Prephenic acid

Prephenic acid

Names
Preferred IUPAC name (1s,4s)-1-(2-Carboxy-2-oxoethyl)-4-hydroxycyclohexa-2,5-diene-1-carboxylic acid
Other names Prephenate; cis-1-Carboxy-4-hydroxy-α-oxo-2,5-cyclohexadiene-1-propanoic acid
Identifiers
CAS Number	126-49-8 (unspecified) Y 87664-40-2 (cis) Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:84387  N
ChemSpider	16735981  Y
MeSH	Prephenic+acid
PubChem CID	1028  (unspecified)
UNII	Z66B98Z97I  (unspecified) Y
CompTox Dashboard (EPA)	DTXSID60894109
InChI InChI=1S/C10H10O6/c11-6-1-3-10(4-2-6,9(15)16)5-7(12)8(13)14/h1-4,6,11H,5H2,(H,13,14)(H,15,16)/t6-,10+ Y Key: FPWMCUPFBRFMLH-XGAOUMNUSA-N Y InChI=1/C10H10O6/c11-6-1-3-10(4-2-6,9(15)16)5-7(12)8(13)14/h1-4,6,11H,5H2,(H,13,14)(H,15,16)/t6-,10+ Key: FPWMCUPFBRFMLH-XGAOUMNUBN
SMILES O=C(O)[C@@]/1(CC(=O)C(O)=O)\C=C/[C@@H](O)\C=C\1
Properties
Chemical formula	C10H10O6
Molar mass	226.184 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N  verify  (what is  YN ?) Infobox references

Prephenic acid, commonly also known by its anionic form prephenate, is an intermediate in the biosynthesis of the aromatic amino acids phenylalanine and tyrosine, as well as of a large number of secondary metabolites of the shikimate pathway.

Occurrence and biological significance

Prephenic acid occurs naturally as an intermediate in the biosynthesis of phenylalanine and tyrosine via the shikimic acid pathway. ^{[1] [2]} It is formed from chorismic acid by chorismate mutase: ^[3]

The biosynthesis involves a [3,3]-sigmatropic Claisen rearrangement of chorismic acid. ^{[4] [5]}

Prephenic acid can be dehydrated by prephenate dehydratase to phenylpyruvic acid, which is a precursor of phenylalanine. ^{[6] [7]}

prephenic acid

 

 

CO₂ + H₂O

 

CO₂ + H₂O

 

phenylpyruvic acid

Alternatively, it can be decarboxylated and oxidised by prephenate dehydrogenase to give 4-hydroxyphenylpyruvic acid, which is a precursor of tyrosine: ^{[1] [8]}

prephenic acid

+ NADP⁺

 

 

 

CO₂ + H⁺

 

CO₂ + H⁺

 

4-hydroxyphenylpyruvic acid

+ NADPH

 

Synthesis

Prephenic acid is unstable; as a 1,4-cyclohexadiene, it is easily aromatized, for example, under the influence of acids or bases. This instability makes both isolation and synthesis difficult. Prephenic acid was first isolated from mutants of Escherichia coli that were unable to convert prephenic acid to phenylpyruvic acid. During this process, the barium salt was obtained. ^[2]

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 ^[9] that of the two possible diastereoisomers, 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 (1s,4s) according to the new IUPAC stereochemistry rules (2013). ^[10]

The other stereoisomer, i.e. trans or, better, (1r,4r), is called epiprephenic.

See also

• C₁₀H₁₀O₆

References

1. Richard G.H. Cotton, Frank Gibson (April 1965), "The biosynthesis of phenylalanine and tyrosine; enzymes converting chorismic acid into prephenic acid and their relationships to prephenate dehydratase and prephenate dehydrogenase", Biochimica et Biophysica Acta (BBA) - General Subjects, vol. 100, no. 1, pp. 76–88, doi:10.1016/0304-4165(65)90429-0, PMID   14323651
2. H. Plieninger (July 1962), "Prephenic Acid: Properties and the Present Status of its Synthesis", Angewandte Chemie International Edition in English, vol. 1, no. 7, pp. 367–372, doi:10.1002/anie.196203671
3. Kast P, Grisostomi C, Chen IA, Li S, Krengel U, Xue Y, Hilvert D (November 2000). "A strategically positioned cation is crucial for efficient catalysis by chorismate mutase". The Journal of Biological Chemistry. 275 (47): 36832–8. doi: 10.1074/jbc.M006351200 . PMID   10960481.
4. Helmut Goerisch (1978). "On the mechanism of the chorismate mutase reaction". Biochemistry . 17 (18): 3700–3705. doi:10.1021/bi00611a004. PMID   100134.
5. Peter Kast, Yadu B. Tewari, Olaf Wiest, Donald Hilvert, Kendall N. Houk, and Robert N. Goldberg (1997). "Thermodynamics of the Conversion of Chorismate to Prephenate: Experimental Results and Theoretical Predictions". J. Phys. Chem. B. 101 (50): 10976–10982. doi:10.1021/jp972501l.
6. Enzyme 4.2.1.51 at KEGG Pathway Database.
7. Cotton RG, Gibson F (1965). "The biosynthesis of phenylalanine and tyrosine; enzymes converting chorismic acid into prephenic acid and their relationships to prephenate dehydratase and prephenate dehydrogenase". Biochim. Biophys. Acta. 100: 76–88. doi:10.1016/0304-4165(65)90429-0. PMID   14323651.
8. Gamborg OL, Keeley FW (1966). "Aromatic metabolism in plants. I. A study of the prephenate dehydrogenase from bean plants". Biochim. Biophys. Acta. 115 (1): 65–72. doi:10.1016/0304-4165(66)90049-3. PMID   4379953.
9. Danishefsky, Samuel; Hirama, Masahiro; Fritsch, Nancy; Clardy, Jon (1979-11-01). "Synthesis of disodium prephenate and disodium epiprephenate. Stereochemistry of prephenic acid and an observation on the base-catalyzed rearrangement of prephenic acid to p-hydroxyphenyllactic acid". Journal of the American Chemical Society. 101 (23): 7013–7018. Bibcode:1979JAChS.101.7013D. doi:10.1021/ja00517a039. ISSN   0002-7863.
10. Favre, Henri A; Powell, Warren H (2013-12-17). Nomenclature of Organic Chemistry. doi:10.1039/9781849733069. ISBN   9780854041824.