Inhibition of myrosinase

Enzymes of Aldehyde Production. Lipoxygenases are discussed elsewhere in this volume. The aldehyde-lyase has only recently been obtained even in crude extracts 145), However, use of 13- and 9-hydroper-oxyoctadecanoic acids to form Cg and C9 aldehydes and corresponding w-oxoacids is evidence that the pathway is correct (145). As with alliinase and myrosinase these reactions occur only when leaves or fruit are cut or crushed (138,143,144,145). If they are heated before blending or blended under N2 (138), little carbonyl compound is formed (142). H2O2 inhibits (138) this reaction as expected for lipoxygenase (153). lrarw-2-Hexenal is formed nonenzymatically from m-S-hexenal (138). 

In contrast to aliphatic glucosinolates, indolyl glucosinolates such as glucobrassidan and its myrosinase-catalyzed transformation products have been shown to inhibit chemical and other types of cardnogensis induced by polycyclic aromatic hydrocarbons and other iiutiators (17). Indolyl glucosinolates are found abundantly in crudferae vegetables and are present in relativdy large amounts in the canola varieties of rapeseed. 

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