Domoic acid (DA) is a kainic acid–type neurotoxin that causes amnesic shellfish poisoning (ASP). It is produced by algae and accumulates in shellfish, sardines, and anchovies. When sea lions, otters, cetaceans, humans, and other predators eat contaminated animals, poisoning may result. Exposure to this compound affects the brain, causing seizures, delirium and possibly death.

History

There has been little use of domoic acid throughout history except for in Japan, where it has been used as an anthelmintic for centuries.

Domoic acid was first isolated in 1959 from a species of red algae, Chondria armata, in Japan, which is commonly referred to as in the Tokunoshima dialect, or . Poisonings in history have been rare, or undocumented; however, it is thought that the increase in human activities is resulting in an increasing frequency of harmful algal blooms along coastlines in recent years. In 2015, the North American Pacific coast was heavily impacted by an algal bloom, consisting predominantly of the domoic acid-producing pennate diatom, Pseudo-nitzschia. Consequently, elevated levels of domoic acid were measured in stranded marine mammals, prompting the closure of beaches and damaging razor clam, rock crab and Dungeness crab fisheries.

In 1961, seabirds attacked the Capitola area in California, and though it was never confirmed, it was later hypothesized that they were under the influence of domoic acid.

In 1987, in Prince Edward Island, Canada, there was a shellfish poisoning resulting in 3 deaths. Blue mussels (Mytilus edulis) contaminated with domoic acid were blamed.

Domoic acid has been suggested to have been involved in an incident which took place on June 22, 2006, when a California brown pelican flew through the windshield of a car on the Pacific Coast Highway.

On Friday, June 14, 2019, a teenager was attacked and injured by a sea lion that was alleged to be under the influence of domoic acid in Pismo Beach on the Central California coast.

Chemistry

General

Domoic acid is a structural analog of kainic acid, proline, and endogenous excitatory neurotransmitter glutamate. Ohfune and Tomita, who wanted to investigate its absolute stereochemistry, were the first and only to synthesize domoic acid in 1982.

In 2018, using growth conditions known to induce domoic acid production in Pseudo-nitzschia multiseries, transcriptome sequencing successfully identified candidate domoic acid biosynthesis genes responsible for the pyrrolidine core. These domoic acid biosynthesis genes, or 'Dab' enzymes were heterologously expressed, characterized, and annotated as dabA (terpene cyclase), dabB (hypothetical protein), dabC (α-ketoglutarate–dependent dioxygenase), and dabD (CYP450).[[File:Domoic_Acid_Biosynthesis.png|alt=|thumb|upright=4|Simplified domoic acid biosynthetic pathway, with all pertinent structures, enzymes, and cofactors listed as described by Brunson et al., in their article "Biosynthesis of the neurotoxin domoic acid in a bloom-forming diatom".

{| class="wikitable floatleft "

|+ Symptoms of domoic acid

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! Humans !! Animals

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| vomiting || head weaving

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| nausea || seizures

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| diarrhea and abdominal cramps<br>within 24 hours of ingestion || bulging eyes

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| headache || mucus from the mouth

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| dizziness || disorientation and aggressiveness

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| confusion, disorientation || death

|-

| loss of short-term memory ||

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| motor weakness ||

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| seizures ||

|-

| profuse respiratory secretions ||

|-

| cardiac arrhythmias ||

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| coma and possible death ||

|-

| colspan="2" |References for all, unless otherwise noted:

There is no known antidote available for domoic acid. Therefore, if poisoning occurs, it is advised to go quickly to a hospital. Cooking or freezing affected fish or shellfish tissue that are contaminated with domoic acid does not lessen the toxicity.

As a public health concern, the concentration of domoic acid in shellfish and shellfish parts at point of sale should not exceed the current permissible limit of 20&nbsp;mg/kg tissue. In addition, during processing shellfish, it is important to pay attention to environmental condition factors.

On August 18, 1961, in Capitola and Santa Cruz, California, there was an invasion of what people described as chaotic seabirds. These birds were believed to be under the influence of domoic acid, and it inspired a scene in Alfred Hitchcock's feature film The Birds.

In the Elementary Season 1 Episode 13 "The Red Team", domoic acid was used as a poison to mimic Alzheimer's.

In the TV show Bunk'd, domoic acid somehow combines with fog to create a chemical that causes people to lose memory or gain alter-egos when inhaled.

See also

  • Canadian Reference Materials
  • Pseudo-nitzschia
  • Quisqualic acid
  • Brevetoxin
  • Ciguatoxin
  • Okadaic acid
  • Saxitoxin
  • Maitotoxin

References