Ipomea genera contains more than 500 species, both of climbing plants or shrubs and belong to the family of Convolvulaceae. The beautiful funnel-shaped flower usually blooms in the morning, giving to the plant the generic name Morning Glory. Chemical studies confirmed the ethnobotanical research findings on the use of these plants in rituals as hallucinogens.
The alkaloids responsible for the psychotomimetic effects found in Morning glory plants belong to the class of ergot alkaloids and they include different compounds which are tryptophan-derived toxins. The identification of these secondary metabolites started in 1918 with the isolation of ergotamine by A. Stoll and the later collaboration with A. Hoffmann who performed the synthesis of novel compounds related to ergot alkaloids including methylergometrine and lysergic acid diethylamide (LSD) .
What is Ergot?
Ergot fungi are a group of ascomycetes belonging to the genus Claviceps. The most widely known fungus belonging to this genus is the Claviceps purpurea and it can develop on cereals or flowering grass as a parasite.
The infestation by fungal spores in the host plant happen in the ovary during fertilization. Ergot produces a fruiting structure called sclerotium producing alkaloids in high concentrations such as ergotamine among others. [1]
The development of the sclerotium on ears of corn or rye as a parasite can lead to serious concerns in terms of myco-intoxications, inducing serious adverse effects that have been known since Middle Ages with the name of ergotism. [2] The convulsive symptoms such as spasms and psychosis induced by long-term ergot poisoning and the incurrence of gangrene due to vasoconstriction are the main signs of ergot intoxication.
There is also a theory proposing that the Salem witchcraft of 1692 was caused by the symptoms of convulsive Ergot poisoning, which were considered as signs of demonic affliction by the community. [3] Ergot is a rich source of the precursor lysergic acid to synthesize Lysergic acid diethylamide (LSD): ergotamine.
What are Ergot Alkaloids?
Ergot alkaloids are well known for their effects at physiological level, that can be both beneficial in health care or detrimental for abuse if humans and animals are exposed to their toxicity. [1]
To make an example, even if ergot alkaloids caused ergotism afflictions, they were also used as ancient remedies to promote abortion and to stop maternal bleeding after childbirth, due to the effects on uterine contractions. Ergot alkaloids are 3,4-substituted indole derivatives with an essential structural element, the tetracyclic ergoline ring system that is variously substituted at C-8. [1]
Ergot alkaloids are often divided into 3 classes according to their structure:
- Clavines;
- Lysergic acid amides;
- Ergopeptides.
The effects of ergot alkaloids are linked to their agonist, partial agonist, and/or antagonistic effects at biogenic amine receptor sites. These have a complex effect on cardiovascular functions, suppress prolactin secretion and enhance uterine motility.
Moreover, their toxicity can result in:
- Vomiting;
- Decrease circulation;
- Gangrene;
- Nausea;
- Rapid and weak pulse;
- Coma (in extreme cases). [4]
More than 80 ergot alkaloids have been isolated. Among the most noteworthy ergot alkaloids there are:
- Lysergic acid;
- Ergonovine;
- Methylergonovine;
- Lergotrile;
- Ergotamine;
- Bromocriptine;
- Others.
Ergot Alkaloids and Morning Glory Flowers
Ergot alkaloids have been found also in higher dicotyledonous plants such as Morning Glories, including Ipomoea asarifolia and Turbina corymbosa, Ipomoea violacea, Argyreia nervosa (Hawaiian Baby Woodrose) species among others. [1] Recent researches sustain that during evolution these plants or a predecessor plant recruited a clavicipitaceous fungus forming a symbiosis. [1] And both the host plant and parasitic fungus benefited from this symbiosis.
The gene cluster encoding the enzymes of the ergot alkaloid pathway have been sequenced highlighting a conserved sequence in dicotyledonous plants that seems the result of an ecological optimization process forming compounds capable of protecting the plant and the fungus from predators, but also stabilizing their symbiotic interaction.
The alkaloids produced by the parasitic fungus do not remain in the fungal mycelium but are translocated via the fungus trichomes into their plant host. And this could explain why this class of alkaloids is produced in plants such as Morning glory.
Extraction of Ergot Alkaloids from Morning Glory Seeds
Many methods have been developed in order to highlight the presence of ergot alkaloids in plants infected by the Claviceps fungus. Nevertheless the techniques applied are generally laborious and time-consuming.
In order to successfully extract ergot alkaloids such as ergine (D-lysergic acid amide, LSA) and ergometrine from Morning glory seeds and evaluate the relative concentrations, various innovative methods have been compared. [5]
Three different advanced extraction methods were applied and evaluated to check the best suitability for ergot alkaloids extraction and determination:
- Microwave-assisted extraction (MAE);
- Ultrasound-assisted extraction in ultrasound bath (UAE-B);
- Sonotrode (UAE-S).
Among these techniques, UAE-B resulted as the best method for ergot alkaloid extraction. Thanks to ultrasonic waves the extraction time and the extraction efficiency are greatly improved compared to other methods. The solvent mixture used for extracting alkaloids included methanol and water and the whole process was optimized in order to perfectly tune extraction temperature, time and solvent mixture. [5]
Among the compounds found in different varieties of Morning glory seeds there are:
- Ergine;
- Ergometrine;
- Penniclavine;
- Chanoclavine;
- Lysergic acid hydroxyethylamide (LSH);
- Lysergol and their isomers.
Interestingly when a single seed was analyzed the relative abundance of the ergot alkaloids ergine and ergometrine vary greatly going from close to the limit of quantification (LOQ) to almost two times greater than the mean concentration. This can explain the serious risk of overdose or intoxication of people experimenting Morning glory seeds.
Compared to seeds, the concentration of ergot alkaloids in aereal plant samples appears to be 12-fold lower. It should be noticed that MAE extraction led to unexpectedly high ergine concentration compared to other methods. This is due most likely to the decay of analytes during the extraction procedure because of microwave energy.
Main Ergot Alkaloids
Ergine
This is the simplest of the ergot alkaloids. Ergine is also known as lysergic acid amide (LSA) and it has a similar structure of LSD. The psychotropic action is due to the interaction of the molecule with 5HT2A receptors, exerting a partial agonist action on them.
There is still a lack of information but it seems that ergine is the main serotonergic psychedelic contained in Morning glory seeds, nevertheless it seems that when extracted and isolated, ergine is only mildly psychoactive.
For this reason the hallucinogenic effect seems to be due to a mix of ergoline alkaloids.
Ergine can interact with serotonin, adrenergic and dopamine receptors, but has lower affinity to them compared to the synthetic counterpart LSD, that is definitively more potent.
The legal status of this molecule depends on the country.
The possession of the isolated compound is illegal both in USA and UK also because ergine is the precursor for the synthesis of LSD. Nevertheless the plant and seeds of Morning glory can be cultivated, sold and distributed.
Ergometrine
Ergometrine is also known as ergonovine. This compound has a medical use in obstetrics to cause uterus contractions or to stop post-partum bleeding. If the compound is administered orally it can cause vomiting and nausea.
Rarely hypertensive reactions and cardiac arrest have been described. Ergometrine leads to psychedelic effects at high doses and this can be due to the interaction with 5HT2A receptors. Because of possible precursors to synthesize LSD, this compound is listed in Table I of controlled substances.
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