ChemInform Abstract: Chemistry of the Peptidic Alkaloids of Ergot. Part 1. Classification and Chemistry of Ergopeptides

Komarova, E. L.; Толкачев, О. Н.

doi:10.1002/chin.200152281

Cited by 25 publications

(51 citation statements)

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“…Thus EAs are positively charged in acidic solutions and neutral at higher pH values. EAs are also light sensitive and degrade upon UVradiation (Rutschmann & Stadler 1978;Komarova & Tolkachev 2001b). Many EAs, including the most common, are naturally fluorescent (Komarova & Tolkachev 2001b;Flieger et al 1997).…”

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confidence: 99%

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Ergot alkaloids in rye flour determined by solid-phase cation-exchange and high-pressure liquid chromatography with fluorescence detection

Storm

Rasmussen

Strobel

et al. 2008

Food Additives & Contaminants: Part A

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alkaloids in rye flour determined by solid phase cation-exchange and high pressure liquid chromatography with fluorescence detection. Food Additives and Contaminants, 2008, 25 (03) Ergot alkaloids (EAs) are mycotoxins which are undesirable contaminants of cereal products, particularly rye. A method was developed employing clean-up by cation-exchange solid phase extraction, separation by HPLC under alkaline conditions and fluorescence detection. It is capable of separating and quantifying both C8-isomers of ergocornine, a-ergocryptine, ergocristine, ergonovine, and ergotamine. The average recovery was 61±10 % with limits of detection from 0.2 to 1.1 µg kg-1. Therty-four unknown rye flour samples from Danish mills contained on average 46 µg kg-1 with a maximum content of 234 µg kg-1. The most common ergot alkaloids were ergotamine and a-ergocryptine including their C8-isomers. 54 % of the ergot alkaloids were detected as C(8)-S isomers.

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confidence: 99%

“…These EAs are very similar differing only in substituents on C8 (Figure 1). An important feature of EAs containing a C9=C10 double bond is the rapid isomerisation at C8, especially in aqueous acidic or alkaline solutions (Hofmann 1964;Komarova & Tolkachev 2001b). The C8-(R)…”

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confidence: 99%

Ergot alkaloids in rye flour determined by solid-phase cation-exchange and high-pressure liquid chromatography with fluorescence detection

Storm

Rasmussen

Strobel

et al. 2008

Food Additives & Contaminants: Part A

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“…In contrast, to the dissimilar contribution of yields between the C 10 -stereoisomers of ergometrine, ergometrinine, the C 8 -stereoisomer of ergometrine, forms two different Fig. 1 Reaction scheme for hydroxylation of ergometrine at C 9 -C 10 -double bond 1 to 10-(S)-LEM 3 and 10-(R)-LEM 4 via formation of a carbenium ion 2 (Komarova and Tolkachev 2001) lumi compounds in comparable yields (20 and 37% for 10-(S)-and 10-(R)-lumi-ergometrinine, respectively) after exposure to UV-light in aqueous acidic solution (Hellberg 1957). For this surprising difference, no explanation has been given until now.…”

Section: Introductionmentioning

confidence: 87%

“…These toxins have been detected in cereals and various foodstuffs (Crews et al 2009;Klug et al 1988; Kokkonen and Jestoi 2010;Krska et al 2008;Müller et al 2006;Scott and Lawrence 1980;Scott et al 1992), and they undergo different degradation reactions (Komarova and Tolkachev 2001). One of these degradation products is formed by the addition of water to the C 9 -C 10 double bond of the ergoline skeleton-a uniform characteristic of all EAs.…”

Section: Introductionmentioning

confidence: 96%

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Lumi-ergometrine – structural identification and occurrence in sclerotia

et al. 2011

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The fungus Claviceps purpurea grows on grasses and cereal grains and produces six predominant ergot alkaloids. These toxic substances undergo different transformation reactions during storage and cereal processing. One of these reactions is the addition of water to a double bond in the ergoline skeleton. Since light is required for this process, the substances formed were named lumi-ergot alkaloids. From these, a new asymmetric carbon and consequently two epimers with different polarities are formed. For investigations of lumi-ergot alkaloids, ergometrine was used exemplarily as it represents one of the six ergot alkaloids predominantly formed by Claviceps purpurea. The main reaction product, the less polar compound of the two lumi-ergometrine epimers, was separated by HPLC and unambiguously identified as 10-(S)-lumi-ergometrine using X-ray structural analysis. A HPLC-MS/MS method was developed for the detection of this substance in sclerotia extracts. Using this method, the existence of both epimeric forms of lumi-ergometrine could be proved in the sclerotia. This is the first time that the existence of a lumi-transformation product of ergot alkaloids was proved in naturally grown samples.

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Permeability of ergot alkaloids across the blood‐brain barrier in vitro and influence on the barrier integrity

Mulac

Hüwel

Galla

et al. 2011

Molecular Nutrition Food Res

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ScopeErgot alkaloids are secondary metabolites of Claviceps spp. and they have been in the focus of research for many years. Experiments focusing on ergotamine as a former migraine drug referring to the ability to reach the brain revealed controversial results. The question to which extent ergot alkaloids are able to cross the blood-brain barrier is still not answered.Methods and resultsIn order to answer this question we have studied the ability of ergot alkaloids to penetrate the blood-brain barrier in a well established in vitro model system using primary porcine brain endothelial cells. It could clearly be demonstrated that ergot alkaloids are able to cross the blood-brain barrier in high quantities in only a few hours. We could further identify an active transport for ergometrine as a substrate for the BCRP/ABCG2 transporter. Investigations concerning barrier integrity properties have identified ergocristinine as a potent substance to accumulate in these cells ultimately leading to a weakened barrier function.ConclusionFor the first time we could show that the so far as biologically inactive described 8-(S) isomers of ergot alkaloids seem to have an influence on barrier integrity underlining the necessity for a risk assessment of ergot alkaloids in food and feed.

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ChemInform Abstract: Chemistry of the Peptidic Alkaloids of Ergot. Part 1. Classification and Chemistry of Ergopeptides

Cited by 25 publications

References 0 publications

Ergot alkaloids in rye flour determined by solid-phase cation-exchange and high-pressure liquid chromatography with fluorescence detection

Ergot alkaloids in rye flour determined by solid-phase cation-exchange and high-pressure liquid chromatography with fluorescence detection

Lumi-ergometrine – structural identification and occurrence in sclerotia

Permeability of ergot alkaloids across the blood‐brain barrier in vitro and influence on the barrier integrity

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