Ergot alkaloids in some rye-based UK cereal products

Alkaloids in food: a review of toxicity, analytical methods, occurrence and risk assessments

Alkaloids have been utilized by humans for years. They have diverse applications in pharmaceuticals. They have been proven to be effective in treating a number of diseases. They also form an important part of regular human diets, as they are present in food items, food supplements, diet ingredients and food contaminants. Despite their obvious importance, these alkaloids are toxic to humans. Their toxicity is dependent on a range of factors, such as specific dosage, exposure time and individual properties. Mild toxic effects include nausea, itching and vomiting while chronic effects include paralysis, teratogenicity and death. This review summarizes the published studies on the toxicity, analytical methods, occurrence and risk assessments of six major alkaloid groups that are present in food, namely, ergot, glycoalkaloids, purine, pyrrolizidine, quinolizidine and tropane alkaloids.

Occurrence of Ergot Alkaloids in Barley and Wheat from Algeria

The natural occurrence of six major ergot alkaloids, ergometrine, ergosine, ergotamine, ergocornine, ergokryptine and ergocristine, as well as their corresponding epimers, were investigated in 60 cereal samples (barley and wheat) from Algeria. Ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) and a QuEChERS extraction method were used for sample analysis. The results revealed that 12 out of 60 samples (20%) were contaminated with ergot alkaloids. Wheat was the most contaminated matrix, with an incidence of 26.7% (8 out of 30 samples). The concentration of total ergot alkaloids ranged from 17.8 to 53.9 µg/kg for barley and from 3.66 to 76.0 μg/kg for wheat samples. Ergosine, ergokryptine and ergocristine showed the highest incidences in wheat, while ergometrine was the most common ergot in barley.

Ergot and Ergot Alkaloids in Cereal Grains Intended for Animal Feeding Collected in Slovenia: Occurrence, Pattern and Correlations

This four-year study reports the occurrence of ergot alkaloids (EAs) in cereals intended for animal feeding collected in Slovenia. A total of 517 samples of cereals were analysed using liquid chromatography-tandem mass spectrometry for the presence of EAs. The sample set included wheat, rye, triticale, oat, spelt and barley. The study revealed that 17% of the analysed cereal samples were contaminated with at least one ergot alkaloid. EAs have two epimeric forms: -ine and -inine. The incidence rates of the -ine and -inine forms in the analysed samples were 16% and 15%, respectively. The highest contamination rates were observed in rye (54%), oat (50%) and spelt (30%), where the highest mean concentrations of total EAs were also determined (502 µg/kg, 594 µg/kg and 715 µg/kg, respectively). However, the highest concentrations of total EAs were found in wheat and rye (4217 µg/kg and 4114 µg/kg, respectively). The predominant EAs were ergometrine, ergosine and ergocristinine. The occurrence of six or more ergot alkaloids was observed in 49% of the positive samples. A weak correlation (p = 0.284) in the positive samples was found between the mass of sclerotia and the total concentrations of EAs using the Spearman correlation coefficient.

Simultaneous quantification of ergot and tropane alkaloids in bread in the Netherlands by LC-MS/MS

Atropine and scopolamine are tropane alkaloids (TAs), which are regulated for cereal-based foods for children in the EU. For ergot alkaloids (EAs) in cereals and cereal-based food harmonised legislation is not yet established. A fast and straightforward method, which employs extraction by acidified water/methanol followed by ultra-filtration prior to analysis by LC-MS/MS, was validated in bread for 20 EAs and six TAs. LOQs for individual alkaloids ranged from 0.3 to 1.2 µg kg^-1, while recoveries ranged from 65% to 94% and repeatability from 3.4% to 17%. A survey was conducted in the Netherlands on 40 retail samples of bread (wheat, rye, wheat-rye, multi-grain) collected in 2014 and 2018. TAs, including atropine and scopolamine, were not detected. Eighteen different EAs were detected and total levels varied between <LOQ and 335 µg kg^-1. Since EAs were detected in a wide concentration range, it is recommended to monitor their occurrence in bread more regularly.

Ergot Alkaloids in Wheat and Rye Derived Products in Italy

Genus Claviceps is a plant pathogen able to produce a group of toxins, ergot alkaloids (EAs), whose effects have been known since the Middle Ages (ergotism). Claviceps purpurea is the most important representative specie, known to infect more than 400 monocotyledonous plants including economically important cereal grains (e.g., rye, wheat, triticale). EAs are not regulated as such. Maximum limits are in the pipeline of the EU Commission while at present ergot sclerotia content is set by the Regulation (EC) No. 1881/2006 in unprocessed cereals (0.05% as a maximum). This study aimed to investigate the presence of the six principal EAs (ergometrine, ergosine, ergocornine, α-ergocryptine, ergotamine and ergocristine) and their relative epimers (-inine forms) in rye- and wheat-based products. Of the samples, 85% resulted positive for at least one of the EAs. Wheat bread was the product with the highest number of positivity (56%), followed by wheat flour (26%). Rye and wheat bread samples showed the highest values when the sum of the EAs was considered, and durum wheat bread was the more contaminated sample (1142.6 μg/kg). These results suggest that ongoing monitoring of EAs in food products is critical until maximum limits are set.

Links Between Genetic Groups, Host Specificity, and Ergot-Alkaloid Profiles within Claviceps purpurea (Fr.) Tul. on Slovenian Grasses

In the present study, the genetic relationships and ergot-alkaloid production of the fungus Claviceps purpurea on grasses were investigated, to determine any associations between grass host specificity, ergot-alkaloid production, and geographic origin. C. purpurea sclerotia were obtained from wild and cultivated grasses along a 300-km climatic gradient, from sub-Mediterranean to continental climates. Twenty-one infected grass samples provided 39 sclerotia for analysis of the ergot alkaloids ergometrine, ergosine, ergotamine, ergocornine, ergocryptine, and ergocristine, and their "-inine" epimers, using liquid chromatography-tandem mass spectrometry. C. purpurea ribosomal DNA underwent molecular classification to determine any grass host or geographic specificity of ergot-alkaloid composition for the different operational taxonomic units. Molecular analysis of sclerotia ribosomal DNA showed three genetic groups, with some associations with specific grass host taxonomic groups. The ergot-alkaloid composition data were in agreement with the data obtained by molecular methods. The most frequent ergot-alkaloid epimers were ergocristine, and ergosine. The total ergot-alkaloid concentrations in sclerotia varied from 59 to 4,200 mg kg^-1, which corresponds to 0.059 to 4.2 mg kg^-1 in animal feed (assuming ergot alkaloids at 1,000 mg kg^-1 sclerotia). Therefore, grasses can be associated with significant levels of ergot alkaloids. In addition, the ergot-alkaloid compositions of C. purpurea sclerotia can be different for infections with different C. purpurea genetic groups, because these show different ergot-alkaloid compositions.

Occurrence of ergot alkaloids in wheat from Albania

The occurrence of ergot alkaloids in wheat harvested in Albania was investigated. A total of 71 samples of winter wheat collected in 2014 and 2015 were analysed for the 12 most important ergot alkaloids using liquid chromatography-tandem mass spectrometry. In the harvesting year 2014, 48.6% of samples were contaminated with ergot alkaloids, whereas in 2015 only 19.4% of samples were contaminated. In 2014, the concentrations of total ergot alkaloids ranged from 17.3 to 975.4 μg kg^-1, and in 2015 they ranged from 10.3 to 390.5 μg kg^-1. The samples contained from one to nine ergot alkaloids. The most frequent were ergometrine, ergosine and ergocristine, and the least frequent were ergocryptine, ergocryptinine and ergocorninine.

Simultaneous Determination of 25 Ergot Alkaloids in Cereal Samples by Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry

A liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of 25 ergot alkaloids in cereal samples. The analytes included both -ine and -inine ergot alkaloids and were extracted using an acetonitrile and ammonium carbonate solution, followed by purification with C-18 sorbent. After full separation on a C18 column, the 25 ergot alkaloids were detected by LC-MS/MS using multiple reaction monitoring (MRM) in the positive ion mode. The linear range was 0.05-5.0 μg/kg for the 25 ergot alkaloids. The mean recoveries at three spiked concentrations varied from 76.5 to 120% with RSD < 15%. This method was validated using a FAPAS proficiency test sample of ergot alkaloids in rye flour and was finally applied to analyze real samples, including rye flours, wheat flours, whole wheat flours, bread, and noodles.

A mycotoxin-dedicated total diet study in the Netherlands in 2013: Part II – occurrence

The occurrence of 59 natural toxins was determined in 88 composite food and drink samples of a mycotoxin-dedicated total diet study performed in the Netherlands in 2013. Composite food samples were prepared by pooling foods from a food category (as consumed, e.g. peeled, cooked, etc.) according to their consumption by population groups in the Netherlands. A multi-targeted method based on QuEChERs extraction, dilute and shoot and analysis by liquid chromatography-tandem mass spectrometry was applied to the 88 composite samples. Dedicated methods with lower detection limits for patulin, aflatoxins and trichothecenes were also applied to specific food types. Thirty samples (34%) were positive for one or more mycotoxins. Patulin, aflatoxin M1, zearalenone and plant toxins, with the exception of scopolamine in liquorice, were not detected in any of the composite samples. Aflatoxin B1 was only detected, but not at quantifiable levels, in the composites that contained peanuts. Fumonisin B1 was only found at 18 μg/kg in breakfast cereals consumed by the population group of 7-69 years, whereas ochratoxin A occurred at low levels around 1 μg/kg in liquorice, legumes and coffee. Grains and grain-based food composites were positive for ergot alkaloids, enniatins B and B1 and deoxynivalenol (DON). The levels of DON in the positive samples were lower compared to other studies, with the exception of breakfast cereals for infants with a DON concentration of 116 μg/kg. This specific composite sample may have contained an ingredient with a concentration exceeding the maximum legal limit of 200 μg/kg. Alternaria toxins (alternariol and alternariol methyl ether) were detected at levels ranging from 1.0 to 8.9 μg/kg in a number of composite samples, including tomato products, nuts, cereal products, chocolate and wine. Mycophenolic acid and roquefortine C cooccurred in mould-ripened cheese composites, while mycophenolic acid also was found in dried fruit and liquorice composite samples.

An integrated targeted and untargeted approach for the analysis of ergot alkaloids in cereals using UHPLC – hybrid quadrupole time-of-flight mass spectrometry

An ultra-high performance liquid chromatography hybrid quadrupole – time of flight (Q-TOF) mass spectrometry (MS) method is described for the simultaneous quantitative determination of common ergot alkaloids and the screening, detection and identification of unexpected (less studied or novel) members of this class of toxic fungal secondary metabolites. The employed analytical strategy involves an untargeted data acquisition (consisting of full scan TOF MS survey and information dependent acquisition MS/MS scans) and the processing of data using both targeted and untargeted approaches. Method performance characteristics for the quantitative analysis of 6 common ergot alkaloids i.e. ergometrine, ergosine, ergotamine, ergocornine, ergocristine, ergokryptine and their corresponding epimers in rye were comparable to those previously reported for triple-quadrupole (QqQ) MS/MS. The method limits of quantification (LOQ) were in the range from 3 to 19 μg/kg, and good linearity was observed for the different ergot alkaloids in the range from LOQ to 1000 μg/kg. Furthermore, the method demonstrated good precision (relative standard deviations at 50 μg/kg not higher than 14.6 and 16.2% for the intra-day and inter-day precision, respectively), and the trueness values at different concentration levels were all between 89 and 115%. The method was applied for the analysis of a set of 17 rye samples and demonstrated the presence of these ergot alkaloids in the range from <LOQ to 2,811 μg/kg. Further mining of the same data based on a ‘non-targeted peak finding’ algorithm and the use of full MS and MS/MS accurate mass data allowed the detection and identification of 19 ergot alkaloids that are commonly not included in most analytical methods using QqQ instruments. Some of these alkaloids are reported for the first time in naturally contaminated samples.

Pattern and distribution of ergot alkaloids in cereals and cereal products from European countries

This paper reports on the occurrence of ergot alkaloids in cereals and cereal products in Europe. It includes occurrence data our group previously submitted to the European Food Safety Authority and new data we gathered afterwards. A total of 1,065 samples of cereals and cereal products intended for human consumption and animal feeding were analysed by liquid chromatography-tandem mass spectrometry for the presence of ergot alkaloids. The sample set included rye-, wheat- and multigrain-based food as well as rye-, wheat- and triticale-based feed. The study revealed that 59% of the analysed food and feed samples were contaminated with ergot alkaloids to some extent. In 55% of the samples, the levels of the -ine isomers were above the limit of quantification (LOQ), while contamination with the -inine isomers was found in 51% of the samples. The median values for the main ergot alkaloids (-ine forms) and the epimers (-inine forms) were 1 and 2 μg/kg, respectively. Ergot alkaloids were present in 84% of rye food, 67% of wheat food, 48% of multigrain food, 52% of rye feed, 27% of wheat feed, and 44% of triticale feed at total alkaloid levels ranging from ≤1 (LOQ) to 12,340 μg/kg. Though the highest frequencies of contamination were observed for food samples, the feed samples, in particular Swiss rye feed, accounted for the highest levels of ergot alkaloids. The frequencies and levels of contamination were significantly lower in organic samples compared to conventional samples. Maximum levels of individual ergot alkaloids up to 3,270 μg/kg (for ergotamine) were observed. Overall, ergosine, ergokryptine and ergocristine were the frequently occurring ergot alkaloids. The co-occurrence of all six ergot alkaloids was noted in 35% of the positive samples. Occurrence of a single ergot alkaloid was mainly observed for ergometrine.

Novel solid-phase extraction for epimer-specific quantitation of ergot alkaloids in rye flour and wheat germ oil

Ergot alkaloids and their epimer-specific determination have gained increasing importance for food safety. A solid-phase extraction and cleanup method based on sodium-neutralized strong cation exchange (Na(+)-SCX) was developed to quantitate 12 priority ergot alkaloids in rye flour and wheat germ oil by HPLC fluorescence analysis. Sample preparation is achieved by omitting acidic and alkaline conditions enabling minimized epimerization, which is necessary to determine ergot alkaloids according to their natural distribution in foods. Ergot alkaloids are eluted from SCX-column by forming ion pairs using a sodium hexanesulfonate containing solution which prevents epimerization for at least 96 h. Method validation yielded recoveries of 80-120% (rye flour) and 71-96% (wheat germ oil) with a maximum limit of quantitation (LOQ) of 2.0 μg kg(-1) per ergot alkaloid for both matrices. The applicability of the developed method was demonstrated by analyzing 16 samples from German retail markets: 9 rye flours (max 178 ± 5 μg kg(-1)) and, reported for the first time, 7 wheat germ oils (max 56.8 ± 2.7 μg kg(-1)) expressed as the sum of 12 ergot alkaloids.

Degradation and epimerization of ergot alkaloids after baking and in vitro digestion

The degradation and epimerization of ergot alkaloids (EAs) in rye flour were investigated after baking cookies and subsequently subjecting them to an in vitro digestion model. Different steps of digestion were analyzed using salivary, gastric, and duodenal juices. The degradation and bidirectional conversion of the toxicologically relevant (R)-epimers and the biologically inactive (S)-epimers for seven pairs of EAs were determined by a HPLC method coupled with fluorescence detection. Baking cookies resulted in degradation of EAs (2-30 %) and a shift in the epimeric ratio toward the (S)-epimer for all EAs. The applied digestion model led to a selective toxification of ergotamine and ergosine, two ergotamine-type EAs. The initial percentage of the toxic (R)-epimer in relation to the total toxin content was considerably increased after digestion of cookies. Ergotamine and ergosine increased from 32 to 51 % and 35 to 55 %, respectively. In contrast, EAs of the ergotoxine type (ergocornine, α- and β-ergocryptine, and ergocristine) showed an epimeric shift toward their biologically inactive (S)-epimers. Further experiments indicated that the selective epimerization of ergotamine EAs occurs in the duodenal juice only. These results demonstrate that toxification of EAs in the intestinal tract should be taken into consideration.

Multiclass mycotoxin analysis in food, environmental and biological matrices with chromatography/mass spectrometry

Mold metabolites that can elicit deleterious effects on other organisms are classified as mycotoxins. Human exposure to mycotoxins occurs mostly through the intake of contaminated agricultural products or residues due to carry over or metabolite products in foods of animal origin such as milk and eggs, but can also occur by dermal contact and inhalation. Mycotoxins contained in moldy foods, but also in damp interiors, can cause diseases in humans and animals. Nephropathy, various types of cancer, alimentary toxic aleukia, hepatic diseases, various hemorrhagic syndromes, and immune and neurological disorders are the most common diseases that can be related to mycotoxicosis. The absence or presence of mold infestation and its propagation are seldom correlated with mycotoxin presence. Mycotoxins must be determined directly, and suitable analytical methods are necessary. Hundreds of mycotoxins have been recognized, but only for a few of them, and in a restricted number of utilities, a maximum acceptable level has been regulated by law. However, mycotoxins seldom develop alone; more often various types and/or classes form in the same substrate. The co-occurrence might render the individual mycotoxin tolerance dose irrelevant, and therefore the mere presence of multiple mycotoxins should be considered a risk factor. The advantage of chromatography/mass spectrometry (MS) is that many compounds can be determined and confirmed in one analysis. This review illustrates the state-of-the-art of mycotoxin MS-based analytical methods for multiclass, multianalyte determination in all the matrices in which they appear. A chapter is devoted to the history of the long-standing coexistence and interaction among humans, domestic animals and mycotoxicosis, and the history of the discovery of mycotoxins. Quality assurance, although this topic relates to analytical chemistry in general, has been also examined for mycotoxin analysis as a preliminary to the systematic literature excursus. Sample handling is a crucial step to devise a multiclass analytical method; so when possible, it has been treated separately for a better comparison before tackling the instrumental part of the whole analytical method. This structure has resulted sometimes in unavoidable redundancies, because it was also important to underline the interconnection. Most reviews do not deal with all the possible mycotoxin sources, including the environmental ones. The focus of this review is the analytical methods based on MS for multimycotoxin class determination. Because the final purpose to devise multimycotoxin analysis should be the assessment of the danger to health of exposition to multitoxicants of natural origin (and possibly also the interaction with anthropogenic contaminants), therefore also the analytical methods for environmental relevant mycotoxins have been thoroughly reviewed. Finally, because the best way to shed light on actual risk assessment could be the individuation of exposure biomarkers, the review covers also the scarce literature on biological fluids.

Developments in mycotoxin analysis: an update for 2009-2010

This review highlights developments in mycotoxin analysis and sampling over a period between mid-2009 and mid-2010. It covers the major mycotoxins aflatoxins, Alternaria toxins, ergot alkaloids, fumonisins, ochratoxin, patulin, trichothecenes, and zearalenone. New and improved methods for mycotoxins continue to be published. Immunological-based method developments continue to be of wide interest in a broad range of formats. Multimycotoxin determination by LC-MS/MS is now being targeted at the specific ranges of mycotoxins and matrices of interest or concern to the individual laboratory. Although falling outside the main emphasis of the review, some aspects of natural occurrence have been mentioned, especially if linked to novel method developments.

Ergometrinine

The absolute configuration of ergometrinine, C₁₉H₂₃N₃O₂ {systematic name: (6aR,9S)-N-[(S)-1-hy­droxy­propan-2-yl]-7-methyl-4,6,6a,7,8,9-hexa­hydro­indolo[4,3-fg]quinoline-9-carb­ox­amide}, was established based on epimerization reaction of ergometrine, which was followed by preparative HPLC. The non-aromatic ring (ring C of the ergoline skeleton) directly fused to the aromatic rings is nearly planar [maximum deviation = 0.271 (3) Å] and shows an envelope conformation, whereas ring D, involved in an intra­molecular N—H⋯N hydrogen bond, exibits a slightly distorted chair conformation. The structure displays undulating layers in the ac plane formed by O—H⋯O and N—H⋯O hydrogen bonds.