Penicillium urticae, patulin

A simple lactone, parasorbic acid, from the fruit of mountain ash, inhibits seed germination and also has antibacterial action (75). Another such compound, patulin, is produced by several fungi, including Penicillium urticae, which produced large amounts of the substance when growing on wheat straw (76). 

Despite the apparent connections between formation of antibiotics and spores, it has become clear that antibiotic production is not obligatory for spore formation [192]. The most damaging evidence to the antibiotic-spore obligatory hypothesis is the existence of mutants which form no antibiotic but still sporulate. Such mutants have been found in the cases of bacitracin (Bacillus licheniformis), myco-bacillin (Bacillus subtilis), linear gramicidin (B. brevis), tyrocidine (B. brevis), gramicidin S (B. brevis), oxytetracycline (Streptomyces rimosus), streptomycin (S. griseus), methylenomycin A (Streptomyces coelicolor), and patulin (Penicillium urticae). 

Fig. 5.7. (a b) Biogenesis of patulin in Penicillium urticae (modified from Stoessl, 1981 used with permission of the copyright owner, Academic Press, New York). 

The ylidenebutenolide patulin (10) occupies a somewhat special place in organic chemistry. This structurally simple molecule, which is produced by the mold Penicillium urticae (synonym, P,patulum, P.flexuosum) was isolated independently by several groups of workers during the early 1940 s. It aroused immediate and widespread interest because of its potent antibiotic properties, but this interest evaporated almost as... 

Forrester, P. L, and G. M. Gaucher Conversion of 6-Methylsalicylic Acid into Patulin by Penicillium urticae. Biochemistry 11, 1102 (1972). 

It has been postulated that the antibiotic patulin, an unsaturated lactone produced by Penicillium urticae, is one of the most likely phytotoxins arising... 

Since this chapter was written, a new epoxide, isoepoxydon, was isolated (Sekiguchi and Gaucher, 1979 a,b Gaucher, 1979). Its structure was characterized as a partially reduced derivative of ( —)-phyllostine, and its stereochemistry was elucidated. Isoepoxydon was successfully converted into patulin by a cell-free preparation from Penicillium urticae, Isoepoxydon and phyllostine are interconvertible by an NADPH-dependent dehydrogenase. 

The microbial culprit organisms found to produce this environmental toxin are mostly Penicillium, Aspergillus, and Byssochlamys species (286-288) including P. patulum (289), P. urticae (290), P. claviforme (291), and P. expansum (292). While patulin (348) possesses antibiotic properties (293), it has not been investigated fully in this respect due to its toxic effects against mammals and plants (294). The chemical identity of patulin (348) was proposed initially incorrectly in 1948 (295), with the structure corrected by Woodward and Singh the following year to the structure shown (348, Fig. 7.1). 

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