An aurone is a
heterocyclic
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...
chemical compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
which is a type of
flavonoid
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 ...
. There are two isomers of the molecule, with (''E'')- and (''Z'')-configurations. The molecule contains a
benzofuran
Benzofuran is the heterocyclic compound consisting of fused benzene and furan rings. This colourless liquid is a component of coal tar. Benzofuran is the "parent" of many related compounds with more complex structures. For example, psoralen i ...
element associated with a
benzylidene
Benzylidene compounds are, formally speaking, derivatives of benzylidene, although few are prepared from the carbene. Benzylidene acetal is a protecting group in synthetic organic chemistry of the form PhCH(OR)2. For example, 4,6-O-benzylidene- ...
linked in position 2. In aurone, a
chalcone
Chalcone is the organic compound C6H5C(O)CH=CHC6H5. It is an α,β-unsaturated ketone. A variety of important biological compounds are known collectively as chalcones or chalconoids.
Chemical properties
Chalcones have two absorption maxima a ...
-like group is closed into a 5-membered ring instead of the 6-membered ring more typical of
flavonoid
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 ...
s.
Aurone derivatives
Aurone forms the core for a family of derivatives which are known collectively as aurones. Aurones are plant flavonoids that provide
yellow color
Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In the R ...
to the flowers of some popular ornamental plants, such as
snapdragon
''Antirrhinum'' is a genus of plants commonly known as dragon flowers, snapdragons and dog flower because of the flowers' fancied resemblance to the face of a dragon that opens and closes its mouth when laterally squeezed. They are native to r ...
and
cosmos
The cosmos (, ) is another name for the Universe. Using the word ''cosmos'' implies viewing the universe as a complex and orderly system or entity.
The cosmos, and understandings of the reasons for its existence and significance, are studied in ...
.
Aurones including
4'-chloro-2-hydroxyaurone (C
15H
11O
3Cl) and
4'-chloroaurone (C
15H
9O
2Cl) can also be found in the
brown alga
Brown algae (singular: alga), comprising the class (biology), class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the ...
''
Spatoglossum variabile
''Spatoglossum'' is a marine brown algal genus in the family Dictyotaceae, with a worldwide distribution
For a description, see ''Spatoglossum'' Kützing, 1843.
Some accepted species
According to Algaebase:
*'' Spatoglossum asperum'' J.Agardh ...
''.
Most aurones are in a (''Z'')-configuration, which is the more stable configuration according to
Austin Model 1
Austin Model 1, or AM1, is a semi-empirical method for the quantum calculation of molecular electronic structure in computational chemistry. It is based on the Neglect of Differential Diatomic Overlap integral approximation. Specifically, it is a ...
computation,
but there are also some in the (''E'')-configurations such as
(E)-3'-O-β-d-glucopyranosyl-4,5,6,4'-tetrahydroxy-7,2'-dimethoxyaurone, found in ''
Gomphrena agrestis
''Gomphrena agrestis'' is a plant native to Cerrado vegetation in Brazil. This plant is cited in ''Flora Brasiliensis'' biosynthesized
Biosynthesis is a multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. In biosynthesis, simple compounds are modified, converted into other compounds, or joined to form macromolecules. ...
starting from
coumaryl-CoA.
Aureusidin synthase
Aureusidin synthase (, ''AmAS1'') is an enzyme with systematic name ''2',4,4',6'-tetrahydroxychalcone 4'-O-beta-D-glucoside:oxygen oxidoreductase''.
Aureusidin synthase has two main enzymatic tasks: hydroxylation at the 3-position on the B-ring ...
catalyzes the creation of aurones from chalcones through hydroxylation and oxidative cyclization.
Applications
Some aurone derivatives possess antifungal properties and analogy with flavonoids suggests that aurones could have other biological properties.
Related compound examples
*
Aureusidin
Aureusidin is an aurone, a type of flavonoid.
Metabolism
Aureusidin synthase
Aureusidin synthase (, ''AmAS1'') is an enzyme with systematic name ''2',4,4',6'-tetrahydroxychalcone 4'-O-beta-D-glucoside:oxygen oxidoreductase''.
Aureusidin synth ...
*
Hispidol (6,4'-dihydroxyaurone)
Hispidol on metabolomics.jp
/ref>
* Leptosidin
Leptosidin was the first aurone to be isolated in ''Coreopsis grandiflora
''Coreopsis grandiflora'' is a North American species of perennial plant in the family Asteraceae. The common name is large-flowered tickseed. It is found in eastern Can ...
* Sulfuretin (6,3',4'-trihydroxyaurone)
* 4,5,6-Trihydroxyaurone
References
{{aurone