Prephenic acid, commonly also known by its
anionic
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...
form prephenate, is an intermediate in the
biosynthesis of the aromatic
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha ...
s
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 ...
and
tyrosine
-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the Gr ...
, as well as of a large number of
secondary metabolites
Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the nor ...
of the
shikimate pathway.
It is biosynthesized by a
,3 sigmatropic Claisen rearrangement
The Claisen rearrangement is a powerful carbon–carbon bond-forming chemical reaction discovered by Rainer Ludwig Claisen. The heating of an allyl vinyl ether will initiate a ,3sigmatropic rearrangement to give a γ,δ-unsaturated carbonyl, ...
of
chorismate.
:
Stereochemistry
Prephenic acid is an example of achiral (optically inactive) molecule which has two
pseudoasymmetric atoms (''i.e.''
stereogenic but not
chirotopic centers), the C1 and the C4
cyclohexadiene ring atoms. It has been shown that of the two possible
diastereoisomers
In stereochemistry, diastereomers (sometimes called diastereoisomers) are a type of stereoisomer. Diastereomers are defined as non-mirror image, non-identical stereoisomers. Hence, they occur when two or more stereoisomers of a compound have dif ...
, the natural prephenic acid is one that has both substituents at higher priority (according to
CIP rules) on the two pseudoasymmetric carbons, ''i.e.'' the carboxyl and the hydroxyl groups, in the ''cis'' configuration, or (1''s'',4''s'') according to the new IUPAC stereochemistry rules (2013).
The other stereoisomer, ''i.e. trans'' or, better, (1''r'',4''r''), is called epiprephenic.
See also
*
C10H10O6
References
{{Reflist
Hydroxy acids
Alpha-keto acids
Dicarboxylic acids
Cyclohexadienes