This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
Synonyms: vitexin and isovitexin biosynthesis
|Superclasses:||Biosynthesis → Secondary Metabolites Biosynthesis → Phenylpropanoid Derivatives Biosynthesis → Flavonoids Biosynthesis → Flavanones Biosynthesis|
Expected Taxonomic Range: Viridiplantae
C-glycosylflavanones are widely present as secondary metabolites in plants. The sugars are attached directly to the flavonoid skeleton. This makes such flavonoids resistant to acid hydrolysis. The accumulation of C-glycosylflavones has been used by taxonomists in chemosystematics studies of certain families like Compositae [KARIN85]. C-glycosyl flavones have been isolated from a number of plant sources; flavoayamenin and luteoayamenin from petals of Iris nertshinskia, and swertisin and swertiajaponin [Ryosuke81]. In cereals, the C-glycosylflavones are involved in several important physiological functions including plant defense and are also valuable as nutritive components [Du10]. These phytocompounds have been shown to have several useful metabolic benefits as antioxidants, in cereals they are usually localized in the bran which is not consumed, therefore to metabolically engineer these useful compounds into the endosperm tissue (the consumed portion) it is necessary to know the biochemical machinery underlying the biosynthesis of these compounds [BrazierHicks09].
C-glycosylation is suggested to occur much earlier than O-glycosylation of flavonoid biosynthesis, in which the O-glycosylation occurs only at the terminal stages. In cereals the C-glycosylation is carried out in concert by the CGT and a dehydratase which act on the 2-hydroxyflavonones. This is an alternate route for the production of flavonoid metabolites [BrazierHicks09]
Ryosuke81: Ryosuke Hirose, Yukio Kazuta, Daiza Koga, Akio Ide, Kazuyoshi Yagishita (1981). "On the Structure of C-Glycosyl Flavones, Flavoayamenin and Luteoayamenin, in Petals of.Iris nertshinskia Loddiges form. albiflora Honda." Agric. Biol. Chem., 45(3), 551-55.
Kerscher87: Kerscher F, Franz G (1987). "Biosynthesis of vitexin and isovitexin: Enzymatic synthesis of the C-glycosylflavones vitexin and isovitexin with an enzyme preparation from Fagopyrum esculentum M. seedlings." Z Naturforsch 42c: 519-524.
Kerscher88: Kerscher F, Franz G (1988). "Isolation and Some Properties of an UDP-Glucose: 2-Hydroxyflavanone-6(or 8)-C-Glucosyltransferase from Fagopyrum esculentum M. Cotyledons." Journal of Plant Physiology 132:110-115.
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