AskDefine | Define ergotamine

Dictionary Definition

ergotamine n : an alkaloid derived from ergot that is less toxic than ergot; causes constriction of blood vessels and is used to treat migraine

User Contributed Dictionary

English

Etymology

From Ergotamin, corresponding to ergot + amine.

Pronunciation

  • /ɜːˈgɒtəmiːn/

Noun

  1. In the context of "organic chemistry|biochemistry|pharmaceutical drug": An alkaloid, extracted from ergot, that causes constriction of blood vessels and has been used to treat migraine; it is related to lysergic acid.

Translations

an alkaloid extracted from ergot
  • Finnish: ergotamiini

Extensive Definition

Ergotamine is an ergopeptine and part of the ergot family of alkaloids; it is structurally and biochemically closely related to ergoline. It possesses structural similarity to several neurotransmitters, and has biological activity as a vasoconstrictor. It is used medicinally for migraine prevention and treatment of acute attacks (sometimes in combination with caffeine to increase absorption), and to induce childbirth and prevent post-partum haemorrhage. It was first isolated from the ergot fungus by Arthur Stoll at Sandoz in 1918 and marketed as Gynergen in 1921.

Mechanism of action

The mechanism of action of ergotamine is complex. The molecule shares similarity with neurotransmitters such as serotonin, dopamine, and adrenaline and can thus bind to several cell receptors acting both as agonist and antagonist in signal transduction within cellular tissues. The anti-migraine effect is due to constriction of the intercranial extracerebral blood vessels through the 5-HT1B receptor, and by inhibiting trigeminal neurotransmission by 5-HT1D receptors. Ergotamine also has effects on the dopamine and noradrenaline receptors. It is its action on the D2 dopamine and 5-HT1A receptors that can cause some side effects.

Biosynthesis

Ergotamine is a secondary metabolite (natural product) and the principal alkaloid produced by the ergot fungus, Claviceps purpurea, and related fungi in the family Clavicipitaceae. Its biosynthesis in these fungi requires the amino acid L-tryptophan and dimethylallyl diphosphate. These precursor compounds are the substrates for the enzyme, dimethylally-tryptophan (DMAT) synthase, catalyzing the first step in ergot alkaloid biosynthesis, i.e., the prenylation of L-tryptophan. Further reactions, involving methyltransferase and oxygenase enzymes, yield the ergoline, lysergic acid. Lysergic acid (LA) is the substrate of lysergyl peptide synthetase, a nonribosomal peptide synthetase, which covalently links LA to the amino acids, L-alanine, L-proline, and L-phenylalanine. Enzyme-catalyzed or spontaneous cyclizations, oxygenations/oxidations, and isomerizations at selected residues precede, and give rise to, formation of ergotamine.

Drug uses

Ergotamine is also a precursor of LSD, lysergic acid diethylamide.

See also

References

ergotamine in Danish: Ergotamin
ergotamine in German: Ergotamin
ergotamine in Spanish: Ergotamina
ergotamine in French: Ergotamine
ergotamine in Dutch: Ergotamine
ergotamine in Polish: Ergotamina
ergotamine in Swedish: Ergotamin
Privacy Policy, About Us, Terms and Conditions, Contact Us
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2
Material from Wikipedia, Wiktionary, Dict
Valid HTML 4.01 Strict, Valid CSS Level 2.1