Aflatoxins B! and

The keto-carbonyl C signal at 5c = 200.9 would only fit the aflatoxins B, and M,. In the C NMR spectrum an enol ether-C// fragment can also be recognised from the chemical shift value of 5c = 145.8 and the typical one-bond coupling constant Jch = 196 Hz the proton involved appears at Sh = 72, as the CH COSY plot shows. The H triplet which belongs to it overlaps with a sing-... 

MC=3-methylcholanthrene DMAB - 3-methy1-4-dimethy1amino-azobenzene AAF = 2-acety1aminofluorene MNU = 1 methyl-1-nitrosourea DMBA 7,12 dimethylbenz(a)anthracene DMH - 1,2 dimethylhydrazine BMA bis(2-oxopropyl) nitrosamine Afl B = aflatoxin B and AZM azoxymethane. 

The keto-carbonyl 13C signal at 8C = 200.9 would only fit the aflatoxins B and Mt. In the, 3C NMR spectrum an enol cther-C// fragment can also be recognised from the chemical shift value of... 

Our initial studies using the kits were disappointing, invariably resulting in modifications of the kits themselves and changes in protocols for use of the kits. Following this initial phase of work, we decided one kit was ready for collaborative study. This first collaborative study involved use of the Neogen Agri-Screen kit. The antibodies have specific ability to bind aflatoxin B, and very low cross reactivity to aflatoxins B, G, and G,. This kit contains Antibody-coated microtiter wells Aflatoxin standard solution Dilution buffer (Tris)... 

As discussed, aflatoxins are genotoxic and carcinogenic, and for substances of this type, there is no threshold below which no harmful effect is observed. Subsequently, no tolerable daily intake has been set by the JECFA or any other international or national authority. Limits for foods are set as low as reasonably achievable. The current legislation in the European Union includes a maximum level of 2 pg/kg for aflatoxin B, and 4 pg/kg aflatoxin B1 B2, Gi, and G2 for dried fruits and products processed thereof, intended for direct human consumption or as an ingredient in foodstuffs. 

It has been found that melanoidins are antagonistic to mutagens and such carcinogens as aflatoxin B and N-methyl-N -nitro-AT-nitrosoguanidine and various heterocyclic mutagens. High-molecular-weight fractions of melanoidin are the most effective in this respect." ... 

Caulfield, M. J., G. R. Burleson, and M. Pollard. 1979. Ozonation of mutagenic and carcinogenic alkylating agents, pesticides, aflatoxin B, and benzidine in water. Cancer Res. 39 2155-2159. 

Table I. Levels of AF-Albumin Adducts in Rat Plasma following Treatment with Aflatoxins B, and 6,...

Aflatoxin has also been found to be degraded by various Rhizopus spp. to an intermediate metabolite previously reported in A. flavus as aflatoxin B, and in A parasiticus as parasiticol. Ciegler et al. [59] screened over 100 microorganisms for their ability to either d ade or... 

While the aflatoxins B and G are major compounds of the fungus Aspergillus flavus, there are also minor aflatoxin constituents from this organism, e.g. hydroxylated derivatives of aflatoxin Bi (1) and B2 (2), the so-called milk-toxins . Ml (5) and M2 (6), which bear a hydroxy group at the junction of the two furan rings 19). They are called mOk toxins , because they are metabolites of aflatoxin Bi (1) and B2 (2), formed when cows get fed with contaminated foodstuffs. The toxins are then contained in the cow s milk. Other aflatoxins have a hydroxy group instead of... 

More than 350 mycotoxins have been identified either from food or from laboratory culture media. The main mycotoxins (Table 1) of concern for the safety of consumers are aflatoxins (aflatoxins B and G, aflatoxin Ml), ochratoxin A, patulin, fumonisins, zearalenone, and deoxynivalenol (DON) and other... 

Aflatoxins B and G in peanut butter, pistachios, fig paste, and paprika Methanol 80% and defatting with pure hexane Immunoaffinity cleanup prior to LC coupled to fluorescence detector and postcolumn derivatization by using iodination or bromination 0.2 ng per kg of aflatoxin B1 0.4 pg per kg for sum of aflatoxins B and G 85-100... 

Cells were exposed simultaneously to methylcholanthrene, aflatoxin B, and 3-aminobenzamide for a 24 h period... 

Table 22. Hepatocarcinoma Incidence in Trout Fed Aflatoxin B] and and Methyl Sterculate (MS) ...

Table 12.22 Changes in aflatoxin B, and M, levels during processing of contaminated materials. ...

A most promising approach to controlling or minimizing aflatoxin contamination is due to recent advances in the processing of the seed extracts. It is now possible to efficiently remove aflatoxins to levels below that of public health concern. Figure 10 shows a typical result for a comparison of the levels of aflatoxins B] and B2 in hygienically treated seed extracts versus non-hygienically treated extracts. 

Mycotoxin analyses for the Pamlico county samples were shown in Table 1. Calculated ZE concentrations in the original (reconstituted) samples averaged 53 ng/g. Zearalenone in the fractions buoyant in the brine averaged 320 ng/g. There was no detectable ZE in the nonbuoyant grain from these nine samples. Deoxynivalenol was detected in only one of the nine samples, but the segregation pattern was similar to that of ZE. Aflatoxins B- and B2 did not segregate into the buoyant fractions (Table 1). Moreover, there was no correlation between AF concentration and either ZE or DON. 

FIGURE 6.3 Chemical structure of the different types of aflatoxins. Aflatoxins B and G occur in infested grains, whereas M aflatoxins are found in the milk of lactating animals fed contaminated feedstuffs. 

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