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Articoli di riviste sul tema "Cyclopiazonic acid"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 20 febbraio 2023

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1

Peterson, Robert E., Gail M. Shannon e Odette L. Shotwell. "Purification of Cyclopiazonic Acid by Liquid Chromatography". Journal of AOAC INTERNATIONAL 72, n. 2 (1 marzo 1989): 332–35. http://dx.doi.org/10.1093/jaoac/72.2.332.

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Abstract A purification procedure for cyclopiazonic acid has been developed, using sequential preparative and semi-preparative liquid chromatography. Crude cyclopiazonic acid (324 mg) was extracted from a 1 L fermentation medium with chloroform-methanol (80 + 20), dried, dissolved in chloroform, and chromatographed on an oxalic acid/ silica preparative column with chloroform-methanol (99 + 1) as the eluant. A semi-preparative oxalic acid/silica column and chloroform- methanol (99.5 + 0.5) were then used for rechromatography of the partially purified cyclopiazonic acid. This second chromatographic treatment yielded fractions from which cyclopiazonic acid was readily crystallized (106.7 mg; 33% recovery). Analytical chromatography was developed using an amino column in an ion-exchange mode, with a methanol-phosphate buffer eluant. Response was linear from 10 to 800 μg/injection of standard solutions. Cyclopiazonic acid chemically binds sodium from soda-lime vials.

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2

Chang-Yen, Ivan, e Keshore Bidasee. "Improved Spectrophotometric Determination of Cyclopiazonic Acid in Poultry Feed and Corn". Journal of AOAC INTERNATIONAL 73, n. 2 (1 marzo 1990): 257–59. http://dx.doi.org/10.1093/jaoac/73.2.257.

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Abstract An improved visible spectrophotometric method has been developed for cyclopiazonic acid in poultry feed and corn. The method Is based on the reaction of cyclopiazonic acid with Ehrlich reagent and detection at 580 nm. Reaction conditions were optimized with respect to reaction and measurement times and acid and Ehrlich reagent concentrations. Calibration curves were linear from 1 to 20 μg cyclopiazonic acid in 3 mL Ehrlich reagent, with a lower detection limit of 0.08 mg/kg for 50 g samples of poultry feed and corn. Recoveries from 50 g samples of poultry feed spiked with cyclopiazonic ranging from 0.16 to 1.20 mg/kg averaged 93.8%. Moldy corn and poultry feed samples analyzed by this method contained between 1 and 4 mg/kg cyclopiazonic acid.

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3

Matsudo, Takanao, e Masaoki Sasaki. "Simple Determination of Cyclopiazonic Acid". Bioscience, Biotechnology, and Biochemistry 59, n. 3 (gennaio 1995): 355–57. http://dx.doi.org/10.1271/bbb.59.355.

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4

Chang, P. K., e K. C. Ehrlich. "Cyclopiazonic acid biosynthesis byAspergillus flavus". Toxin Reviews 30, n. 2-3 (10 maggio 2011): 79–89. http://dx.doi.org/10.3109/15569543.2011.576795.

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5

van Rooyen, P. H. "Structure of α-cyclopiazonic acid". Acta Crystallographica Section C Crystal Structure Communications 48, n. 3 (15 marzo 1992): 551–52. http://dx.doi.org/10.1107/s0108270191010053.

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6

Natsume, Mitsutaka, e Hideaki Muratake. "Total Synthesis of (±)-a-Cyclopiazonic Acid". HETEROCYCLES 23, n. 5 (1985): 1111. http://dx.doi.org/10.3987/r-1985-05-1111.

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7

Diaz, G., W. Thompson e P. Martos. "Stability of cyclopiazonic acid in solution". World Mycotoxin Journal 3, n. 1 (1 febbraio 2010): 25–33. http://dx.doi.org/10.3920/wmj2009.1170.

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Cyclopiazonic acid (CPA) is an important mycotoxin given its toxicity and prevalence in foods and feeds. There is tremendous interest in developing analytical methods that include CPA as part of a multi-residue mycotoxin routine, but there appears to be considerable difficulty in analysing it using liquid chromatography with electrospray ionisation tandem mass spectrometry (LC-MS/MS). During the development of a multi-residue method for mycotoxins including CPA, a number of issues were discovered under routine and common analytical conditions that have an impact on the determination of CPA, including: (1) at the ng/ml level CPA reacts with ambient oxygen from the headspace of the vial, an effect that decreases its concentration linearly; (2) CPA readily adsorbs to plastic in a reversible fashion; (3) CPA is acid hydrolysed with formic acid; (4) CPA reacts with the column stationary phase affecting chromatographic parameters; and (5) CPA presents significant carry-over issues. In an effort to find solutions to these problems we found that CPA can be protected from reacting with oxygen by adding 1 µg/ml ascorbic acid and that its carry-over can be reduced to a negligible level by injecting ammonia between injections of solutions containing CPA, even with formic acid in the mobile phase. Chromatographic conditions for CPA have been optimised in consideration of all of the aforementioned concerns.

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8

Nishie, K., R. J. Cole e J. W. Dorner. "Toxicity and neuropharmacology of cyclopiazonic acid". Food and Chemical Toxicology 23, n. 9 (settembre 1985): 831–39. http://dx.doi.org/10.1016/0278-6915(85)90284-4.

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9

Ahmad, Mushtaq, Shahid Hameed, Oleksandr Zhurakovskyi e Humaira Inayat. "α‐Cyclopiazonic Acid from Synthesis Perspective". ChemistrySelect 5, n. 45 (2 dicembre 2020): 14408–15. http://dx.doi.org/10.1002/slct.202003097.

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10

MUNIMBAZI, CÉLESTIN, JYOTI SAXENA, WEI-YUN J. TSAI e LLOYD B. BULLERMAN. "Inhibition of Production of Cyclopiazonic Acid and Ochratoxin A by the Fungicide Iprodione‡". Journal of Food Protection 60, n. 7 (1 luglio 1997): 849–52. http://dx.doi.org/10.4315/0362-028x-60.7.849.

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Aspergillus flavus NRRL 1290 and Aspergillus ochraceus NRRL 3174 were grown on a glucose-salts medium and yeast extract-sucrose broth containing the fungicide iprodione at concentrations of 0, 1,3,5, 10, 15, and 20 μg of active ingredient per ml of growth medium. Cultures were analyzed for cyclopiazonic acid, ochratoxin A, and mycelium production after 4,7, 10, 14, and 21 days of incubation at 25°C. Increasing concentrations of iprodione in the growth media resulted in greater reduction of cyclopiazonic acid, ochratoxin A, and mycelium production at the end of each incubation period. More than 50% reduction of cyclopiazonic acid, ochratoxin A, and mycelium production was observed when iprodione was added to growth media at a concentration of 5 μg/ml of medium. Higher concentrations of iprodione (10 to 20 μg/ml of growth medium) inhibited the production of cyclopiazonic acid and mycelium by A. flavus NRRL 1290 almost completely, but not the production of ochratoxin A and mycelium by A. ochraceus NRRL 3174.

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11

Huchet-Cadiou, C., V. Bonnet, W. Meme e C. Leoty. "Hypogravity increases cyclopiazonic acid sensitivity of rat soleus muscle". Journal of Applied Physiology 80, n. 4 (1 aprile 1996): 1100–1104. http://dx.doi.org/10.1152/jappl.1996.80.4.1100.

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The functional capacity of skeletal muscle sarcoplasmic reticulum was explored in slow rat soleus muscle after 21 days of hindlimb suspension. The sarcoplasmic reticulum function was assessed in intact and saponin-skinned fibers by using cyclopiazonic acid, a specific Ca(2+)-adenosinetriphosphatase inhibitor. After hindlimb unweighting, the sensitivity to cyclopiazonic acid of intact and skinned soleus fibers becomes similar to that found in fast-twitch muscles. This change could be related to the expression of fast Ca2(+)-adenosinetriphosphatase-pump protein in unloaded soleus muscles and agrees with a transformation of soleus muscle from slow- to fast-twitch type. These results also indicate that specific pharmacological tools, like cyclopiazonic acid, could be used to analyze subcellular functional changes due to hindlimb unweighting.

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12

Bost, K. L., e M. J. Mason. "Thapsigargin and cyclopiazonic acid initiate rapid and dramatic increases of IL-6 mRNA expression and IL-6 secretion in murine peritoneal macrophages." Journal of Immunology 155, n. 1 (1 luglio 1995): 285–96. http://dx.doi.org/10.4049/jimmunol.155.1.285.

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Abstract Two different inhibitors of endosomal calcium ATPase activity, cyclopiazonic acid and thapsigargin, were shown to release a common intracellular calcium pool in normal, murine macrophages. Furthermore, the release of this pool was accompanied by increased calcium uptake from the extracellular medium. The activity of these inhibitors was linked to an important biologic response, because both cyclopiazonic acid and thapsigargin induced rapid and dramatic increases in IL-6 mRNA expression and secretion. Compared with control cultures, macrophages treated with these inhibitors increased IL-6 mRNA expression approximately 10-fold by 15 min and approximately 20-fold by 2 h, as determined using quantitative competitive-reverse transcribed-PCRs. The increased mRNA expression was coupled to translation and secretion of this monokine since cyclopiazonic acid and thapsigargin induced significant increases in IL-6 secretion as early as 2 h, and up to approximately 70-fold increases by 20 h, when compared with control cultures. Taken together, these results demonstrate that both cyclopiazonic acid and thapsigargin generate potent intracellular signals that initiate rapid and dramatic production of IL-6. Both thapsigargin and cyclopiazonic acid increased IL-6 mRNA expression at 15 min in the absence of Ca2+ influx from the extracellular medium. These results suggest that events associated with endosomal Ca(2+)-ATPase inhibition contribute to the activation of normal macrophages as defined by increased monokine secretion.

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13

Horn, B. W., e J. W. Dorner. "Regional Differences in Production of Aflatoxin B1 and Cyclopiazonic Acid by Soil Isolates ofAspergillus flavus along a Transect within the United States". Applied and Environmental Microbiology 65, n. 4 (1 aprile 1999): 1444–49. http://dx.doi.org/10.1128/aem.65.4.1444-1449.1999.

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ABSTRACT Soil isolates of Aspergillus flavus from a transect extending from eastern New Mexico through Georgia to eastern Virginia were examined for production of aflatoxin B1 and cyclopiazonic acid in a liquid medium. Peanut fields from major peanut-growing regions (western Texas; central Texas; Georgia and Alabama; and Virginia and North Carolina) were sampled, and fields with other crops were sampled in regions where peanuts are not commonly grown. The A. flavus isolates were identified as members of either the L strain (n = 774), which produces sclerotia that are >400 μm in diameter, or the S strain (n = 309), which produces numerous small sclerotia that are <400 μm in diameter. The S-strain isolates generally produced high levels of aflatoxin B1, whereas the L-strain isolates were more variable in aflatoxin production; variation in cyclopiazonic acid production also was greater in the L strain than in the S strain. There was a positive correlation between aflatoxin B1 production and cyclopiazonic acid production in both strains, although 12% of the L-strain isolates produced only cyclopiazonic acid. Significant differences in production of aflatoxin B1 and cyclopiazonic acid by the L-strain isolates were detected among regions. In the western half of Texas and the peanut-growing region of Georgia and Alabama, 62 to 94% of the isolates produced >10 μg of aflatoxin B1 per ml. The percentages of isolates producing >10 μg of aflatoxin B1per ml ranged from 0 to 52% in the remaining regions of the transect; other isolates were often nonaflatoxigenic. A total of 53 of the 126 L-strain isolates that did not produce aflatoxin B1 or cyclopiazonic acid were placed in 17 vegetative compatibility groups. Several of these groups contained isolates from widely separated regions of the transect.

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14

Tosun, M., Y. Erac, C. Selli e N. Karakaya. "Sarcoplasmic-endoplasmic reticulum Ca2+-ATPase inhibition prevents endothelin A receptor antagonism in rat aorta". American Journal of Physiology-Heart and Circulatory Physiology 292, n. 4 (aprile 2007): H1961—H1966. http://dx.doi.org/10.1152/ajpheart.00298.2006.

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This study tested whether sarcoplasmic-endoplasmic reticulum Ca2+-ATPase regulates the ability of endothelin receptor antagonist to inhibit the endothelin-1 constriction. The endothelin A receptor antagonist BQ-123 (1 μM) completely relaxed constriction to 10 nM endothelin-1 in endothelium-denuded rat aorta. Challenge with cyclopiazonic acid (10 μM), a sarcoplasmic-endoplasmic reticulum Ca2+-ATPase inhibitor, during the plateau of endothelin-1 constriction enhanced the constriction by ∼30%. BQ-123 relaxed the endothelin-1 plus cyclopiazonic acid constriction by only ∼10%. In contrast, prazosin (1 μM), an α-adrenergic receptor antagonist, still completely relaxed the 0.3 μM phenylephrine constriction in the presence of cyclopiazonic acid. Verapamil relaxed the endothelin-1 plus cyclopiazonic acid constriction by ∼30%, whereas Ni2+ and 2-aminoethoxydiphenyl borate, nonselective cation channel and store-operated channel blockers, respectively, completely relaxed the constriction. These results suggest that lowered sarcoplasmic-endoplasmic reticulum Ca2+-ATPase activity selectively decreases the ability of endothelin receptor antagonist to inhibit the endothelin A receptor. The decreased antagonism may be related to the opening of store-operated channels and subsequent greater internalization of endothelin A receptor.

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15

Maragos, C. "Photolysis of cyclopiazonic acid to fluorescent products". World Mycotoxin Journal 2, n. 1 (1 febbraio 2009): 77–84. http://dx.doi.org/10.3920/wmj2008.1088.

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Cyclopiazonic acid (CPA) is a mycotoxin produced by some of the same species of fungi that produce the more widely known aflatoxins. As a consequence it has been found previously that CPA and the aflatoxins may co-occur in commodities under certain conditions. CPA, which is a substituted indole, has a chromophore with absorptions in the ultraviolet (UV) region (223 nm, 278 nm). Quantification of CPA is commonly accomplished by liquid chromatographic separation followed by detection of one of the UV absorbances. CPA has not previously been described as fluorescent, and it likely is not. However, herein we report that, following exposure to high intensity UV light in a photochemical reactor, fluorescent products of CPA are produced. In methanol or aqueous acetonitrile these products have an excitation maximum of 372 nm and an emission maximum of 462 nm. Upon exposure to UV light for extended periods a decrease in the absorbance of CPA at 223 nm and 278 nm and a concomitant increase in fluorescence was observed. CPA and aflatoxin B1 were separated by reverse-phase liquid chromatography and the eluant was subjected to post-column photolysis, which allowed the fluorescence detection of both toxins. The ability to photolyse CPA and detect this toxin by fluorescence may open up new avenues for determination of this mycotoxin alone or together with the aflatoxins.

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16

Ostry, V., J. Toman, Y. Grosse e F. Malir. "Cyclopiazonic acid: 50th anniversary of its discovery". World Mycotoxin Journal 11, n. 1 (23 febbraio 2018): 135–48. http://dx.doi.org/10.3920/wmj2017.2243.

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In 1968, the mycotoxin cyclopiazonic acid (CPA) was first discovered and characterised as a chemical substance. Within the following five decades, much has been learned from the results of CPA research. CPA is produced by several Penicillium species (P. griseofulvum, P. camemberti, P. commune, P. dipodomyicola) and Aspergillus species (A. flavus, A. oryzae and A. tamarii). It is widespread on naturally contaminated agricultural raw materials. CPA has been reported to occur in food commodities (e.g. oilseeds, nuts, cereals, dried figs, milk, cheese and meat products) and to possess toxicological significance. CPA is also frequently detected in peanuts and maize; the presence of CPA and aflatoxins in maize and peanuts contaminated with A. flavus suggests that synergism may occur. CPA is toxic to several animal species, such as rats, pigs, guinea pigs, poultry and dogs. After ingesting CPA-contaminated feeds, test animals display severe gastrointestinal upsets and neurological disorders. Organs affected include the liver, kidney, heart, and digestive tract, which show degenerative changes and necrosis. Biologically, CPA is a specific inhibitor of sarco(endo)plasmic reticulum Ca2+-ATPase. Data from toxicological evaluation of aflatoxins and CPA in broiler chickens demonstrate that both aflatoxins and CPA alone and the aflatoxin-CPA combination can adversely affect broiler health. The effects of aflatoxins and CPA combination were additive in most cases.

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17

Porter, J. K., W. P. Norred, R. J. Cole e J. W. Dorner. "Neurochemical Effects of Cyclopiazonic Acid in Chickens". Experimental Biology and Medicine 187, n. 3 (1 marzo 1988): 335–40. http://dx.doi.org/10.3181/00379727-187-42673.

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18

Dorner, Joe W., Richard J. Cole, Deborah J. Erlington, Sucheep Suksupath, Graham H. McDowell e Wayne L. Bryden. "Cyclopiazonic Acid Residues in Milk and Eggs". Journal of Agricultural and Food Chemistry 42, n. 7 (luglio 1994): 1516–18. http://dx.doi.org/10.1021/jf00043a023.

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19

Khera, K. S., R. J. Cole, C. Whalen e J. W. Dorner. "Embryotoxicity study on cyclopiazonic acid in mice". Bulletin of Environmental Contamination and Toxicology 34, n. 1 (dicembre 1985): 423–26. http://dx.doi.org/10.1007/bf01609755.

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SÁNCHEZ, BEATRIZ, MAR RODRÍGUEZ, EVA M. CASADO, ALBERTO MARTÍN e JUAN J. CÓRDOBA. "Development of an Efficient Fungal DNA Extraction Method To Be Used in Random Amplified Polymorphic DNA–PCR Analysis To Differentiate Cyclopiazonic Acid Mold Producers". Journal of Food Protection 71, n. 12 (1 dicembre 2008): 2497–503. http://dx.doi.org/10.4315/0362-028x-71.12.2497.

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A variety of previously established mechanical and chemical treatments to achieve fungal cell lysis combined with a semiautomatic system operated by a vacuum pump were tested to obtain DNA extract to be directly used in randomly amplified polymorphic DNA (RAPD)–PCR to differentiate cyclopiazonic acid–producing and –nonproducing mold strains. A DNA extraction method that includes digestion with proteinase K and lyticase prior to using a mortar and pestle grinding and a semiautomatic vacuum system yielded DNA of high quality in all the fungal strains and species tested, at concentrations ranging from 17 to 89 ng/μl in 150 μl of the final DNA extract. Two microliters of DNA extracted with this method was directly used for RAPD-PCR using primer (GACA)4. Reproducible RAPD fingerprints showing high differences between producer and nonproducer strains were observed. These differences in the RAPD patterns did not differentiate all the strains tested in clusters by cyclopiazonic acid production but may be very useful to distinguish cyclopiazonic acid producer strains from nonproducer strains by a simple RAPD analysis. Thus, the DNA extracts obtained could be used directly without previous purification and quantification for RAPD analysis to differentiate cyclopiazonic acid producer from nonproducer mold strains. This combined analysis could be adaptable to other toxigenic fungal species to enable differentiation of toxigenic and nontoxigenic molds, a procedure of great interest in food safety.

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HAYASHI, Yoshiki, Anthony C. SALES e Takumi YOSHIZAWA. "Cyclopiazonic acid contamination in Japanese commercial rice koji". Mycotoxins 55, n. 1 (2005): 9–15. http://dx.doi.org/10.2520/myco.55.9.

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Rahimian, Roshanak, Cornelis Van Breemen, Delara Karkan, Gregory Dube e Ismail Laher. "Estrogen augments cyclopiazonic acid-mediated, endothelium-dependent vasodilation". European Journal of Pharmacology 327, n. 2-3 (maggio 1997): 143–49. http://dx.doi.org/10.1016/s0014-2999(97)89653-7.

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23

Kuilman-Wahls, Mariëlla E. M., Mònica Sabater Vilar, Lilian de Nijs-Tjon, Roel F. M. Maas e Johanna Fink-Gremmels. "Cyclopiazonic acid inhibits mutagenic action of aflatoxin B1". Environmental Toxicology and Pharmacology 11, n. 3-4 (luglio 2002): 207–12. http://dx.doi.org/10.1016/s1382-6689(01)00119-3.

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Shi, Shibin, Kuo Yuan e Yanxing Jia. "Seven-step total synthesis of α-cyclopiazonic acid". Chinese Chemical Letters 31, n. 2 (febbraio 2020): 401–3. http://dx.doi.org/10.1016/j.cclet.2019.06.048.

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MPHANDE, FINGANI A., BUPE A. SIAME e JOANNE E. TAYLOR. "Fungi, Aflatoxins, and Cyclopiazonic Acid Associated with Peanut Retailing in Botswana". Journal of Food Protection 67, n. 1 (1 gennaio 2004): 96–102. http://dx.doi.org/10.4315/0362-028x-67.1.96.

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Peanuts are important food commodities, but they are susceptible to fungal infestation and mycotoxin contamination. Raw peanuts were purchased from retail outlets in Botswana and examined for fungi and mycotoxin (aflatoxins and cyclopiazonic acid) contamination. Zygomycetes were the most common fungi isolated; they accounted for 41% of all the isolates and were found on 98% of the peanut samples. Among the Zygomycetes, Absidia corymbifera and Rhizopus stolonifer were the most common. Aspergillus spp. accounted for 35% of all the isolates, with Aspergillus niger being the most prevalent (20.4%). Aspergillus flavus/parasiticus were also present and accounted for 8.5% of all the isolates, with A. flavus accounting for the majority of the A. flavus/parasiticus identified. Of the 32 isolates of A. flavus screened for mycotoxin production, 11 did not produce detectable aflatoxins, 8 produced only aflatoxins B1 and B2, and 13 produced all four aflatoxins (B1, B2, G1, and G2) in varying amounts. Only 6 of the A. flavus isolates produced cyclopiazonic acid at concentrations ranging from 1 to 55 μg/kg. The one A. parasiticus isolate screened also produced all the four aflatoxins (1,200 μg/kg) but did not produce cyclopiazonic acid. When the raw peanut samples (n = 120) were analyzed for total aflatoxins, 78% contained aflatoxins at concentrations ranging from 12 to 329 μg/kg. Many of the samples (49%) contained total aflatoxins at concentrations above the 20 μg/kg limit set by the World Health Organization. Only 21% (n = 83) of the samples contained cyclopiazonic acid with concentrations ranging from 1 to 10 μg/kg. The results show that mycotoxins and toxigenic fungi are common contaminants of peanuts sold at retail in Botswana.

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Morio, Yoshiteru, e Ivan F. McMurtry. "Ca2+ release from ryanodine-sensitive store contributes to mechanism of hypoxic vasoconstriction in rat lungs". Journal of Applied Physiology 92, n. 2 (1 febbraio 2002): 527–34. http://dx.doi.org/10.1152/jappl.2002.92.2.527.

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Studies of thapsigargin, cyclopiazonic acid, and ryanodine in isolated pulmonary arteries and smooth muscle cells suggest that release of Ca2+ from inositol 1,4,5-trisphosphate (IP3)- and/or ryanodine-sensitive sarcoplasmic reticulum Ca2+ stores is a component of the mechanism of acute hypoxic pulmonary vasoconstriction (HPV). However, the actions of these agents on HPV in perfused lungs have not been reported. Thus we tested effects of thapsigargin and cyclopiazonic acid, inhibitors of sarcoplasmic reticulum Ca2+-ATPase, and of ryanodine, an agent that either locks the ryanodine receptor open or blocks it, on HPV in salt solution-perfused rat lungs. After inhibition of cyclooxygenase and nitric oxide synthase, thapsigargin (10 nM) and cyclopiazonic acid (5 μM) augmented the vasoconstriction to 0% but not to 3% inspired O2. Relatively high concentrations of ryanodine (100 and 300 μM) blunted HPV in nitric oxide synthase-inhibited lungs. The results indicate that release of Ca2+ from the ryanodine-sensitive, but not the IP3-sensitive, store, contributes to the mechanism of HPV in perfused rat lungs and that Ca2+-ATPase-dependent Ca2+ buffering moderates the response to severe hypoxia.

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Lansden, John A. "Determination of Cyclopiazonic Acid in Peanuts and Corn by Thin Layer Chromatography". Journal of AOAC INTERNATIONAL 69, n. 6 (1 novembre 1986): 964–66. http://dx.doi.org/10.1093/jaoac/69.6.964.

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Abstract A thin layer chromatographic system including densitometry has been developed for determining cyclopiazonic acid in peanuts and corn. Samples are extracted with methanol-chloroform (20 + 80); the extract is stripped of most interferences by partitioning with aqueous sodium bicarbonate followed by acidification and repartitioning with chloroform. After thin layer chromatography and derivatization with dimethylaminobenzaldehyde- HCl spray, the toxin is quantitated by reflection densitometry at 540 nm. The recovery of cyclopiazonic acid averages 90% for peanuts and 85% for corn. The absolute detection limit is 25 ng per spot which translates to a detection limit of 125 μg/kg for a 50 g sample.

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Soares, C., P. Rodrigues, O. Freitas-Silva, L. Abrunhosa e A. Venâncio. "HPLC method for simultaneous detection of aflatoxins and cyclopiazonic acid". World Mycotoxin Journal 3, n. 3 (1 agosto 2010): 225–31. http://dx.doi.org/10.3920/wmj2010.1216.

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Aspergillus species in section Flavi are among the most relevant mycotoxigenic fungi. The organisms are well-known producers of the highly carcinogenic aflatoxins and of other mycotoxins, such as cyclopiazonic acid. Aflatoxins and cyclopiazonic acid analyses can be routinely used for identification purposes within the section. Two separate chromatographic runs with distinct columns and detectors for each toxin were required in previous reports. A straightforward high performance liquid chromatography (HPLC) procedure for the simultaneous detection of these compounds in fungal cultures was developed in the present work using a methanol/water mobile phase, postcolumn photochemical derivatisation and fluorescence detection. The proposed method was tested with standards and fungal extracts of 24 Aspergillus section Flavi strains and compared to the common individual detection of these mycotoxins by HPLC analyses.

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Hahnau, Sabine, e Elmar W. Weiler. "Determination of the mycotoxin cyclopiazonic acid by enzyme immunoassay". Journal of Agricultural and Food Chemistry 39, n. 10 (ottobre 1991): 1887–91. http://dx.doi.org/10.1021/jf00010a041.

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Prasongsidh, B. C., K. Kailasapathy, G. R. Skurray e W. L. Bryden. "Analysis of cyclopiazonic acid in milk by capillary electrophoresis". Food Chemistry 61, n. 4 (aprile 1998): 515–19. http://dx.doi.org/10.1016/s0308-8146(97)00102-7.

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Hymery, Nolwenn, Floriane Masson, Georges Barbier e Emmanuel Coton. "Cytotoxicity and immunotoxicity of cyclopiazonic acid on human cells". Toxicology in Vitro 28, n. 5 (agosto 2014): 940–47. http://dx.doi.org/10.1016/j.tiv.2014.04.003.

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32

Zorzete, Patrícia, Arianne C. Baquião, Danielle D. Atayde, Tatiana A. Reis, Edlayne Gonçalez e Benedito Corrêa. "Mycobiota, aflatoxins and cyclopiazonic acid in stored peanut cultivars". Food Research International 52, n. 1 (giugno 2013): 380–86. http://dx.doi.org/10.1016/j.foodres.2013.03.029.

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33

Maragos, C. M., K. K. Sieve e J. Bobell. "Detection of cyclopiazonic acid (CPA) in maize by immunoassay". Mycotoxin Research 33, n. 2 (5 aprile 2017): 157–65. http://dx.doi.org/10.1007/s12550-017-0275-0.

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34

Chang, Perng-Kuang, Kenneth Ehrlich e Isao Fujii. "Cyclopiazonic Acid Biosynthesis of Aspergillus flavus and Aspergillus oryzae". Toxins 1, n. 2 (6 novembre 2009): 74–99. http://dx.doi.org/10.3390/toxins1020074.

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35

Mustafa, S. M. D. "Cyclopiazonic Acid Induces Contractions in Ovine Tracheal Smooth Muscle". Pharmacy and Pharmacology Communications 6, n. 10 (1 ottobre 2000): 459–63. http://dx.doi.org/10.1211/146080800128735511.

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36

Burdock, G. A., e W. G. Flamm. "Review Article: Safety Assessment of the Mycotoxin Cyclopiazonic Acid". International Journal of Toxicology 19, n. 3 (maggio 2000): 195–218. http://dx.doi.org/10.1080/10915810050074964.

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Abstract (sommario):

Cyclopiazonic acid (CPA) is an indol-tetramic acid mycotoxin and is produced by the nearly ubiquitous molds, Aspergillus and Penicillium. CPA produced by these molds has been identified in a number of food sources (including, but not limited to, grain, legumes, meat, milk, and cheese) and from parasitic infections of man and other animals. Few incidents of CPA mycotoxicoses have been reported because of the benign nature of the intoxication, the small amounts present, and its effects may be disguised with concurrent aflatoxicosis (some toxicity data may have been generated using aflatoxin-contaminated CPA). CPA is absorbed in the gastrointestinal tract and following oral administration; it has a half-life of approximately 30 hours and is excreted largely unchanged in the urine and feces. Cyclopiazonic acid is not considered to be a potent acute toxin as its oral LD50 in rodents is in the range of 30 to 70 mg/kg. Multiple dose studies also show a range of effects in several species and among mammalian models, the pig appears to be the most sensitive with a no-observable-effect level (NOEL) in the range of 1.0 mg/kg/day. The preponderance of evidence from the rat and other test animals supports this dose as a defensible estimate of a no effect level. The target organs of CPA toxicity appear to be muscle, hepatic tissue, and spleen, with a localization in the former, although a more apparent toxic change in the latter two. The toxicity and symptoms of CPA poisoning can be attributed to its ability to alter normal intracellular calcium flux through its inhibition of the reticular form of the Ca2+-ATPase pump. CPA was not teratogenic in mice. CPA is not considered a carcinogen and the weight of evidence militates against its characterization as a mutagen. Despite CPA-induced pathological changes ascribed to the spleen or bursa of Fabricius, there does not appear to be an effect on the immune system. In vitro studies imply a potential immunomodulatory effect of CPA, but in all of those reports very high concentrations of CPA were required and none of these findings have been supported with in vivo studies. Therefore, based on a NOEL of 1 mg/kg/day and accounting for species variation, an appropriate acceptable daily intake (ADI) would be approximately 10 μg/kg/day or 700 μg/day. In the context of human exposure, if the uppermost limit of CPA found in cheese is 4 μg/g and the average individual consumes 50 g of cheese daily, this allows an intake of 200 μg, less than one third of a traditionally established ADI.

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37

de Waal, E. J. "Letter to the Editor—Safety Assessment of Cyclopiazonic Acid". International Journal of Toxicology 21, n. 5 (settembre 2002): 425–27. http://dx.doi.org/10.1080/10915810290096658.

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38

Norred, William P., Richard J. Cole, Joe W. Dorner e John A. Lansden. "Liquid Chromatographic Determination of Cyclopiazonic Acid in Poultry Meat". Journal of AOAC INTERNATIONAL 70, n. 1 (1 gennaio 1987): 121–23. http://dx.doi.org/10.1093/jaoac/70.1.121.

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Abstract (sommario):

Abstract A liquid chromatographic procedure has been developed for the determination of cyclopiazonic acid (CPA) in poultry meat. CPA is extracted from ground meat with chloroform-methanol (80 + 20), partitioned into 0.1 N sodium hydroxide, acidified, and extracted into dichloromethane. An interfering component of meat is removed by transferring the dichloromethane extract to a minicolumn containing silica gel and washing the column with petroleum ether and chloroform. CPA is eluted with methanol-acetic acid (99 + 1), and subjected to ligand-exchange liquid chromatography. Recovery of CPA from 40 separate samples of meat spiked with CPA at levels from 0.016 to 15.6 ppm was 70.4 + 14.1%. Analysis of meat from a chicken orally dosed with 10 mg CPA/kg body weight revealed that 14.5% of the dose was in muscle 48 h after administration.

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39

LAHOURATATE, P. "Cyclopiazonic acid: A tool to investigate sarcoplasmic reticulum activity". Journal of Molecular and Cellular Cardiology 24 (luglio 1992): 43. http://dx.doi.org/10.1016/0022-2828(92)93451-o.

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40

Jiang, Minghua, Senhua Chen, Jing Li e Lan Liu. "The Biological and Chemical Diversity of Tetramic Acid Compounds from Marine-Derived Microorganisms". Marine Drugs 18, n. 2 (15 febbraio 2020): 114. http://dx.doi.org/10.3390/md18020114.

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Abstract (sommario):

Tetramic acid (pyrrolidine-2,4-dione) compounds, isolated from a variety of marine and terrestrial organisms, have attracted considerable attention for their diverse, challenging structural complexity and promising bioactivities. In the past decade, marine-derived microorganisms have become great repositories of novel tetramic acids. Here, we discuss the biological activities of 277 tetramic acids of eight classifications (simple 3-acyl tetramic acids, 3-oligoenoyltetramic acids, 3-decalinoyltetramic acid, 3-spirotetramic acids, macrocyclic tetramic acids, N-acylated tetramic acids, α-cyclopiazonic acid-type tetramic acids, and other tetramic acids) from marine-derived microbes, including fungi, actinobacteria, bacteria, and cyanobacteria, as reported in 195 research studies up to 2019.

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41

Benkhemmar, O., F. Gaudemer e I. Bouvier-Fourcade. "Heterokaryosis between Aspergillus oryzae cyclopiazonic acid-defective strains: method for estimating the risk of inducing toxin production among cyclopiazonic acid-defective industrial strains." Applied and Environmental Microbiology 50, n. 4 (1985): 1087–93. http://dx.doi.org/10.1128/aem.50.4.1087-1093.1985.

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42

BAILLY, J. D., C. TABUC, A. QUÉRIN e P. GUERRE. "Production and Stability of Patulin, Ochratoxin A, Citrinin, and Cyclopiazonic Acid on Dry Cured Ham". Journal of Food Protection 68, n. 7 (1 luglio 2005): 1516–20. http://dx.doi.org/10.4315/0362-028x-68.7.1516.

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Abstract (sommario):

Toxinogenic fungal species can be isolated from dry cured meat products, raising the problem of the direct contamination of these foods by mycotoxins known to be carcinogenic or potent carcinogens. Because the contamination of a food by mycotoxins can be considered a balance between production and degradation, the stability of mycotoxins on dry cured meat was also investigated. This study focused on patulin, ochratoxin A, citrinin, and cyclopiazonic acid that can be produced by fungal species previously isolated from dry cured meat products sold on the French market. We demonstrated that neither patulin nor ochratoxin A was produced on dry meat by toxigenic strains, whereas relatively high amounts of citrinin and cyclopiazonic acid were found after a 16-day incubation period at 20°C (87 and 50 mg/kg, respectively). After direct contamination, the initial content of patulin rapidly decreased to become undetectable after only 6 h of incubation at 20°C. For both citrinin and ochratoxin A, the kinetics of decrease at 20°C was less rapid, and the two toxins presented half-lives of 6 and 120 h, respectively. By contrast, more than 80% of the initial contamination in cyclopiazonic acid was still found on ham after a 192-h incubation period. Toxin stability was not affected by storage at 4°C. These results suggest that growth of toxigenic strains of Penicillium has to be avoided on dry meat products.

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43

Holzapfel, CW, e FWH Kruger. "The Synthesis of Optically Pure β-Cyclopiazonic Acid, an Indolic Fungal Metabolite". Australian Journal of Chemistry 45, n. 1 (1992): 99. http://dx.doi.org/10.1071/ch9920099.

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Abstract (sommario):

The chiral synthesis of the fungal metabolite β- cyclopiazonic acid is described. The key step involves the use of the tricarbonylchromium complex of an N-protected L- tryptophan methyl ester as a substrate for the addition/oxidation method of substitution of its indole ring system.

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44

Jantrarotai, Wimol, e Richard T. Lovell. "Acute and Subchronic Toxicity of Cyclopiazonic Acid to Channel Catfish". Journal of Aquatic Animal Health 2, n. 4 (dicembre 1990): 255–60. http://dx.doi.org/10.1577/1548-8667(1990)002<0255:aastoc>2.3.co;2.

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45

FINOLI, CARLO, ANGELA VECCHIO, ANTONIETTA GALLI e LAURA FRANZETTI. "Production of Cyclopiazonic Acid by Molds Isolated from Taleggio Cheese". Journal of Food Protection 62, n. 10 (1 ottobre 1999): 1198–202. http://dx.doi.org/10.4315/0362-028x-62.10.1198.

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Abstract (sommario):

Twenty-seven strains of Penicillium were isolated from the rind of Taleggio, a typical Italian cheese, so that we could test their capacity to produce cyclopiazonic acid (CPA); all strains produced CPA. The production was strongly influenced by the strain variety and growth conditions. Strains incubated at 25°C for 7 days always produced CPA in mannitol broth, with concentrations ranging from 0.02 to 1 μg/ml, whereas only 33% of strains grown in yeast-extract broth produced CPA, with a maximum value of 0.1 μg/ml. In milk, maximum production (1.6 μg/ml) was observed after 14 days of incubation at 25°C. In order to evaluate the presence of the toxin and its capacity for migrating into the cheeses, the rind, the cheese near the rind, and the cores from six Taleggio cheeses were analyzed. CPA was present in five cheeses, with a maximum concentration of 0.25 mg/kg in one rind, and in one cheese, the toxin migrated to the core. A positive correlation between CPA production and surface mold was found.

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46

MARTINS, MARIA LÍGIA, e HERMÍNIA MARINA MARTINS. "Natural and In Vitro Coproduction of Cyclopiazonic Acid and Aflatoxins". Journal of Food Protection 62, n. 3 (1 marzo 1999): 292–94. http://dx.doi.org/10.4315/0362-028x-62.3.292.

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Abstract (sommario):

Eighty samples of animal feeds of different origins were screened for the natural co-occurrence of cyclopiazonic acid (CPA) and aflatoxins in Portugal. Forty-five strains of Aspergillus flavus were collected from those samples and studied for their ability to produce these mycotoxins, in vitro. CPA was detected by thin-layer chromatography using Erhlich's reagent for confirmation. Aflatoxins were determined by high-pressure liquid chromatography with postcolumn iodination. Only 5 of the 80 samples (6.2%) were naturally contaminated with cyclopiazonic acid (0.16 mg/kg) and 36 (45.0%) with aflatoxin B1 (AFB1) (from 0.001 to 0.016 mg/kg). An in vitro study of the 45 strains of A. flavus was performed in cracked corn at 25°C (water activity, aw = 0.96), incubated for 21 days to CPA production. For in vitro production of aflatoxins, the same substrate was incubated at 28°C for 14 days. Nineteen of the strains (42.2%) produced CPA (ranging from 0.5 to 1.45 mg of CPA/kg) and 23 of them (51.1%) produced AFB1 (from 0.001 to 0.844 mg/kg). Only 10 isolates (22.2%) produced both CPA and AFB1 (0.05 to 0.10 mg/kg and 0.001 to 0.230 mg/kg, respectively). Thirteen strains did not produce either CPA nor AFB1.

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47

Byrem, T. M., J. J. Pestka, F. S. Chu e G. M. Strasburg. "Analysis and pharmacokinetics of cyclopiazonic acid in market weight pigs." Journal of Animal Science 77, n. 1 (1999): 173. http://dx.doi.org/10.2527/1999.771173x.

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48

Hong, S. J., Hsiu-Chuan Liang e Ching-Jung Shen. "Dependence of cyclopiazonic-acid-induced muscle contractures on extracellular Ca2+". Canadian Journal of Physiology and Pharmacology 81, n. 12 (1 dicembre 2003): 1101–9. http://dx.doi.org/10.1139/y03-116.

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Abstract (sommario):

Inhibition of Ca2+ uptake by the sarcoplasmic reticulum decreases cytosolic Ca2+ clearance and also triggers Ca2+ influx in response to Ca2+ store depletion. The role of extracellular Ca2+ in the contractures evoked by cyclo piazonic acid (CPA) and thapsigargin (TG), Ca2+ pump inhibitors, was assessed in mouse diaphragm. At 3–100 µM, CPA elicited a rapid-onset contracture followed by a large elevation of muscle tone, which corresponded temporally to the monophasic slow contracture evoked by TG (1–30 µM). Irrespective of the differences in profiles, contractures were prevented and inhibited by the removal of extracellular Ca2+, but not by nicardipine and SK&F96365, blockers of voltage-gated (L-type) and receptor-operated Ca2+ channels. Mn2+ and Ni2+ preferentially depressed the fast-phase contracture, whereas long-term pretreatment with LY294002, U73122, and 2-aminoethoxydiphenylborance, inhibitors of phosphatidylinositol kinase, phospholipase C, and inositol trisphosphate receptors, suppressed the slow-phase contrac ture. When contracture was inhibited, the twitch response remained augmented and prolonged by CPA and TG, indicating that the inhibition was not due to malfunction of the contractile apparatus. For preparations incubated in Ca2+-free medium containing CPA, a monophasic fast upstroke of muscle tone developed as extracellular Ca2+ was restored. The results suggest that the bimodal contracture induced by CPA is mediated by the recruitment of distinct Mn2+- and U73122-sensitive Ca2+ entries. The ongoing two-component Ca2+ entries might merge if the muscle preparation was preconditioned with CPA in Ca2+-free medium to deplete cellular Ca2+ stores.Key words: thapsigargin, LY294002, U73122, sarcoplasmic reticulum, 2-aminoethoxydiphenylborane, inositol trisphosphate receptor.

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49

SMITH, E. E., L. F. KUBENA, C. E. BRAITHWAITE, R. B. HARVEY, T. D. PHILLIPS e A. H. REINE. "Toxicological Evaluation of Aflatoxin and Cyclopiazonic Acid in Broiler Chickens". Poultry Science 71, n. 7 (luglio 1992): 1136–44. http://dx.doi.org/10.3382/ps.0711136.

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50

Cole, Richard J., e Joe W. Dorner. "Biological Control of Aflatoxin and Cyclopiazonic Acid Contamination of Peanuts". Mycotoxins 1999, Suppl2 (1999): 70–73. http://dx.doi.org/10.2520/myco1975.1999.suppl2_70.

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