- Email: [email protected]
2385. Benzoquinones from beetles
NATURAL PRODUCTS
605
2385. Benzoquinones from beetles Shimkin, M. B., Gruenstein, M. & Meranze, D. R. (1971). Test for carcinogenic activity of benzoquinones in Long-Evans rats. Cancer Res. 31, 957. Quinones secreted by the flour beetle, Tribolium confusum, and his near relatives have been suspected of being carcinogenic (Ladisch, Proc. Penn. Acad. Sci. 1964, 38, 144; Ladisch et al. Nature, Lond. 1967, 215, 939 ; Ladisch et al. Proc. Penn. Acad. Sci. 1968, 42, 87). The question of their occurrence in flour and cocoa products is therefore of some importance. The two major quinones involved are 2-ethyl-p-benzoquinone (I) and 2-methyl-p-benzoquinone (II). Injections of I, II and tetritoxin (III), which is a 4:1 mixture of I and II isolated from T. confusum, were given to rats in tricaprylin solution in a subcutaneous dose of 3 mg every other week for four doses, then in a dose of 6 mg every other week for a further 16 doses. Controls were given injections of the solvent alone. All groups of animals, including the controls and an untreated group, developed turnouts from wk 66 onwards, but with no consistent pattern. There was no significant increase in tumour incidence in animals given I, II or III; 46 controls developed 11 tumours while 86 test rats mustered a total of 16. There were five fibrosarcomas among the treated rats, but there was also one among the 26 rats given solvent alone, There was no difference in the numbers of mammary tumours appearing in females. [While this type of subcutaneous study does not help us to decide whether, aesthetic considerations apart, we should eat cereal products in which beetles have lived, the possibility that insects present in flour, cocoa and other common foods may, like certain notorious moulds, be a source of toxic and perhaps even carcinogenic food contaminants is an interesting one.]
2386. The pecan peril outlined Doupnik, B., Jr. & Bell, D. K. (1971). Toxicity to chicks of Aspergillus and Penicillium species isolated from moldy pecans. Appl. Microbiol. 21, 1104. The toxic effects of ochratoxins isolated from cultures of Aspergillus ochraeeus (Cited in F.C.T. 1972, 10, 276) and of rubratoxins isolated from Penicillium rubrum cultures (ibid 1970, 8, 713) are well documented. Similarly, the possible hazard of aflatoxins produced in foodstuffs by related mould species is fully appreciated (ibid 1970, 8, 681). Preliminary investigations reported in the paper cited above suggest that much remains to be discovered about the optimal storage conditions for pecans (Carya illinoensis) to avoid the development of toxic mould metabolites. Examination of mouldy pecans harvested in 1966 and stored for 4 months at 16°C and > 80 ~ humidity revealed the presence of aflatoxins at a level of 75 ppb (b = 109). The most prevalent moulds isolated from the samples were A. chevalieri, A. flavus, A. niger, A. ochraceus, A. repens, Botryodiplodia theobromae, Epieoccum nigrum, P. citrinum, P. implicatum, P. funiculosum and a Pestalotia species. When groups of day-old chicks were fed 27 isolates from mouldy pecans with a protein supplement for 14 days, 13 had no effect, eight (including A. chevalieri, A. flavus, A. repens and P. funiculosum) reduced growth rates, and six (isolates of A. oehraceus and of a complex of P. citrinum and P. implieatum)were lethal. Detectable quantities of aflatoxins were found in the two toxic isolates of A. flavus and
605
2385. Benzoquinones from beetles Shimkin, M. B., Gruenstein, M. & Meranze, D. R. (1971). Test for carcinogenic activity of benzoquinones in Long-Evans rats. Cancer Res. 31, 957. Quinones secreted by the flour beetle, Tribolium confusum, and his near relatives have been suspected of being carcinogenic (Ladisch, Proc. Penn. Acad. Sci. 1964, 38, 144; Ladisch et al. Nature, Lond. 1967, 215, 939 ; Ladisch et al. Proc. Penn. Acad. Sci. 1968, 42, 87). The question of their occurrence in flour and cocoa products is therefore of some importance. The two major quinones involved are 2-ethyl-p-benzoquinone (I) and 2-methyl-p-benzoquinone (II). Injections of I, II and tetritoxin (III), which is a 4:1 mixture of I and II isolated from T. confusum, were given to rats in tricaprylin solution in a subcutaneous dose of 3 mg every other week for four doses, then in a dose of 6 mg every other week for a further 16 doses. Controls were given injections of the solvent alone. All groups of animals, including the controls and an untreated group, developed turnouts from wk 66 onwards, but with no consistent pattern. There was no significant increase in tumour incidence in animals given I, II or III; 46 controls developed 11 tumours while 86 test rats mustered a total of 16. There were five fibrosarcomas among the treated rats, but there was also one among the 26 rats given solvent alone, There was no difference in the numbers of mammary tumours appearing in females. [While this type of subcutaneous study does not help us to decide whether, aesthetic considerations apart, we should eat cereal products in which beetles have lived, the possibility that insects present in flour, cocoa and other common foods may, like certain notorious moulds, be a source of toxic and perhaps even carcinogenic food contaminants is an interesting one.]
2386. The pecan peril outlined Doupnik, B., Jr. & Bell, D. K. (1971). Toxicity to chicks of Aspergillus and Penicillium species isolated from moldy pecans. Appl. Microbiol. 21, 1104. The toxic effects of ochratoxins isolated from cultures of Aspergillus ochraeeus (Cited in F.C.T. 1972, 10, 276) and of rubratoxins isolated from Penicillium rubrum cultures (ibid 1970, 8, 713) are well documented. Similarly, the possible hazard of aflatoxins produced in foodstuffs by related mould species is fully appreciated (ibid 1970, 8, 681). Preliminary investigations reported in the paper cited above suggest that much remains to be discovered about the optimal storage conditions for pecans (Carya illinoensis) to avoid the development of toxic mould metabolites. Examination of mouldy pecans harvested in 1966 and stored for 4 months at 16°C and > 80 ~ humidity revealed the presence of aflatoxins at a level of 75 ppb (b = 109). The most prevalent moulds isolated from the samples were A. chevalieri, A. flavus, A. niger, A. ochraceus, A. repens, Botryodiplodia theobromae, Epieoccum nigrum, P. citrinum, P. implicatum, P. funiculosum and a Pestalotia species. When groups of day-old chicks were fed 27 isolates from mouldy pecans with a protein supplement for 14 days, 13 had no effect, eight (including A. chevalieri, A. flavus, A. repens and P. funiculosum) reduced growth rates, and six (isolates of A. oehraceus and of a complex of P. citrinum and P. implieatum)were lethal. Detectable quantities of aflatoxins were found in the two toxic isolates of A. flavus and