Chemical Properties
Off-White Solid
Uses
Labelled Domoic Acid. Domoic Acid is an excitatory amino acid isolated from the red alga Chondria armata Okamura, Rhodomelaceae. Domoic acid shown to be responsible for amnesic shellfish poisoning ass
ociated with ingestion of certain cultured blue mussels. Domoic Acid is a structural analog of Kainic acid (K135000).
Definition
ChEBI: A L-proline derivative that is L-proline substituted by a carboxymethyl group at position 3 and a 6-carboxyhepta-2,4-dien-2-yl group at position 4. It is an analog of kainic acid and is the neurotoxin associated with the a
nesic shellfish poisoning (ASP).
General Description
Domoic acid, a heterocyclic amino acid neurotoxin is synthesized by various marine algaes. It possess some structural similarity to kainic acid.
Biological Activity
More potent and possibly more selective than kainate at kainate receptors, as demonstrated in electrophysiological studies.
Biochem/physiol Actions
Domoic acid is a potent agonist at receptors for excitatory amino acids glutamate and kainate. It has highest affinity for AMPA/kainate receptor of any kainate agonist. It can causes excessive excitation of neurons leading to depletion of energy stores.
Synthesis
A method using marine diatom symbiotic bacteria fermentation:
1) Strain activation.
2) Seed culture preparation: medium sterilization, inoculation, and aerobic cultivation.
3) Fermentation: inoculating the seed culture into fermentation medium u
Purification Methods
Domoic acid (~300 mg) is purifed on a Dowex1 column (3.5 x 40 mm, 200-400 mesh, acetate form), washed with H2O until neutral, then eluted with increasing concentrations of AcOH (8L) from 0 to 0.25M. The fraction containing domoic acid (in 50mL) is collected, evaporated to dryness under reduced pressure and recrystallised from aqueous EtOH. It is a glutamate and a Kainate receptor agonist. [Impellizzeri et al. Phytochemistry 14 1549 1975, Takemoto & Diago Arch Pharm 293 627 1960, Beilstein 22/4 V 371.]
