Ergot

• Ergot: fungi of the genus Claviceps. All Claviceps species are ergot. The most well-known member is Claviceps purpurea (Latin purpuro, purple, "to adorn/beautify"), the rye ergot fungus, which is parasitic on grasses and cereals (especially rye).
  • A Claviceps spore infects a flowering grass or cereal's floret. Upon connection to the vascular bundle, soft white sphacelia tissue develops. This hardens and dries into a sclerotium in the destroyed floret's husk.
  • Alkaloids and lipids accumulate in the sclerotium.
• Alkaloid: Basic (high-pH) naturally-occurring organic compounds containing nitrogen. The "true alkaloids" are biosynthesized from amino acids and contain nitrogen in a heterocycle (a cyclic structure containing more than one element).
  • Indole: The aromatic heterocycle C₈H₇N. Bicyclic pair of benzene (C₆H₆) and pyrrole (C₄H₄NH) sharing an edge. A biosynthetic precursor to the indole alkaloids, including the amino acid tryptophan and 3-indolepropionic acid (IPA).
  • Tryptophan: An essential amino acid (one which cannot be biosynthesized in humans), and a precursor in humans of serotonin, melatonin, and vitamin B3. Clostridium sporogenes in the human gut metabolizes tryptophan into indole.
  • Ergoline: the structural skeleton shared by ergoline alkaloids.

Ergoline path (the ergot alkaloids)

• L-Tryptophan -> (prenylation via DMAPP from mevalonic acid, catalyzed by DMATS)
• 4-L-DMAT -> (N-methylation via SAM, catalyzed by EasF)
• 4-DMA-L-abrine -> (decarboxylation+oxidation via EasC, catalyzed by EasE)
• Chanoclavine-I -> (oxidation via EasD)
• Chanoclavine-I-aldehyde (a D₂ dopamine receptor stimulant) ->
• Agroclavine ->
• Emiloclavine ->
• Paspalic acid ->
• Lysergic acid

Dry claviceps purpurea (and claviceps africana) sclerotium consist of about 2% ergot alkaloids by weight.