Domoic acid, a toxin produced by algae that can infest shellfish, is to blame for the recent spate of deaths from seafood poisoning, according to reports. The California Department of Health Services has detected elevated levels of domoic acid in sardines and mussels from coastal counties.
Domoic acid is synthesized by the microscopic alga, or diatom, Pseudo-nitzschia. Shellfish, including molluscs and crabs, ingest the algae, and so accumulate the toxin, ready to pass it on to some unsuspecting seafood diner. In large enough concentration, domoic acid causes amnesic shellfish poisoning. Symptoms occur within 24 hours and include vomiting, nausea, diarrhea and abdominal cramps. After a couple of days of such unpleasantness, short-term memory loss, dizziness, and confusion, can occur in severe cases as well as motor function problems, heart palpitations, and potentially coma and death.
Unfortunately, the toxin is not destroyed by cooking.
A total synthesis of domoic acid was carried out in 1982 by Yasufumi Ohfune and Masako Tomita of the Suntory Institute for Bioorganic Research, Japan, who corrected the initial structure report. (JACS, 1982, 104, 3511-3513).