Fungi importance

Table 17.1 Specific mycotoxins that are produced by different genera of fungi important for food safety...

Other materials based on EDA have also been suggested as fungicides. The most important of the imida2oline type (162) is 2-heptadecyl-2-imida2oline (163), prepared from EDA and stearic acid [57-11-4]. It is used as the acetate salt for control of apple scab and cherry leaf spot. A 2 1 EDA—copper sulfate complex has been suggested for control of aquatic fungi (164). 

It grew out of another discovery in the senior author s laboratory, namely, that Reichstein s compound S could be converted in high yield into 11-epicortisol (1) by the enzymes of fungi of the genus Aspergillus The conversion of this inactive substance into the hormone cortisol thus became a problem of considerable importance. A route involving the 9,11-dehydro steroid (3) readily prepared from 11-epicortisol via its 21-acetate 11-tosylate... 

Aldol reactions occur in many biological pathways, but are particularly important in carbohydrate metabolism, where enzymes called aldolases catalyze the addition of a ketone enolate ion to an aldehvde. Aldolases occur in all organisms and are of two types. Type 1 aldolases occur primarily in animals and higher plants type II aldolases occur primarily in fungi and bacteria. Both types catalyze the same kind of reaction, but type 1 aldolases operate place through an enamine, while type II aldolases require a metal ion (usually 7n2+) as Lewis acid and operate through an enolate ion. 

Medicinal chemistry has frequently drawn inspiration and important new leads from the examination of natural products, and this was proven to be the case once more. In 1992, researchers at Merck and Glaxo announced, almost simultaneously, the independent discovery of the same new class of natural products from two different fungi. As a consequence, the same family of natural products has two names - the zaragozic acids (Merck)4 or the squalestatins (Glaxo).5 A typical member of the family, zaragozic acid A (squa-lestatin SI) (1) was shown to have a tremendous affinity for squalene synthase (K, = 79 pM for rat microsomal squalene synthase) and could even lower serum cholesterol levels in vivo in a population of marmosets.6... 

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