Coumaroyl-coenzyme A is the
thioester
In organic chemistry, thioesters are organosulfur compounds with the functional group . They are analogous to carboxylate esters () with the sulfur in the thioester playing the role of the linking oxygen in the carboxylate ester, as implied by t ...
of
coenzyme-A and
coumaric acid Coumaric acid is a phenolic derivative of cinnamic acid having a hydroxy group
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In ...
. Coumaroyl-coenzyme A is a central intermediate in the biosynthesis of myriad natural products found in plants. These products include
lignols (precursors to
lignin
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity ...
and
lignocellulose
Lignocellulose refers to plant dry matter (biomass), so called lignocellulosic biomass. It is the most abundantly available raw material on the Earth for the production of biofuels. It is composed of two kinds of carbohydrate polymers, cellulose a ...
),
flavonoids
Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans.
Chemically, flavonoids ...
,
isoflavonoids
Isoflavonoids are a class of flavonoid phenolic compounds, many of which are biologically active. Isoflavonoids and their derivatives are sometimes referred to as phytoestrogens, as many isoflavonoid compounds have biological effects via the estro ...
,
coumarin
Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by a lactone-like chain , forming a second six-membered h ...
s,
aurones
An aurone is a heterocyclic chemical compound which is a type of flavonoid. There are two isomers of the molecule, with (''E'')- and (''Z'')-configurations. The molecule contains a benzofuran element associated with a benzylidene linked in posi ...
,
stilbenes
Stilbenoids are hydroxylated derivatives of stilbene. They have a C6–C2–C6 structure. In biochemical terms, they belong to the family of phenylpropanoids and share most of their biosynthesis pathway with chalcones. Most stilbenoids are pro ...
,
catechin
Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids.
The name of the catechin chemical family derives from ''catechu'', which is the tannic ...
, and other
phenylpropanoid
The phenylpropanoids are a diverse family of organic compounds that are synthesized by plants from the amino acids phenylalanine and tyrosine. Their name is derived from the six-carbon, aromatic phenyl group and the three-carbon propene tail of ...
s.
Biosynthesis and significance
It is generated in nature from
phenylalanine
Phenylalanine (symbol Phe or F) is an essential α-amino acid with the formula . It can be viewed as a benzyl group substituted for the methyl group of alanine, or a phenyl group in place of a terminal hydrogen of alanine. This essential amino a ...
, which is converted by
PAL
Phase Alternating Line (PAL) is a colour encoding system for analogue television. It was one of three major analogue colour television standards, the others being NTSC and SECAM. In most countries it was broadcast at 625 lines, 50 fields (25 ...
to trans-
cinnamate
Cinnamic acid is an organic compound with the formula C6H5-CH=CH- COOH. It is a white crystalline compound that is slightly soluble in water, and freely soluble in many organic solvents. Classified as an unsaturated carboxylic acid, it occurs na ...
. Trans-cinnamate is hydroxylated by
trans-cinnamate 4-monooxygenase
In enzymology, a trans-cinnamate 4-monooxygenase () is an enzyme that catalyzes the chemical reaction
:trans-cinnamate + NADPH + H+ + O2 \rightleftharpoons 4-hydroxycinnamate + NADP+ + H2O
The 4 substrates of this enzyme are trans-cinnamate, ...
to give 4-hydroxycinnamate (i.e, coumarate). Coumarate is condensed with coenzyme-A in the presence of
4-coumarate-CoA ligase:
:ATP + 4-coumarate + CoA
AMP + diphosphate + 4-coumaroyl-CoA.
Enzymes using Coumaroyl-Coenzyme A
*
Anthocyanin 3-O-glucoside 6''-O-hydroxycinnamoyltransferase
Anthocyanin 3-O-glucoside 6″-O-hydroxycinnamoyltransferase is an enzyme forming delphinidin 3-(6-''p''-coumaroyl)glucoside from delphinidin 3-''O''-glucoside (myrtillin) and ''p''-coumaroyl-CoA.
It is an enzyme in the anthocyanin biosynthesi ...
*
Anthocyanin 5-aromatic acyltransferase
*
Chalcone synthase
Chalcone synthase or naringenin-chalcone synthase (CHS) is an enzyme ubiquitous to higher plants and belongs to a family of polyketide synthase enzymes (PKS) known as type III PKS. Type III PKSs are associated with the production of chalcones, a ...
*
4-Coumarate-CoA ligase
*
6'-Deoxychalcone synthase
*
Agmatine N4-coumaroyltransferase
*
Flavonol-3-O-triglucoside O-coumaroyltransferase
*
Naringenin-chalcone synthase
Chalcone synthase or naringenin-chalcone synthase (CHS) is an enzyme ubiquitous to higher plants and belongs to a family of polyketide synthase enzymes (PKS) known as type III PKS. Type III PKSs are associated with the production of chalcones, a ...
*
Shikimate O-hydroxycinnamoyltransferase
*
Trihydroxystilbene synthase
In enzymology, a trihydroxystilbene synthase () is an enzyme that catalyzes the chemical reaction
:3 malonyl-CoA + 4-coumaroyl-CoA \rightleftharpoons 4 CoA + 3,4',5-trihydroxy-stilbene + 4 CO2
Thus, the two substrates of this enzyme are malonyl ...
References
Thioesters of coenzyme A
Hydroxycinnamic acid esters
Vinylogous carboxylic acids
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