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Ergot alkaloids produced by endophytic fungi of the genus Epichloë.

Guerre P - Toxins (Basel) (2015)

Bottom Line: The development of fungal endophytes of the genus Epichloë in grasses results in the production of different groups of alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably.Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot alkaloids include the "sleepy grass" and "drunken horse grass" diseases.In the final section, interactions between ergot alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity.

View Article: PubMed Central - PubMed

Affiliation: Département des Sciences Biologiques et Fonctionnelles, Université de Toulouse, INP, ENVT, UR Mycotoxicologie, F-31076 Toulouse, France. p.guerre@envt.fr.

ABSTRACT
The development of fungal endophytes of the genus Epichloë in grasses results in the production of different groups of alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably. Ergot alkaloids, when present in endophyte-infected tall fescue, are responsible for "fescue toxicosis" in livestock, whereas indole-diterpene alkaloids, when present in endophyte-infected ryegrass, are responsible for "ryegrass staggers". In contrast, peramine and loline alkaloids are deterrent and/or toxic to insects. Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot alkaloids include the "sleepy grass" and "drunken horse grass" diseases. Although ergovaline is the main ergopeptine alkaloid produced in endophyte-infected tall fescue and is recognized as responsible for fescue toxicosis, a number of questions still exist concerning the profile of alkaloid production in tall fescue and the worldwide distribution of tall fescue toxicosis. The purpose of this review is to present ergot alkaloids produced in endophyte-infected grass, the factors of variation of their level in plants, and the diseases observed in the mammalian species as relate to the profiles of alkaloid production. In the final section, interactions between ergot alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity.

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Ergot alkaloids produced by endophytic fungi of the genus Epichloë in infected plants (adapted from Shardl et al. [70]. Copyright 2006, Elsevier). Ergotamine, ergosine, ergocornine, ergocryptine and ergocristine are additional ergopeptines commonly found in ergots of Claviceps purpurea but not Epichloë species.
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toxins-07-00773-f001: Ergot alkaloids produced by endophytic fungi of the genus Epichloë in infected plants (adapted from Shardl et al. [70]. Copyright 2006, Elsevier). Ergotamine, ergosine, ergocornine, ergocryptine and ergocristine are additional ergopeptines commonly found in ergots of Claviceps purpurea but not Epichloë species.

Mentions: Biosynthetic pathways and genes for ergot alkaloid synthesis in Epichloë species have been extensively reviewed in [70,71]. Synthesis of ergot alkaloids begins by the prenylation of l-tryptophan to obtain dimethylallyltryptophan (Figure 1). N-methylation and C-oxidation of dimethylallyltryptophan followed by intramolecular rearrangement leads to chanoclavine (1), which can be measured in endophyte-infected Achnatherum robustum and has weak binding properties to the dopamine receptors in the brain and no pharmacological effects [19,39,72]. Oxidoreduction of chanoclavine is necessary to obtain agroclavine (2). This compound has antimicrobial and cytostatic properties and is a weak dopaminergic agonist [73,74]. Oxidation of agroclavine leads to the formation of elymoclavine, which is more potent than agroclavine in the prolactin reduction assay [73], and then oxidation of elymoclavine leads to d-lysergic acid (3). d-lysergic acid has been identified in different endophyte-infected plants and in animals fed with endophyte-infected plants [75,76,77]. However, in contrast to observations made on other ergot alkaloids, this compound presented low vasoconstrictor properties in the saphenous vein bioassay and in the right ruminal artery and vein bioassay [78,79,80]. Different amide derivatives of d-lysergic acid (ergopeptines) have been characterized in endophyte-infected plants. Simple amide derivatives are ergoamides whereas more complex derivatives obtained with amino acids are ergopeptines.


Ergot alkaloids produced by endophytic fungi of the genus Epichloë.

Guerre P - Toxins (Basel) (2015)

Ergot alkaloids produced by endophytic fungi of the genus Epichloë in infected plants (adapted from Shardl et al. [70]. Copyright 2006, Elsevier). Ergotamine, ergosine, ergocornine, ergocryptine and ergocristine are additional ergopeptines commonly found in ergots of Claviceps purpurea but not Epichloë species.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4379524&req=5

toxins-07-00773-f001: Ergot alkaloids produced by endophytic fungi of the genus Epichloë in infected plants (adapted from Shardl et al. [70]. Copyright 2006, Elsevier). Ergotamine, ergosine, ergocornine, ergocryptine and ergocristine are additional ergopeptines commonly found in ergots of Claviceps purpurea but not Epichloë species.
Mentions: Biosynthetic pathways and genes for ergot alkaloid synthesis in Epichloë species have been extensively reviewed in [70,71]. Synthesis of ergot alkaloids begins by the prenylation of l-tryptophan to obtain dimethylallyltryptophan (Figure 1). N-methylation and C-oxidation of dimethylallyltryptophan followed by intramolecular rearrangement leads to chanoclavine (1), which can be measured in endophyte-infected Achnatherum robustum and has weak binding properties to the dopamine receptors in the brain and no pharmacological effects [19,39,72]. Oxidoreduction of chanoclavine is necessary to obtain agroclavine (2). This compound has antimicrobial and cytostatic properties and is a weak dopaminergic agonist [73,74]. Oxidation of agroclavine leads to the formation of elymoclavine, which is more potent than agroclavine in the prolactin reduction assay [73], and then oxidation of elymoclavine leads to d-lysergic acid (3). d-lysergic acid has been identified in different endophyte-infected plants and in animals fed with endophyte-infected plants [75,76,77]. However, in contrast to observations made on other ergot alkaloids, this compound presented low vasoconstrictor properties in the saphenous vein bioassay and in the right ruminal artery and vein bioassay [78,79,80]. Different amide derivatives of d-lysergic acid (ergopeptines) have been characterized in endophyte-infected plants. Simple amide derivatives are ergoamides whereas more complex derivatives obtained with amino acids are ergopeptines.

Bottom Line: The development of fungal endophytes of the genus Epichloë in grasses results in the production of different groups of alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably.Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot alkaloids include the "sleepy grass" and "drunken horse grass" diseases.In the final section, interactions between ergot alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity.

View Article: PubMed Central - PubMed

Affiliation: Département des Sciences Biologiques et Fonctionnelles, Université de Toulouse, INP, ENVT, UR Mycotoxicologie, F-31076 Toulouse, France. p.guerre@envt.fr.

ABSTRACT
The development of fungal endophytes of the genus Epichloë in grasses results in the production of different groups of alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably. Ergot alkaloids, when present in endophyte-infected tall fescue, are responsible for "fescue toxicosis" in livestock, whereas indole-diterpene alkaloids, when present in endophyte-infected ryegrass, are responsible for "ryegrass staggers". In contrast, peramine and loline alkaloids are deterrent and/or toxic to insects. Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot alkaloids include the "sleepy grass" and "drunken horse grass" diseases. Although ergovaline is the main ergopeptine alkaloid produced in endophyte-infected tall fescue and is recognized as responsible for fescue toxicosis, a number of questions still exist concerning the profile of alkaloid production in tall fescue and the worldwide distribution of tall fescue toxicosis. The purpose of this review is to present ergot alkaloids produced in endophyte-infected grass, the factors of variation of their level in plants, and the diseases observed in the mammalian species as relate to the profiles of alkaloid production. In the final section, interactions between ergot alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity.

Show MeSH
Related in: MedlinePlus