Carcinogen aflatoxin

The potent carcinogen aflatoxin B1 is activated by generation of an epoxide on a dihydrofuran moiety [43]. The potent MBIs contained in grapefruit juice and in the herbal medication St J ohn s Wort are furanocoumarin compounds [44—46]. A similar moiety is also incorporated in the HIV protease inhibitor L-754,394, a potent CYP3A4 MBI [47]. 

The carcinogenic aflatoxins, which are produced by Aspergillus flavus, may be present in infected peanuts and other foodstuffs.790 Like many other compounds that are carcinogenic or mutagenic, the aflatoxins are not unusually reactive chemically. 

The adverse health effects most readily associated with mycotoxin consumption are either acute or subchronic. Chronic effects, such as carcinogenicity, have been more difficult to directly relate to mycotoxin consumption. This is in spite of the fact that various data indicate that at least 45 mycotoxins are known to be either mutagenic or carcinogenic (1). The following mycotoxins may pose an adverse human health risk in respect to carcinogenicity aflatoxin, cyclochlorotine, griseofulvin, luteoskyrin, ochratoxin, patulin, penicillic acid, sterigmatocystin, T-2 toxin, and zearalenone. 

Structurally complex fused ring flm polyketides studied in this manner include the potent carcinogen aflatoxin Bi (7/ and its precursors averufin (8) and sterigmatocystin (9) (Scheme 4). The resulting couplings were consistent with... 

Bodine, A.B., C.A. Luer, S.A. Gangjee and C.J. Walsh. In vitro metabolism of the pro-carcinogen aflatoxin B1 by liver preparations of the calf, nurse shark and clearnose skate. Comp. Biochem. Physiol. 94C 447-453, 1989. 

The assoeiation of fungi with mammalian diseases came to the fore in 1960 with the diseovery of the aflatoxins (1.36). The death of turkeys from liver damage having been fed on groundnuts eontaminated with Aspergillus flavus led to the isolation of the highly carcinogenic aflatoxins. These developments are discussed in Chapter 9. It led to the awareness of the potential human health hazards from microbial metabolites and the implications of the presence of other mycotoxins in foodstuffs such as patulin in apple juice and the tri-chothecenes on corn. The development of analytical methods for the detection of mycotoxins has become an important aspect of food science. 

Carcinogens (aflatoxins, nitrosamines, polycyclic aromatic hydrocarbons... 

Hydroxylation of aflatoxin B. Biichi et al effected hydroxylation of the carcinogen aflatoxin Bi (1) to the metabolite (2) and the epimeric alcohol by... 

Van Herwaarden, A.E., Wagenaar, E., Kamekamp, B., Merino, G., Jonker, J.W. Schinkel, A.H. (2006) Breast cancer resistance protein (Brcp1/Abcg2) reduced systemic exposure of the dietary carcinogens aflatoxin B1, IQ and Trp-P-1 but also mediates their secretion into breast milk. Carcinogenesis 27,123-130. 

El-Nezami, H., Kankaanpaa, R, Safininen, S., Afiokas, J. (1998a). Ability of dairy strains of lactic acid bacteria to bind a common food carcinogen, aflatoxin Bj. Food and Chemical Toxicology, 36(4), 321-326. 

Using this approach, methods were established for the degradation of selected compounds in the following seven classes of chemical carcinogens aflatoxins, nitrosamines, nitrosamides, polycyclic aromatic hydrocarbons, hydrazines, haloethers and aromatic amines. A first study was also set up to investigate methods of degradation of some antineoplastic agents,... 

Iyer R, Coles B, Raney KD, Thier R, Guengerich FP, Harris TM (1994) DNA adduction by the potent carcinogen aflatoxin Bji mechanistic studies. J Am Chem Soc 116 1603 1609... 

The mycotoxins occur as natural contaminants in foodstuffs and include the carcinogenic aflatoxins. Although most of these compounds give molecular ions on El, extensive fragmentation occurs and a method was required which would detect a number of these substances in a mixture. 

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