Introduction:
Ergot is an alkaloid containing dried sclerotium of a fungus, containing mainly indole alkaloids called ergolines. It is traditionally used to labour to assist delivery (oxytocic) and to reduce post-partum haemorrhage. The pharmacognosy of ergot of rye is discussed below.
Ergot / Argot or St. Anthony’s Fire
| Biological Source | Ergot is the dried sclerotium of a fungus, Claviceps puprea, arising in the ovary of the rye, Secale cereale. |
| Family | The fungus belongs to family Clavicipitaceae and the rye-plant belongs to the family Graminae. |
| Geographical Source | Germany and Switzerland, substitutes found in France, Algeria, USA and Canada. |
| Morphology/Macroscopical Characters | The sclerotia is hard, violet, characteristic odor with an unpleasant taste. |
| Microscopic Characters | Shows an outer zone of purplish-brown rectangular cells while the pseudoparenchyma consists of oval and rounded cells with fixed oil and protein. |
| Chemistry | The ergot alkaloids (ergolines) are indole alkaloids and can be divided into two classes:
1) The clavine-type alkaloids, which are derivatives of 6,8-dimethylergoline 2) The lysergic acid derivatives: a) Water soluble ones such as ergometrine and (b) Water insoluble ones such as ergotamine.  Ergotamine - An indole alkaloid obtained from the Ergot |
| Chemical Tests | 1. gives a blue colour with Van Curk’s reagent (para dimethylamino benzaldehyde)
2. gives blue fluorescence in water 3. when treated with ether, H2SO4 followed by sodium bicarbonate, aqueous layer shows a red violet colour 4. ergotamine + glacial acetic acid + ethyl acetate + H2SO4 gives a blue solution with a red tinge. When further treated with FeCl3 the blue colour disappears 5. powdered ergot when treate with NaOH solution develops a strong odor of trimethylamine. |
| Adulterants/Allied drugs/ Substitutes | Substitutes: Ergot of wheat, Ergot of barley, Ergot of oats, and Ergot of diss. |
| Uses | Ergometrine is used as an oxytocic drug to assist in labor and delivery and reduce post-partum haemorrhage. Ergotamine is used as an analgesic for treatment of migraines. Lysergic acid diethylamide (LSD-25) is a semi-synthetic preparation of lysergic aci with potent pyschotomimetic activity. |
| Other Notes (life cycle, extraction etc.) | Life Cycle:
1) Sexual Stage: The ascospores infect the ovary of the rye plant & if conditions are favourable it develops hyphal strands. It forms a white mass over the ovary known as the mycelium. 2) Asexual Stage: The hyphal strands further develop invading the ovary & converting it to a hard violet schlerotium. Schlerotium contains stromatum which shows a globular stalk. It encloses bag like structures known as ascus containing ascospores. If these ascospores are liberated they infect another rye plant. |
References:
- Evans, W. C. Trease and Evans Pharmacognosy, 16th ed.; Elsevier: New York, 2009.
- Kokate, C. K.; Gokhale, S. B.; Purohit, A. P. A textbook of Pharmacognosy, 29th ed.; Nirali Prakashan: Pune, 2009.
- Wikipedia – Ergotamine for the chemical structure: http://en.wikipedia.org/wiki/Ergotamine (accessed December 30, 2011).
