Search results
Results From The WOW.Com Content Network
Flavonoids are synthesized by the phenylpropanoid metabolic pathway in which the amino acid phenylalanine is used to produce 4-coumaroyl-CoA. [1] This can be combined with malonyl-CoA to yield the true backbone of flavonoids, a group of compounds called chalcones , which contain two phenyl rings.
Flavonoids are widely distributed in plants, fulfilling many functions. [1] They are the most important plant pigments for flower coloration, producing yellow or red/blue pigmentation in petals designed to attract pollinator animals. In higher plants, they are involved in UV filtration, symbiotic nitrogen fixation, and floral pigmentation.
Type III PKSs are associated with the production of chalcones, a class of organic compounds found mainly in plants as natural defense mechanisms and as synthetic intermediates. CHS was the first type III PKS to be discovered. [1] It is the first committed enzyme in flavonoid biosynthesis. [2]
In plants, all phenylpropanoids are derived from the amino acids phenylalanine and tyrosine. Phenylalanine ammonia-lyase (PAL, a.k.a. phenylalanine/tyrosine ammonia-lyase) is an enzyme that transforms L-phenylalanine and tyrosine into trans-cinnamic acid and p-coumaric acid, respectively.
4-Coumaroyl-CoA is the central biosynthetic precursor to phenylpropanoids (shown in protonated state) Phenylalanine Tyrosine. The phenylpropanoids are a diverse family of organic compounds that are biosynthesized by plants from the amino acids phenylalanine and tyrosine in the shikimic acid pathway. [1]
Phenolics are formed by three different biosynthetic pathways: (i) the shikimate/chorizmate or succinylbenzoate pathway, which produces the phenyl propanoid derivatives (C6–C3); (ii) the acetate/malonate or polyketide pathway, which produces the side-chain-elongated phenyl propanoids, including the large group of flavonoids (C6–C3–C6) and ...
The flavonoids are products from a cinnamoyl-CoA starter unit, with chain extension using three molecules of malonyl-CoA. Reactions are catalyzed by a type III PKS enzyme. These enzyme do not use ACPSs, but instead employ coenzyme A esters and have a single active site to perform the necessary series of reactions, e.g. chain extension ...
Chalcones are aromatic ketones with two phenyl rings that are also intermediates in the synthesis of many biological compounds. The closure of hydroxy chalcones causes the formation of the flavonoid structure. [3] Flavonoids are substances in the plant's secondary metabolism with an array of biological activities.