Synthesising a shellfish toxin
Dinoflagellates are microscopic plankton commonly known for causing algal blooms or red tides. Certain dinoflagellates produce neurotoxins called spirolides, which concentrate in shellfish that feed on them – these can poison people who subsequently eat the shellfish. Although spirolides are a health hazard, scientists know little about them due to limited supply of the toxin, which is extracted from the digestive glands of shellfish. To obtain sufficient quantities for studying the toxicity, the EU-funded SPIROSYNTH (Total synthesis of 13-desmethyl spirolide C) project aimed to create a spirolide toxin artificially. Since the spirolide's chemical structure is complex, researchers planned to synthesise it in two 'north' and 'south' parts and subsequently join the two fragments together. In turn, each north and south fragment had to be built up through step-wise chemical reactions using a skeleton of building blocks. By the project's end, chemists had created the entire south fragment and were finalising the north fragment before connecting them to complete the molecule. Since this will be the first time scientists have synthesised a complete spirolide, the techniques they developed will be useful for synthesising other organic compounds. Producing large quantities of the toxic spirolide will allow scientists to study its mode of action and understand its long-term effect on human health.
