Freshwater cyanobacterial harmful algal blooms (cHABs) have the capacity to form dangerous secondary metabolites known as cyanotoxins. These cyanotoxins can potentially cause neurotoxic, hepatoxic, cytotoxic, dermatoxic, cardiac, reproductive, and gastrointestinal effects. As cyanobacteria continue to be found more frequently in freshwater systems and drinking water reservoirs, they pose a threat to humans, animals, and ecosystems. With the overall goal to secure public health, it is important to develop a reliable analytical workflow that can quickly and accurately study the harmful effects of these cyanotoxins. Considering this, our goal is to develop a method that involves synthesis, characterization, analytical method development, and biological studies of synthetic cyanotoxins which would contribute significantly to research regarding cHABS.<br/><br/>Due to the lack of authentic standards, there is limited information that exists regarding the harmful effects of cyanotoxins. Isolating the natural product can be a very difficult and time-consuming task that does not ensure the product will be present in high concentration. Furthermore, isolation is not always attainable depending on the stability of the cyanopeptide or the bloom itself. To combat this issue, our solution is to use Solid-Phase Peptide Synthesis to create synthetic Anabaenopeptins, a specific class of cyanotoxins that are composed of a cyclic pentapeptide. After complete synthesis and purification, the synthetic material can be used as an alternative to the natural product to build standard curves that will serve to quantify specific anabaenopeptins in lake water samples. They can also be used to study the toxicity of anabaenopeptins. The methods displayed in the poster presentation will specifically focus on the synthesis of Anabaenopeptin I. This method includes the formation of a peptide chain using a Semi-Automated microwave and purification via High-Performance Liquid Chromatography. The overall synthesis presented very promising results. For instance, the desired mass of the target product was observed in the mass spectrum and the linear form of Anabaenopeptin I was successfully isolated. The isolated material was submitted to be tested on an oral cancer cell line via an MTT assay. This was observed to inhibit cell proliferation which provided valuable preliminary information regarding the toxicity of the synthetic Anabaenopeptin.

Synthesis and biological studies of contaminants released during harmful algal blooms

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.