Chorismic acid

Chorismic acid

Names
IUPAC name (3R,4R)-3-[(1-carboxyvinyl)oxy]-4-hydroxycyclohexa-1,5-diene-1-carboxylic acid
Identifiers
CAS Number	617-12-9
ChEBI	CHEBI:17333
ChemSpider	11542
Jmol interactive 3D	Image
InChI InChI=1S/C10H10O6/c1-5(9(12)13)16-8-4-6(10(14)15)2-3-7(8)11/h2-4,7-8,11H,1H2,(H,12,13)(H,14,15)/t7-,8-/m1/s1 Key: WTFXTQVDAKGDEY-HTQZYQBOSA-N InChI=1/C10H10O6/c1-5(9(12)13)16-8-4-6(10(14)15)2-3-7(8)11/h2-4,7-8,11H,1H2,(H,12,13)(H,14,15)/t7-,8-/m1/s1 Key: WTFXTQVDAKGDEY-HTQZYQBOBD
SMILES O=C(O)C1=C/[C@@H](O/C(C(=O)O)=C)[C@H](O)/C=C1
Properties
Chemical formula	C10H10O6
Molar mass	226.18 g·mol^−1
Melting point	140 °C (284 °F; 413 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Chorismic acid, more commonly known as its anionic form chorismate, is an important biochemical intermediate in plants and microorganisms. It is a precursor for:

• The aromatic amino acids phenylalanine, tryptophan, and tyrosine
• Indole, indole derivatives and tryptophan
• 2,3-Dihydroxybenzoic acid (DHB) used for enterobactin biosynthesis
• The plant hormone salicylic acid^[1]
• Many alkaloids and other aromatic metabolites.
• The folate precursor para-aminobenzoate (pABA)
• The biosynthesis of Vitamin K and folate in plants and microorganisms.

The name chorismic acid derives from a classical Greek word, χωρίζω meaning "to separate",^[2] because the compound plays a role as a branch-point in aromatic amino acid biosynthesis.^[3]

Biosynthesis

Shikimate → shikimate-3-phosphate → 5-enolpyruvylshikimate-3-phosphate (5-O-(1-carboxyvinyl)-3-phosphoshikimate)

Chorismate synthase is an enzyme that catalyzes the final chemical reaction 5-O-(1-carboxyvinyl)-3-phosphoshikimate → chorismate + phosphate.

Metabolism

Chorismate is transformed into para-aminobenzoic acid by the enzymes 4-amino-4-deoxychorismate synthase and 4-amino-4-deoxychorismate lyase.

Chorismate lyase is an enzyme that transforms chorismate into 4-hydroxybenzoate and pyruvate. This enzyme catalyses the first step in ubiquinone biosynthesis in Escherichia coli and other Gram-negative bacteria.

External links

• Shikimate and chorismate biosynthesis

References

1. Wildermuth MC, Dewdney J, Wu G, Ausubel FM (2001). "Isochorismate synthase is required to synthesize salicylic acid for plant defence". Nature 414 (6863): 562–5. doi:10.1038/35107108. PMID 11734859.
2. Henry George Liddell, Robert Scott, Henry Stuart Jones and Roderick McKenzie. A Greek-English Lexicon. ISBN 0-19-864226-1.
3. Gibson, F. (1999). "The elusive branch-point compound of aromatic amino acid biosynthesis". Trends in Biochemical Sciences 24 (1): 36–38. doi:10.1016/S0968-0004(98)01330-9. PMID 10087921.