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.
|Superclasses:||Biosynthesis → Secondary Metabolites Biosynthesis → Phenylpropanoid Derivatives Biosynthesis → Flavonoids Biosynthesis → Aurones Biosynthesis|
Some taxa known to possess this pathway include : Medicago truncatula
Expected Taxonomic Range: Fabaceae
Aurones are a subclass of flavonoids derived from the phenylpropanoid biosynthesis pathway. In legumes the chalcone synthase forms 6-deoxy isoliquiritigenin as a diverging set of secondary metabolites. The molecule isoliquiritigenin is metabolized to liquiritigen via chalcone isomerase, a precursor molecule to a range of 5 deoxy flavone, flavonols and isoflavone. However, the route for aurone biosynthesis deviates from these other products as they are directly synthesized from isoliquiritigenin [Farag09]. Aurones are implicated in flower pigmentation [Nakayama00], [Nakayama01], and in defense responses. For humans they are important as anticancer, anti diabetic and antibacterial agents.
hispidol was isolated from Soya hispida along with isoflavone and isoflavone glucosides [Frakas68]. hispidol and its glucosides are elicited in response to yeast elicitor or methyl jasmonate (MeJa) treatments. Their role in plant defense and as antifungal agents has been demonstrated. hispidol has been hypothesized as being formed as a result of spillover of precursor molecule isoliquiritigenin from the phenylpropanoid biosynthesis, thus balancing the upstream and downstream activities of the phenylpropanoid biosynthesis [Farag09]. The peroxidase enzymes are implicated as the catalyzing agents for hispidol. However, the presence and accumulation of these enzymes in the roots where hispidol does not accumulate may indicate that the formation of hispidol may be only one of the functions of these enzymes [Farag09].
Farag09: Farag MA, Deavours BE, de Fatima A, Naoumkina M, Dixon RA, Sumner LW (2009). "Integrated metabolite and transcript profiling identify a biosynthetic mechanism for hispidol in Medicago truncatula cell cultures." Plant Physiol 151(3);1096-113. PMID: 19571306
Nakayama00: Nakayama T, Yonekura-Sakakibara K, Sato T, Kikuchi S, Fukui Y, Fukuchi-Mizutani M, Ueda T, Nakao M, Tanaka Y, Kusumi T, Nishino T (2000). "Aureusidin synthase: a polyphenol oxidase homolog responsible for flower coloration." Science 290(5494);1163-6. PMID: 11073455
Nakayama01: Nakayama T, Sato T, Fukui Y, Yonekura-Sakakibara K, Hayashi H, Tanaka Y, Kusumi T, Nishino T (2001). "Specificity analysis and mechanism of aurone synthesis catalyzed by aureusidin synthase, a polyphenol oxidase homolog responsible for flower coloration." FEBS Lett 499(1-2);107-11. PMID: 11418122
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