scholarly journals Assessment of the Optimum Linker Tethering Site of Alternariol Haptens for Antibody Generation and Immunoassay Development

Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 883
Author(s):  
Luis G. Addante-Moya ◽  
Antonio Abad-Somovilla ◽  
Antonio Abad-Fuentes ◽  
Consuelo Agulló ◽  
Josep V. Mercader

Immunochemical methods for mycotoxin analysis require antigens with well-defined structures and antibodies with outstanding binding properties. Immunoreagents for the mycotoxins alternariol and/or alternariol monomethyl ether have typically been obtained with chemically uncharacterized haptens, and antigen conjugates have most likely been prepared with mixtures of functionalized molecules. For the first time, total synthesis was performed, in the present study, to obtain two haptens with opposite linker attachment locations. The functionalized synthetic haptens were purified and deeply characterized by different spectrometric methods, allowing the preparation of bioconjugates with unequivocal structures. Direct and indirect competitive enzyme-linked immunosorbent assays, using homologous and heterologous conjugates, were employed to extensively evaluate the generated immunoreagents. Antibodies with high affinity were raised from conjugates of both haptens, and a structure-activity relationship between the synthetic haptens and the specificity of the generated antibodies could be established. These results pave the way for the development of novel highly sensitive immunoassays selective of one or two of these Alternaria mycotoxins.

2008 ◽  
Vol 1 (2) ◽  
pp. 175-188 ◽  
Author(s):  
V. Ostry

Microfungi of the genus Alternaria are ubiquitous pathogens and saprophytes. Many species of the genus Alternaria commonly cause spoilage of various food crops in the field or post-harvest decay. Due to their growth even at low temperatures, they are also responsible for spoilage of these commodities during refrigerated transport and storage. Several Alternaria species are known producers of toxic secondary metabolites - Alternaria mycotoxins. A. alternata produces a number of mycotoxins, including alternariol, alternariol monomethyl ether, altenuene, altertoxins I, II, III, tenuazonic acid and other less toxic metabolites. Tenuazonic acid is toxic to several animal species, e.g. mice, chicken, dogs. Alternariol, alternariol monomethyl ether, altenuene and altertoxin I are not very acutely toxic. There are several reports on the mutagenicity and genotoxicity of alternariol, and alternariol monomethyl ether. Alternariol has been identified as a topoisomerase I and II poison which might contribute to the impairment of DNA integrity in human colon carcinoma cells. Analytical methods to determine Alternaria toxins are largely based on procedures, involving cleanup by solvent partitioning or solid phase extraction, followed by chromatographic separation techniques, in combination with ultraviolet, fluorescence, electrochemical and mass spectroscopic detection. A large number of Alternaria metabolites has been reported to occur naturally in food commodities (e.g. fruit, vegetables, cereals and oil plants). Alternariol, alternariol monomethyl ether and tenuazonic acid were frequently detected in apples, apple products, mandarins, olives, pepper, red pepper, tomatoes, tomato products, oilseed rape meal, sunflower seeds, sorghum, wheat and edible oils. Alternariol and alternariol monomethyl ether were detected in citrus fruit, Japanese pears, prune nectar, raspberries, red currant, carrots, barley and oats. Alternariol monomethyl ether and tenuazonic acid were detected in melon. Natural occurrence of alternariol has been reported in apple juice, cranberry juice, grape juice, prune nectar, raspberry juice, red wine and lentils.


2021 ◽  
Vol 104 (3) ◽  
pp. 153-162
Author(s):  
Alexandra Stanislavovna Orina* ◽  
Olga Pavlovna Gavrilova ◽  
Tatyana Yuryevna Gagkaeva ◽  
Nadezhda Nikolayevna Gogina

The ubiquitous occurrence of Alternaria fungi belonging to sections Alternaria and Infectoriae was confirmed using real-time PCR in wheat, barley and oat grain grown in West Siberia in 2018‒2019. The DNA amount of Alternaria section Alternaria fungi varied from 53×10-4 to 21731×10-4 pg/ng and on average exceeded the DNA amount of Alternaria section Infectoriae fungi by 4.5‒14.6 times, depending on the crop and harvest year.The average DNA amount of Alternaria fungi belonging to both sections in the oat grain was lower than in wheat and barley grain. The grain samples from Altay region were the most infected with Alternaria fungi. The alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), and tenuazonic acid (TeA) mycotoxins produced by Alternaria fungi were detected by HPLC-MS/MS in 23 %, 6 %, 85 %, and 83 % of analyzed grain samples, respectively. The majority (61 %) of the samples contained two Alternaria mycotoxins in the grain (mainly TEN and TeA), 19 % of the samples three mycotoxins, and only one sample all four together. In the most of samples the content of Alternaria mycotoxins did not exceed 100 μg/kg, and only TeA content was higher (from 113 to 14963 μg/kg) than others. The significant differences in grain crops by the Alternaria mycotoxins content were revealed: more amounts of AOH, AME, and less amount of TEN were found in oat grain then in barley grain. A high positive significant correlation between the DNA amount of Alternaria section Alternaria fungi and TeA was established that indicates the role of these fungi as the main producers of TeA in the grain.


2008 ◽  
Vol 71 (6) ◽  
pp. 1262-1265 ◽  
Author(s):  
M. P. AZCARATE ◽  
A. PATRIARCA ◽  
L. TERMINIELLO ◽  
V. FERNÁNDEZ PINTO

The natural occurrence of Alternaria mycotoxins in Argentinean wheat from the zone 5 South during the 2004 to 2005 harvest was investigated in 64 wheat samples. All samples were highly contaminated with a wide range of fungal species. Alternaria was found as the main component of the mycota, with an infection percentage of 100%. Three mycotoxins produced by species of Alternaria were determined in wheat: alternariol, alternariol monomethyl ether, and tenuazonic acid. Alternariol was detected in 4 (6%) of 64 samples, with a range of 645 to 1,388 μg/kg (mean of 1,054 μg/kg); alternariol monomethyl ether, with a range of 566 to 7,451 μg/kg (mean of 2,118 μg/kg) in 15 (23%) of 64 samples; and tenuazonic acid in 12 (19%) of 64 samples, with a range of 1,001 to 8,814 μg/kg (mean, 2,313 μg/kg). Alternariol monomethyl ether was the predominant toxin, but tenuazonic acid was detected in higher concentrations. Alternariol was present in fewer samples and in lower levels than were the other toxins. Tenuazonic acid and alternariol monomethyl ether occurred together in four samples, while tenuazonic acid and alternariol co-occurred in one sample. This the first report of the natural occurrence of Alternaria mycotoxins in Argentinean wheat. Toxin levels were high, probably due to the heavy infection with Alternaria species found in the samples.


Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 275 ◽  
Author(s):  
Mario Masiello ◽  
Stefania Somma ◽  
Antonia Susca ◽  
Veronica Ghionna ◽  
Antonio Francesco Logrieco ◽  
...  

Black point is a fungal disease of wheat, mainly associated with mycotoxigenic Alternaria species. Affected wheat kernels are characterized by dark brown discolouration of the embryo region and reduction of grain quality. Potential risk is the possible accumulation of Alternaria mycotoxins, alternariol (AOH), alternariol-monomethyl ether (AME), tenuazonic acid (TA), and altenuene (ALT), provided by haemato-toxic, genotoxic, and mutagenic activities. One hundred and twenty durum wheat samples belonging to 30 different genotypes grown in Bologna and Modena areas, in Italy, showing black point symptoms, were analyzed for Alternaria species and their mycotoxin contamination. Alternariol was selected as an indicator of the capability of the Alternaria species to produce mycotoxin in vivo in field conditions. The data showed that Alternaria species occurred in 118 out of 120 wheat kernels samples, with the incidence of infected kernels ranging between 1% and 26%. Moreover, AOH was detected by using a HPLC with a diode array detector (LC-DAD) in 98 out of 120 samples with values ranging between 24 and 262 µg Kg−1. Ninety-two Alternaria representative strains, previously identified morphologically, were identified at species/section level using gene sequencing, and therefore were analyzed for their mycotoxin profiles. Eighty-four strains, phylogenetically grouped in the Alternaria section, produced AOH, AME, and TA with values up to 8064, 14,341, and 3683 µg g−1, respectively, analyzed by using a LC-DAD. On the other hand, eight Alternaria strains, included in Infectoriae Section, showed a very low or no capability to produce mycotoxins.


2018 ◽  
Vol 11 (1) ◽  
pp. 159-174 ◽  
Author(s):  
L. Gambacorta ◽  
D. Magistà ◽  
G. Perrone ◽  
S. Murgolo ◽  
A.F. Logrieco ◽  
...  

Forty-five samples of a landrace of sweet pepper (Capsicum annuum) widely cultivated in Basilicata (Italy) were screened for 17 mycotoxins and potential toxigenic fungal species. Two different LC-MS/MS methods were used for the determination of aflatoxins, ochratoxin A (OTA), Fusarium mycotoxins zearalenone (ZEA), fumonisins (FB1 and FB2), nivalenol (NIV), deoxynivalenol (DON), T-2 and HT-2 toxins and Alternaria mycotoxins altenuene (ALT), alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TTX) and tenuazonic acid (TeA). Frequency of potential toxigenic fungal species occurrence was: 87% Aspergillus Sect. Nigri; 58% Aspergillus Sect. Flavi; 38% Aspergillus Sect. Circumdati; 42% Alternaria spp.; 33% Penicillium spp. and 20% Fusarium spp. Frequency of mycotoxin occurrence and mean of positives were: 51% OTA, 29.5 µg/kg, 5 samples above the EU limit of 20 µg/kg; 31% aflatoxins, 12.8 µg/kg, two samples above the EU limit of 5 µg/kg for aflatoxin B1; 91% ZEA, 1.4 µg/kg; 78% FB2, 7.6 µg/kg; 58% FB1, 22.8 µg/kg; 38% NIV, 39.5 µg/kg; 36% DON, 6.9 µg/kg; 20% T-2 toxin, 5.6 µg/kg and 22% HT-2 toxin, 13.8 µg/kg. For the Alternaria mycotoxins, 100% of samples contained TeA, 4817.9 µg/kg; 93% TTX, 29.7 µg/kg; 56% AOH, 114.4 µg/kg; 33% AME, 13.0 µg/kg and 9% ALT, 61.7 µg/kg. Co-occurrence of mycotoxins in each sample ranged from 2 to 16 mycotoxins (mean 7). No statistical correlation was found between moulds and their mycotoxins occurrence. Within the four groups of peppers collected herein (fresh, dried, grounded and fried) higher percentages of contamination and mycotoxin levels were measured in grounded peppers, whereas much lower values were observed for fried peppers. The high percentages of positive samples and the high levels of some mycotoxins observed in this study confirm the susceptibility of peppers to mycotoxin contamination and claims for an improvement of the conditions used during production and drying process.


1995 ◽  
Vol 58 (10) ◽  
pp. 1133-1134 ◽  
Author(s):  
SOFÍA N. CHULZE ◽  
ADRIANA M. TORRES ◽  
ANA M. DALCERO ◽  
MIRIAM G. ETCHEVERRY ◽  
MARÍA L. RAMÍREZ ◽  
...  

A survey of 150 sunflower-seed samples was carried out to evaluate the contamination from infection with Alternaria alternata with alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA). A high percentage of the samples was contaminated with AOH (85%), AME, (47%), and TA (65%). The average levels detected were 187 μg/kg for AOH, 194 μg/kg for AME, and 6,692, μg/kg for TA. When sunflower seeds fermented by Alternaria alternata were processed under laboratory conditions to obtain the oil and meal, different distributions of Alternaria toxins between the oil and the meal were observed: whereas AOH, AME, and TA were detected in the meal, only AME and TA were detected in the oil, and the latter in a low percentage.


Author(s):  
Francesco Crudo ◽  
Georg Aichinger ◽  
Jovana Mihajlovic ◽  
Elisabeth Varga ◽  
Luca Dellafiora ◽  
...  

AbstractThe human gut microbiota plays an important role in the maintenance of human health. Factors able to modify its composition might predispose the host to the development of pathologies. Among the various xenobiotics introduced through the diet, Alternaria mycotoxins are speculated to represent a threat for human health. However, limited data are currently available about the bidirectional relation between gut microbiota and Alternaria mycotoxins. In the present work, we investigated the in vitro effects of different concentrations of a complex extract of Alternaria mycotoxins (CE; containing eleven mycotoxins; e.g. 0.153 µM alternariol and 2.3 µM altersetin, at the maximum CE concentration tested) on human gut bacterial strains, as well as the ability of the latter to metabolize or adsorb these compounds. Results from the minimum inhibitory concentration assay showed the scarce ability of CE to inhibit the growth of the tested strains. However, the growth kinetics of most of the strains were negatively affected by exposure to the various CE concentrations, mainly at the highest dose (50 µg/mL). The CE was also found to antagonize the formation of biofilms, already at concentrations of 0.5 µg/mL. LC–MS/MS data analysis of the mycotoxin concentrations found in bacterial pellets and supernatants after 24 h incubation showed the ability of bacterial strains to adsorb some Alternaria mycotoxins, especially the key toxins alternariol, alternariol monomethyl ether, and altersetin. The tendency of these mycotoxins to accumulate within bacterial pellets, especially in those of Gram-negative strains, was found to be directly related to their lipophilicity.


2018 ◽  
Vol 11 (4) ◽  
pp. 625-633 ◽  
Author(s):  
N. Estiarte ◽  
A. Crespo-Sempere ◽  
S. Marín ◽  
V. Sanchis ◽  
A.J. Ramos

The occurrence of two Alternaria mycotoxins, alternariol (AOH) and alternariol monomethyl ether (AME) and the presence of conidia from Alternaria spp., were investigated throughout the food production chain of two businesses, one which uses organic fruit and the other non-organic. For this purpose, a propidium monoazide (PMA) treatment followed by a quantitative Real Time PCR (qPCR) was used to detect and quantify viable conidia exclusively. Results demonstrated that 68.4% of the total raw fruit analysed was contaminated with viable Alternaria spp. Regarding the mycotoxin occurrence, only a few samples were contaminated with AME, while 35% of raw tomatoes tested positive for AOH in the organic producer and 21% in the non-organic producer. AOH was present in samples analysed before heat treatment, while almost no mycotoxins were found in the final products of the organic producer. However, in the non-organic producer, 47% of the tomato concentrates were contaminated.


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