Mycotoxins sterigmatocystin

KELLER, N.P., KANTZ, N.J., ADAMS, T.A., Aspergillus nidulans verk is required for production of the mycotoxin sterigmatocystin, Appl. Environ. Microbiol, 1994,60, 1444-1450. 

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. 

The mycotoxins with the greatest potential risk to human and animal health as food and feed contaminants are AFs, trichothecenes, fiimonisins, zearalenone, ochratoxin A, and ergot alkaloids.109 Other mycotoxins such as cyclopiazonic acid, sterigmatocystin, gliotoxin, citrinin, penitrems, patulin, fusarin C, penicillic acid, and PR... 

Zhang RF, Chen CS, Yu L, Sun HL, Fu CG, Xu HD Aspergillus versicolor and sterigmatocystin might be related to genesis of gastric cancer. Abstract 7th Int Union of Pure and Applied Chemistry (lUPAC), International Symposium on Mycotoxins and Phytotoxins, Tokyo 1988. Dutton MF Fumonisins, mycotoxins of increasing importance Their nature and their effects. Pharmacol Ther 1996 70 137-161. 

There are a notable number of additional mycotoxins which are structurally related to sterigmatocystin (30). The structural details were generally arrived at by spectro-... 

Among several classes of compounds belonging to the group of mycotoxins, carcinogenic properties have been demonstrated only for three of them. These are aflatoxins and sterigmatocystin, inducing liver cancers, and ochratoxin A, implicated in the development of kidney cancers in experimental animals (Wakabayashi etal., 1991) ... 

Studies (Shreeve et al., 1979 Robinson et al., 1979 Prelusky et al., 1984) on the indirect contamination of milk with other mycotoxins such as ochra-toxin A, zearalenone, T-2 toxin, sterigmatocystin, and deoxynivalenone have indicated that contamination of milk with these mycotoxins does not represent a significant public health issue. 

Compared with the isoamylase activity, the activity of other hydrolytic enzymes (cellulase, lipase and protease) is very low (<0.06%) in the isoamylase enzyme preparation. When three batches of the isoamylase enzyme preparation were analysed for aflatoxins (Bi, B2, Gi and G2), sterigmatocystin, zearalenone and ochratoxin, none of these mycotoxins was detected. 

Sterigmatocystin (15) is both a carcinogenic hepatotoxin and a biosynthetic precursor to the important mycotoxin, aflatoxin, and, as such, its biosynthesis pathway has been studied quite extensively (607-608). This is purported to begin with a single C20 polyketide unit, which is folded in only one mode to form averufin (103) and then sterigmatocystin (15) (609). The authors provided evidence to support the identity of this compound through the synthesis of a common product from both it and from a... 

Fusarium toxins, also called trichothecenes. Other mycotoxins are also encountered but to a lesser extent, and consecutively they are of less concern for public authorities cyclotropiazonic acid, sterigmatocystin, pe-nitrem A, and tenuazonic acid. The structures of these mycotoxins are shown in Figures 1-10. 

Sterigmatocystin is very acutely toxic to humans and animals and hke aflatoxins acts as a hepatocarcinogen. According to the lARC, it is classified as a Group 2B carcinogen to humans. As one of the priorities in the dietary risk assessment, the European Food Safety Authority (EFSA) identified the need to gather a more complete set of data on the occurrence of this mycotoxin in foods. Maximum levels in foods are not currently set due to a lack of data from which to assess the associated health risks. 

Mycotoxins have been used extensively by Ueno and Kubota.These workers have found that 6 Penicillium toxins, 5 Aspergillus toxins, and 2 Fusa-rium toxins are positive in the rec-assays, including 8 mycotoxins that arc known carcinogens in animals citrinin, penicillic acid, patulin, (-)-luteoskyrin, (-l-)-rugulosin, aflatoxin Bi and Gi, and sterigmatocystin (Table 9). 

Llewellyn and 0 Rear (1978) examined 30 illicit marihuana products that were confiscated by Virginia law enforcement officials for the presence of mycotoxins. One-third of the laboratory samples exhibited mold growth, but no detectable levels of aflatoxins were found in any of the products tested. However, one product contained a substance similar to sterigmatocystin, a related mycotoxin produced by A. versicolor. 

Reiss, J. (1976). Mycotoxins in foods inhibition of the formation of mycotoxins (aflatoxins) and patulin and sterigmatocystin in whole wheat bread by sorbic acid and sorboyl palmitate. Dtsch Lebensm Rundsch, 72, 51-54. 

Sterigmatocystin (32) assumes great structural importance in mycotoxin chemistry, because it was the first characterized compound which contained the unique bisdihydrofuran functionality, in this case linked to a xanthone nucleus. The structure (Fig. 5) (Bullock et al., 1962) and absolute configuration were verified by X-ray crystallography (Fukuyama et al., 1975c, 1976). 

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