Enzymes, plant introduction cytochrome

Transgenic oil crops containing large amounts of DHA, EPA, and GLA offer new opportunities. Plant desaturases with an amino-terminal cytochrome bj domain have been selected. These are enzymes that can participate in the introduction of a double bond into an acyl chain between an existing double bond and the carbonyl terminal (Murphy, 1999). 

Plant flavanones 12 are enzymatically converted to five major subclasses of flavo-noids. Flavanones 12 are oxidized to flavones 14 by the action of either a soluble flavone synthase (FSl) or, as in most cases, a membrane-bound cytochrome P450 monooxygenase flavone synthase (FSII) [65]. Havone synthases belong to the oxidoreductase family of enzymes and effectively remove the stereocenter from flavanones 12 by oxidation of C3 and introduction of a double bond between C2 and C3. Apigenin, luteolin, and chrysin are common flavones 14 that contribute to human diet as glycosides and are found in large quantities in parsley and celery [66-68]. 

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