future bioassays. The stated hypothesis concerning the possibility to discover previously unknown amphidinol variations in the introduction of this work proved to be correct. The analysis of the complete sample set undertaken by the neutral loss and full scan methods resulted in 79 masses possibly containing amphidinol variations, that subsequently were examined about similarities to known amphidinols by using an enhanced product ion scan (EPI). Out of the 79 recorded EPI scans, eleven sub-stances were identified as possible new amphidinol variations based on their fragmentation spectrum. Finally, fragmentation pattern proposals were stated for every of the eleven unknown substances. Future works should implement the discovered amphidinol variations into the existing SRM method, and additionally quantify the discovered variations about their toxin profile and cell quote since the proposed fragmentation patterns were the last step completed in this thesis. Otherwise, the procedure for the discovery of new amphidinol variations proved to work well and can therefore be applied to new sample strains in upcoming projects