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MetaCyc Pathway: C-glycosylflavone biosynthesis I
Inferred from experiment

Enzyme View:

Pathway diagram: C-glycosylflavone biosynthesis I

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: BiosynthesisSecondary Metabolites BiosynthesisPhenylpropanoid Derivatives BiosynthesisFlavonoids BiosynthesisFlavanones Biosynthesis

Some taxa known to possess this pathway include : Fagopyrum esculentum, Oryza sativa

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]

Created 17-Sep-2010 by Pujar A, Boyce Thompson Institute
Revised 18-Jan-2013 by Foerster H, Boyce Thompson Institute


BrazierHicks09: Brazier-Hicks M, Evans KM, Gershater MC, Puschmann H, Steel PG, Edwards R (2009). "The C-glycosylation of flavonoids in cereals." J Biol Chem 284(27);17926-34. PMID: 19411659

Du10: Du Y, Chu H, Chu IK, Lo C (2010). "CYP93G2 is a flavanone 2-hydroxylase required for C-glycosylflavone biosynthesis in rice." Plant Physiol 154(1);324-33. PMID: 20647377

KARIN85: KARIN MARIA VALANT-VETSCHERA (1985). "C-Glycosylflavones as an Accumulation Tendency: A Critical Review." The Botanical Review, Vol 51, 1985, pg 1-52.

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.

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

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.

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Lazarowski03: Lazarowski ER, Shea DA, Boucher RC, Harden TK (2003). "Release of cellular UDP-glucose as a potential extracellular signaling molecule." Mol Pharmacol 63(5);1190-7. PMID: 12695547

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Fri Apr 29, 2016, biocyc11.