Secondary metabolites patulin

Paterson, R. R. M. (2004). The isoepoxydon dehydrogenase gene of patulin biosynthesis in cultures and secondary metabolites as candidate PCR inhibitors. Mycol. Res. 108, 1431-1437. 

Mycotoxins are toxic secondary metabolites produced by fungi growing within or on foods. They can be a serious threat to human and animal health (Nagler el al., 2001). Table 11.4 details mycotoxins associated with soft drinks and fruit juice manufacture and raw materials. Patulin is the most common mycotoxin associated with fruit juice, particular ly apple juice (Pitt Hocking, 1997). It commonly occurs if juice is produced from stored apples. Mould growth in infected apples increases with time, raising levels of patulin. The use of windfall apples for juice is also a factor. Avoidance of windfall apples, filtration of juice and pressing quickly after harvest are all methods to reduce the incidence of patulin in juice. Patulin can be destroyed by fermentation to cider or by the addition of ascorbic acid (Marth, 1992). Within Europe, the European Union has set a limit of 50 ig/kg for patulin in both apple juice and cider. A recent survey of apple products in Chile found that 28% of samples of juice and concentrate exceeded this limit (Canas Aranda, 1996). 

Andersen, B., Smedsgaard, J., and Frisvad, J.C. 2004. Penicillium expansum Consistent production of patulin, chaetoglobosins, and other secondary metabolites in culture and their natural occurrence in fruit products. J. Agric. Food. Chem. 52, 2421-2428. 

Penicillium expansum consistent production of patulin, chaetoglobosins and other secondary metabolites and their natural occurrence in fruit products,... 

Andersen B, Smedsgaard J, Frisvad JC (2004) Penicillium expansum Consistent Production of Patulin, Chaetoglobosins, and Other Secondary Metabolites in Culture and Their Natural Occurrence in Fruit Products. J Agric Food Chem 52 2421... 

The line between catabolic and anabolic activity is as nebulous as that between primary and secondary metabolism. The mycotoxins aflatoxin and patulin give every appearance of being catabolic in nature (Haslam, 1986). Many secondary metabolites possess elements of structure that directly parallel those observed in the catabolism of primary metabolites such as a-amino acids (Haslam, 1986). 

The relatively high incorporations of tracer molecules into secondary metabolites in micro-organisms has enabled detailed studies to be made of the biosynthesis of the fungal metabolites patulin (10) and multicolic acid (79). Carbon-14 work has demonstrated the polyketide origin of patulin, and the biosynthesis of multicolic acid from acetate has been studied by C-n.m.r. spectroscopy. The biosynthesis of patulin has been investigated extensively at the enzymology level. In the first... 

The biosynthesis of patulin (10) has been studied extensively, since the molecule represents a relatively simple model system in which to examine the detailed enzymology of polyketide biosynthesis. Patulin is biosynthesized by the fungus Penicillium patulum via an oxidative pathway from 6-methylsalicylic acid (188) which is synthesized from acetyl-CoA and malonyl-CoA. The major pathway from (188) and the biosynthetic relationships of the phenolic secondary metabolites of P. patulum are... 

Roquefortine C was often accompanied by a structurally related mycotoxin isofumigaclavine A (12-98). P. roqueforti molds may occasionally produce patulin, citrinin (12-99), penicillic acid (12-100), the so-called PR-toxin (12-101) and certain other toxins that have been implicated in incidents of mycotoxicoses. However, PR toxin is not stable in cheese and breaks down to the less toxic PR imine (12-101). Other secondary metabolites ofP. roqueforti found in blue cheeses are andrastins A-D with skeletons of ent-5a,lA -androstane. In European blue cheeses, the content of andrastin A (12-102) ranged from 0.1 to 3.7 mg/kg and contents of andrastins B, C and D were on average five times lower. The most significant biological activity of adrastins is the ability to inhibit the enzyme farnesyltransferase, an enzyme that catalyses the transfer of farnesyl residue from farnesyl diphosphate to proteins. It is a part of the apparatus carrying post-translational modification of proteins in... 

Although nutrient restriction is also conducive to the formation of spores (conidia) in P. urticae, there is no direct connection with patulin synthesis (Sekiguchi and Gaucher, 1977). Equally, in other species where the patulin pathway exists alongside independent pathways to other secondary metabolites, such as byssochlamic acid, the optimum conditions for one pathway may be significantly different from those for the other (Escoula, 1975). 

Patulin (1) and penicillic acid (2) are secondary metabolites which are synthesized primarily by Penicillium and Aspergillus species. The patulin isolated has been given various names patulin, claviformin, clavacin, clavatin, expansin, leucopin, mycoin C, penicidin, and tercinin (Florey et aL, 1949 Scott, 1974 Singh, 1967 Wilson and Hayes, 1973 Wilson, 1976). Patulin and penicillic acid are produced by different fungal species, but the biological reactions leading to these two natural products are very similar. In this chapter, only the physical properties of patulin and penicillic acid relevant to biosynthetic studies will be discussed. 

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