Structures of Azaspiracid Analogs, Azaspiracid-4 and Azaspiracid-5, Causative Toxins of Azaspiracid Poisoning in Europe

Abstract
Two new analogs of azaspiracid, azaspiracid-4 and azaspiracid-5, isolated from the mussel Mytilus edulis, involved in a newly emerged shellfish poisoning in Europe were determined to be 3-hydroxy-22-demethylazaspiracid and 23-hydroxy-22-demethylazaspiracid, respectively.