macrocyclic trichothecene mycotoxins: Topics by WorldWideScience.org

Spices Mycobiota and Mycotoxins Available in Saudi Arabia and Their Abilities to Inhibit Growth of Some Toxigenic Fungi

Possible health risks associated with occupational inhalation of mycotoxin-containing dust remain largely unknown, partly because methods for mycotoxin detection are not sensitive enough for the small...Full Text Available

KoreaScience (Korea)

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2007-06-01

Mycotoxins in fungal contaminated samples of animal feed from western Canada, 1982-1994.

Enantioselective Fluorescent Recognition of Chiral Acids by Cyclohexane-1,2-diamine-Based Bisbinaphthyl Molecules

Feed samples from 94 cases involving fungal contamination and suspected mycotoxicosis of farm animals in western Canada were examined during 1982-1994 to assess the incidence of mycotoxins. Samples...Full Text Available

1997-01-01

Infection by mycotoxigenic fungal species and mycotoxin contamination of maize grain in Umbria, central Italy

The cyclohexane-1,2-diamine-based bisbinaphthyl macrocycles (S)-/(R)-5 and their cyclic and acyclic analogs are synthesized. The interactions of...Full Text Available

2007-06-22

British Library Electronic Table of Contents (United Kingdom)

Surveys were carried out in 2006 and 2007 in Umbria (central Italy) to evaluate the presence of mycotoxigenic fungi and mycotoxins in maize grain sampled at harvest. Fusarium spp., were the most abundant species detected in maize kernels, followed by Aspergillus species of sections Flavi and Nigri and by Penicillium spp. Among Fusarium species, F. verticillioides was the most prevalent species, as detected by PCR directly on the kernels and on the fungi isolated from the kernels, followed by F. proliferatum and F. subglutinans. Fumonisins were the predominant mycotoxins with values, on average, of 4.3 and 5.7mgkg-1, in 2006 and 2007, respectively, with a maximum of 76.3mgkg-1 in the second year. Deoxynivalenol ranged from 0.2 to 3.98mgkg-1 in 2006 (average 1.04mgkg-1) and from undetectable...

2011-01-01

Indole-Diterpene Gene Cluster from Aspergillus flavus

Fungal spores: hazardous to health?

Aflatrem is a potent tremorgenic mycotoxin produced by the soil fungus Aspergillus flavus and is a member of a large structurally diverse group of secondary metabolites known as indole-diterpenes....Full Text Available

2004-11-01

Alleged Mycotoxicosis in Swine: Review of a Court Case

Fungi have long been known to affect human well being in various ways, including disease of essential crop plants, decay of stored foods with possible concomitant production of mycotoxins, superficial...Full Text Available

1999-06-01

The chemistry of the p-block elements with thioether, selenoether and telluroether ligands.

Vomition and diarrhea in feeder pigs, and signs of hyperestrogenism in sows and pregnant gilts in a large swine operation were thought to be caused by mycotoxins. Various toxicoanalytical tests performed...Full Text Available

1981-05-01

Science.gov (United States)

The synthesis and structures of acyclic and macrocyclic thio-, seleno- and telluro-ether complexes of the metallic and metalloid elements of Groups 13-16 reported since 2000 are described. The diverse structures range from discrete monomers through to infinite 1-, 2- or 3-D polymers. The coordination chemistry in this area is quite different to familiar d-block chemistry and the underlying factors are explored. PMID:21706103

2011-06-27

Synthesis, crystal structure and spectroscopic studies of copper(II) complex of C-meso-1,5,8,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane

British Library Electronic Table of Contents (United Kingdom)

Copper(II) complex coordinated with cyclam-type macrocyclic tetramine, C-meso-1,5,8,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane (2Cdmc) has been synthesized and characterized by single crystal X-ray crystallographic analysis and UV?Vis absorption spectra. Solved molecular structure of [Cu(2Cdmc)(H2O)]Cl2?2H2O (1) revealed that macrocyclic ligand 2Cdmc was in the most stable trans-III structure, but the C-methyl groups of 2Cdmc adopted energetically unfavorable axial configuration (C-axial). This complex 1 is the second example of complex of cyclam-type tetramine with only axially oriented C-methyl groups. This complex adopted five-coordinated square-pyramidal geometry with one water molecule occupying one of the two apical sites. Network of hydrogen bonds involving counter anions (Cl?...

2011-01-01

Solution conformations of CaCl sub 2 and Ca(NO sub 3 ) sub 2 complexes of chiral tetramethyl 18-crown-6 macrocycles: A 1D and 2D sup 1 H and sup 13 C NMR investigation

Progress and challenges in the discovery of macrofilaricidal drugs

One- and two-dimensional NMR techniques have been used to investigate the solution structures of (2S,6S,11S,15S)-2,6,11,15-tetramethyl-1,4,7,10,13,16-hexaoxacyclooctadecane (I) and (2R,3R,11R,12R)-2,3,11,12-tetramethyl-1,4,7,10,13,16-hexaoxyacyclooctadecane (II) macrocycle complexes of CaCl{sub 2} and Ca(NO{sub 3}){sub 2} in CDCl{sub 3}. Previous chiroptical studies of these and similar crown complexes by circularly polarized luminescence (CPL), total luminescence (TL), and circular dichroism (CD) spectroscopy have shown that the macrocycle asymmetric carbons in these complexes constrain the ring such that the sense of the ring twist in the S chiral ring complexes is opposite to that in the R chiral ring complexes. These studies have also shown that there is an added chirality element in the di- and trivalent (alkaline earth and lanthanide metal, respectively) nitrate complexes of I and II associated with the twist of the nitrate anions ...

1989-10-04

British Library Electronic Table of Contents (United Kingdom)

Control of human filarial infections currently depends on chemotherapeutic strategies predominantly directed at microfilariae. Doxycycline therapy in an extended daily dose regimen sterilizes and kills adult stages, but the utility of this drug for routine field use remains an issue of concern. No macrofilaricidal drugs with efficacy after one or two doses are available for use, delaying the achievement of the elimination or eradication of onchocerciasis and lymphatic filariasis. Moxidectin, a macrocyclic lactone, is currently in clinical trials for onchocerciasis. A few other drugs that have already been approved for use in veterinary practice or in human medicine for other indications are available for investigation. Early drug discovery pipelines are poorly populated and the process of ...

2011-01-01

Endophytic fungus Trichothecium roseum LZ93 antagonizing pathogenic fungi in vitro and its secondary metabolites

British Library Electronic Table of Contents (United Kingdom)

The endophytic fungus Trichothecium roseum LZ93 from Maytenus hookeri was found to antagonize other pathogenic fungi in vitro. To identify which compound contributed substantially to the antagonism, we fermented the strain and purified its fermentation products. Eleven compounds were obtained, including two trichothecenes, five rosenonolactones, two cardiotonic cyclodepsipeptides, and two sterols. Compound 11?-hydroxyrosenonolactone (1) was assigned according to 1D and 2D-NMR data for the first time. At the same time, the 1H and 13C-NMR assignments for 6?-hydroxyrosenonolactone (2) were revised. Of all of them, only trichothecin (6) showed strong antifungal activity. Based on our observations of the antagonistic activity and the other experimental results, we suggest that the antifungal co...

2010-01-01

A comparison of hepatic in vitro metabolism of T-2 toxin in rats, pigs, chickens, and carp

British Library Electronic Table of Contents (United Kingdom)

T-2 toxin, a highly toxic member of the type-A trichothecenes, is produced by various Fusarium moulds that can potentially affect human health. It is strongly cytotoxic for human hematopoietic progenitors. Alimentary toxic aleukia (ATA), a disease typically associated with human, is primarily induced by T-2 toxin. A comparison of the metabolism of T-2 toxin incubated with hepatocytes of rats, piglets, chickens, and the hepatic subcellular fractions (microsomes and cytosol) of piglets, chickens, rats, and carp (common carp and grass carp) was carried out. The activities of the recombinant pig CYP3A29 on the transformation of T-2 and HT-2 toxins were preliminary studied. Metabolites were identified by novel LC/MS-IT-TOF. Qualitative similarities and differences across the species were observ...

2011-01-01

Confirmatory analysis method for zeranol, its metabolites and related mycotoxins in urine by liquid chromatography-negative ion electrospray tandem mass spectrometry

Spin transition in octahedral metal complexes containing tetraazamacrocyclic ligands

The determination of the banned anabolic substance zeranol and the metabolites taleranol and zearalanone in bovine urine is complicated by the occurrence of the structurally-related mycotoxin zearalenone and the corresponding {alpha}- and {beta}-zearalenol metabolites which possess similar estrogenic properties. A liquid chromatography-negative ion electrospray tandem mass spectrometric method is presented for the confirmatory analysis of all six resorcylic acid lactones ('zeranols') in urine samples using deuterium-labelled internal standards. The method was validated as a confirmatory method for bovine urine samples according to new draft EU guidelines and showed good precision and linearity, and CC{alpha} and CC{beta} values of 0.02-0.30 and <1.0 ng ml{sup -1}, respectively. The applicability was demonstrated by comparing the results of an incurred sample with previous results on the same sample obtained by gas chromatography high ...

2002-11-25

British Library Electronic Table of Contents (United Kingdom)

This review focusses on spin crossover complexes with octahedral metal ions which are bound to a tetraazamacrocyclic ligand and additionally either to two monodentate ligands or to one bidentate ligand. Macrocyclic ligands with a sufficiently large ring size prefer to coordinate to metal ions in an equatorial fashion yielding trans-octahedral coordination environments. In contrast, twelve-membered tetraazamacrocycles with high steric rigidity, such as 2,11-diaza[3.3](2,6)pyridinophanes or 2,11-dithia[3.3](2,6)pyridinophane, are prone to form cis-octahedral complexes. While the electronic and the steric properties of the coordinated tetraazamacrocycle in trans-octahedral complexes are very likely responsible for the paucity of observed spin transitions, the cis-octahedral coordination mode ...

2009-01-01

Micellized sequestered silver atoms and small silver clusters

Azathia crown ethers carrying pyrene pendant as receptor molecules for metal sensor systems

Pulse radiolysis was used to examine the nature of the silver species obtained when an aqueous solution containing sequestered Ag"+ ions was reduced by hydrated electrons in the presence of a surfactant macrocyclic crown ether, labeled L, and/or a maltoside surfactant. The initially formed product is the Ag"0(L) species which rapidly loses its ligand (half-life #<=#5 #mu#s) and reacts with another Ag"+(L) ion to form Ag_2"+(L). The latter species decays by a bimolecular process to form the Ag_4"2"+(L)_n species at a faster rate than its ligand free analogue. Ultimately, colloidal metallic silver, (Ag)_n, forms which is stabilized by the surfactant moieties. No long-term stability to the reduced monomolecular species could be obtained.

Abiotic systems for the catalytic treatment of solvent-contaminated water

A series of crown ethers carrying a pyrene group with nitrogen-sulfur donor atoms, that differ in having three, four and five sulfur atoms in the macrocycle was designed and synthesized by the reaction of the corresponding macrocyclic compound and 1-bromomethylpyrene. The influence of metal cations such as Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+ and Al3+ on the spectroscopic properties of the ligands was investigated in acetonitrile-dichloromethane (1:1) by means of absorption and emission spectrometry. Absorption spectra show isosbestic points in the spectrophotometric titration of Fe2+, Zn2+, Cu2+, Pb2+ and Hg2+. The results of spectrophotometric titration experiments disclosed the complexation compositions and complex stability constants of the novel ligands with Fe2+, Zn2+, Cu2+, Pb2+ and Hg2+ cations. The monoazatetrathia crown ether showed good sensitivity for Cu2+ with linearity in the range 5.0x10-7-2.5x10-6 M and ...

2011-04-01

T-2 mycotoxin inhibits mitochondrial protein synthesis

Three abiotic systems are described that catalyze the reductive dehalogenation of heavily halogenated environmental pollutants, including carbon tetrachloride, trichloroethene, and perchloroethene. These systems include (a) an electrolytic reactor in which the potential on the working electrode (cathode) is fixed by using a potentiostat, (b) a light-driven system consisting of a semiconductor and (covalently attached) macrocycle that can accept light transmitted via an optical fiber, and a light-driven, two-solvent (isopropanol/acetone) system that promotes dehalogenation reactions via an unknown mechanism. Each is capable of accelerating reductive dehalogenation reactions to very high rates under laboratory conditions. Typically, millimolar concentrations of aqueous-phase targets can be dehalogenated in minutes to hours. The description of each system includes the elements of reaction mechanism (to the extent known), typical kinetic data, and a discussion of the ...

1996-12-31

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Effect of butylated hydroxytoluene pretreatment on the excretion, tissue distribution and DNA binding of (/sup 14/C)aflatoxin B1 in the rat

The authors investigated the effect of T-2 toxin on rat liver mitochondrial protein synthesis. Isolated rat liver mitochondria were supplemented with an S-100 supernatant from rat liver and an external ATP-generating system. An in-vitro assay employing cycloheximide, and inhibitor of cytoplasmic protein synthesis, and chloramphenicol, and inhibitor of mitochondrial protein synthesis, to distinguish mitochondrial protein synthesis from the cytoplasmic process. Amino acid incorporation into mitochondria was dependent on the concentration of mitochondria and was inhibited by chloramphenicol. The rate of uptake of tritium leucine into mitochondrial protein was unaffected by the addition of T-2 toxin and was not a rate-limiting step in incorporation. However, 0.02 micrograms/ml of T-2 toxin decreased the rate of protein synthesis inhibition correlated with the amount of T-2 toxin taken up by the mitochondria. While T-2 toxin is known to inhibit eukaryotic protein synthesis, this is the ...

1988-01-01

Comparative tissue distribution and excretion of orally administered ["3H]diacetoxyscirpenol (anguidine) in rats and mice

The effect of butylated hydroxytoluene (BHT) pretreatment (0.5% in the diet for 10 days) on the excretion, tissue distribution and DNA binding of orally administered (/sup 14/C)aflatoxin B1 (AFB1) was determined in male Fischer F344 rats. The amount of radioactivity excreted in the urine and feces by 24 hr was higher in BHT-treated rats than in controls. Treatment with BHT enhanced the excretion of water-soluble metabolites in the urine and in the large intestines plus feces at the earlier sampling times. The amount of radioactivity bound to hepatic nuclear DNA was six times less in the BHT-pretreated rats than in controls 6 hr after administration of the isotope. The half-lives of (/sup 14/C)DNA in the rat liver were 30 and 46 hr for control and BHT-pretreated rats, respectively. These results indicate that BHT pretreatment may protect the animal from the carcinogenic effects of AFB1 by enhancing the detoxification and excretion of the mycotoxin.

1985-06-01

Development of radioimmunometric assays and kits for non-clinical applications. Proceedings of a final research coordination meeting

A quantitative comparison of tissue distribution and excretion of an orally administered sublethal dose of [3H]diacetoxyscirpenol (anguidine) was made in rats and mice 90 min, 24 hr, and 7 days after treatment. Total recoveries of 95-100% were obtained. Approximately 90% of the dose was excreted in urine and feces during the first 24 hr with a feces:urine ratio of about 1:4.5 in both species. Carcass and tissue radioactivity dropped rapidly during the first 24 hr but remained relatively constant at low, but detectable, levels over the course of the experiment. Few substantive interspecies differences were noted in tissue distribution. At 90 min the highest percentage of dose was in tissues involved in sequestering diacetoxyscirpenol because of high body water/lipid content or the absorption, metabolism, or excretion of the toxin. The rank order of these tissues was generally stable over the course of the experiment. When data were expressed as specific radioactivity instead, the ...

Evaluation of fungal bio burden and mycotoxins presence in irradiated samples of medicinal plants purchased from wholesale and retail market

Immunoassays are versatile analytical techniques that had a leading role in various clinical applications, during the last four decades. The studies carried out by Rosalyn Yalow, Solomon Berson and Roger Ekins in the 1960s gave a breakthrough in the development of this novel analytical method. Sensitivity up to femtomolar concentrations, high specificity and universal application to different classes of molecular species made immunoassay a very useful tool in analytical investigation. The expertise acquired by immunochemists in producing antibodies against any antigen and the ability of radiochemists in labeling the antigens with "1"2"5I without affecting the active site are the two main factors responsible for the above development. There are concerns about the safety and health of humans due to the high-level contamination of environment by pesticides, industrial compounds and metals, anabolic steroids in milk and meat products, and presence of mycotoxins in food ...

2004-12-06