Structure and Biosynthesis of the Ergot Pigments

Franck, Burchard

doi:10.1002/anie.196902511

Cited by 35 publications

(26 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Potential candidates would include the ergochrome (secalonic acids) pigments produced by ergot of rye fungi. 16 These are not produced by fescue grass endophyte fungi nor is the hyperthermia induced by these fungi malignant.…”

Section: Discussionmentioning

confidence: 99%

Evidence that enforced sunlight exposure can cause hyperthermia in cattle ingesting low levels of ergot of rye (Claviceps purpurea), when air temperature and humidity conditions are only moderate

2003

Aust Veterinary J

View full text Add to dashboard Cite

Some sunlight exposed cattle, dosed with a low amount of ergot of rye, can experience a body temperature elevation above the normal range, even under mild ambient temperature and humidity conditions. Sunlight exposure causes an increase in body temperature in normal cattle that is probably attributable to solar radiant heat. Ergot ingestion causes an increase in body temperature in shaded cattle that is probably attributable to ambient temperature and humidity effects. This response can be increased by sun exposure and this increase is attributable to solar radiant heat effects and possibly also solar radiation. A response to radiant heat is consistent with the known physiological effects of ingested ergot alkaloids, but a response to solar radiation is not.

show abstract

Section: Discussionmentioning

confidence: 99%

Evidence that enforced sunlight exposure can cause hyperthermia in cattle ingesting low levels of ergot of rye (Claviceps purpurea), when air temperature and humidity conditions are only moderate

2003

Aust Veterinary J

View full text Add to dashboard Cite

show abstract

“…Our revised estimate of the alkaloid content of Bourke's sclerotia (Forbes sample, Table 2) is 1893 mg/kg, or 2715 mg/kg if epimers are included. However, this does not affect the conclusions drawn by Bourke (2003), that sunlight exposure appears to be a critical factor in a particularly lethal form of hyperthermia in cattle and sheep, and that toxins other than ergot alkaloids could be involved, such as the ergochromes (Franck 1969;Buchta and Cvak 1999). Further research is required to investigate the ergochrome content of Australian rye ergot sclerotia and to clarify the role they play in toxicity to livestock.…”

Section: Cases Of Ergotismmentioning

confidence: 97%

Alkaloids in Australian rye ergot (Claviceps purpurea) sclerotia: implications for food and stockfeed regulations

Blaney¹,

Molloy²,

Brock³

2009

Anim. Prod. Sci.

View full text Add to dashboard Cite

Rye ergot (Claviceps purpurea) occasionally causes toxicity (chiefly expressed as hyperthermia) in Australian livestock, either as a result of grazing infected annual (Lolium rigidum) and perennial (L. perenne) rye grasses, or if the ergot sclerotia produced in rye grasses contaminate grain crops used as stockfood. Alkaloids in 30 samples of Australian rye ergot sclerotia taken from rye grasses and grain screenings, and some feed samples contaminated with rye grass ergot sclerotia, were assayed by high performance liquid chromatography. Samples originated from across southern Australia. Ergotamine was the dominant alkaloid in all samples, followed by a-ergocryptine, ergocornine, ergosine and their respective -imine epimers. Ergotamine concentrations in sclerotia ranged up to 2257 mg/kg (as received basis). Ergocristine was a very minor component (<50 mg/kg) in all samples. Total alkaloids in freshly collected sclerotia ranged from 1003 to 3321 mg/kg (0.10 to 0.33%), and up to 3766 mg/kg with epimers included, although lower concentrations were found in samples stored for some time. Alkaloid profiles in sclerotia were all very similar, and concentrations did not appear to be related to size of sclerotia, source region, nor to the rye grass or grain from which they were taken. Previous cases of toxicity in livestock are reviewed and several new cases are reported. The implications of variable alkaloid contents of rye ergot sclerotia are discussed in terms of Australian food and stockfeed regulations.

show abstract

“…The yellow ergochromes are dimers of tetrahydroxanthone units [ 7 ]. Four different xanthone derivatives were described as ergochrome units in C. purpurea and all possible combinations of two of these units occur in nature [ 8 ]. Their concentration in the sclerotia is considerably higher (5 g/kg) than that of endocrocin and clavorubin (40 mg/kg) [ 8 ].…”

Section: Introductionmentioning

confidence: 99%

Identification and characterization of the ergochrome gene cluster in the plant pathogenic fungus Claviceps purpurea

Neubauer

Dopstadt

Humpf

et al. 2016

Fungal Biol Biotechnol

View full text Add to dashboard Cite

Background Claviceps purpurea is a phytopathogenic fungus infecting a broad range of grasses including economically important cereal crop plants. The infection cycle ends with the formation of the typical purple-black pigmented sclerotia containing the toxic ergot alkaloids. Besides these ergot alkaloids little is known about the secondary metabolism of the fungus. Red anthraquinone derivatives and yellow xanthone dimers (ergochromes) have been isolated from sclerotia and described as ergot pigments, but the corresponding gene cluster has remained unknown. Fungal pigments gain increasing interest for example as environmentally friendly alternatives to existing dyes. Furthermore, several pigments show biological activities and may have some pharmaceutical value.ResultsThis study identified the gene cluster responsible for the synthesis of the ergot pigments. Overexpression of the cluster-specific transcription factor led to activation of the gene cluster and to the production of several known ergot pigments. Knock out of the cluster key enzyme, a nonreducing polyketide synthase, clearly showed that this cluster is responsible for the production of red anthraquinones as well as yellow ergochromes. Furthermore, a tentative biosynthetic pathway for the ergot pigments is proposed. By changing the culture conditions, pigment production was activated in axenic culture so that high concentration of phosphate and low concentration of sucrose induced pigment syntheses.ConclusionsThis is the first functional analysis of a secondary metabolite gene cluster in the ergot fungus besides that for the classical ergot alkaloids. We demonstrated that this gene cluster is responsible for the typical purple-black color of the ergot sclerotia and showed that the red and yellow ergot pigments are products of the same biosynthetic pathway. Activation of the gene cluster in axenic culture opened up new possibilities for biotechnological applications like the dye production or the development of new pharmaceuticals.Electronic supplementary materialThe online version of this article (doi:10.1186/s40694-016-0020-z) contains supplementary material, which is available to authorized users.

show abstract

Structure and Biosynthesis of the Ergot Pigments

Cited by 35 publications

References 37 publications

Evidence that enforced sunlight exposure can cause hyperthermia in cattle ingesting low levels of ergot of rye (Claviceps purpurea), when air temperature and humidity conditions are only moderate

Evidence that enforced sunlight exposure can cause hyperthermia in cattle ingesting low levels of ergot of rye (Claviceps purpurea), when air temperature and humidity conditions are only moderate

Alkaloids in Australian rye ergot (Claviceps purpurea) sclerotia: implications for food and stockfeed regulations

Identification and characterization of the ergochrome gene cluster in the plant pathogenic fungus Claviceps purpurea

Contact Info

Product

Resources

About