Isochorismic acid

Isochorismic acid
Names
	IUPAC name (5S,6S)-5-(1-carboxylatoethenoxy)-6-hydroxycyclohexa-1,3-diene-1-carboxylate
Identifiers
CAS Number	22642-82-6 ;
3D model (JSmol)	Interactive image; isochorismate(2-): Interactive image;
Beilstein Reference	8334070 ; isochorismate(2-): 2943868
ChEBI	CHEBI:17582; isochorismate(2-): CHEBI:29780;
ChemSpider	164276; isochorismate(2-): 26329824;
DrugBank	DB02793;
KEGG	C00885;
PubChem CID	5460580; isochorismate(2-): 5460580;
CompTox Dashboard (EPA)	DTXSID20945303;
	InChI InChI=1S/C10H10O6/c1-5(9(12)13)16-7-4-2-3-6(8(7)11)10(14)15/h2-4,7-8,11H,1H2,(H,12,13)(H,14,15)/t7-,8-/m0/s1 Key: NTGWPRCCOQCMGE-YUMQZZPRSA-N;
	SMILES O=C(O)C(OC1C=CC=C(C(=O)O)C1O)=C; isochorismate(2-): C=C(C(=O)[O-])O[C@H]1C=CC=C([C@@H]1O)C(=O)[O-];
Properties
Chemical formula	C10H10O6
Molar mass	226.184 g·mol−1
Density	1.49 g/cm³
Hazards
Flash point	297.4 °C
Related compounds
Related compounds	isoprephenate, chorismate
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Isochorismic acid, also called isochorismate, is an organic dibasic acid synthesized from chorismate.^[1]

Synthesis

The enzyme chorismate hydroxymutase (isochorismate synthase, CF 5.4.4.2) reversibly isomerizes chorismate into isochorismate, giving rise to one of the branches of the shikimate pathway.^[2]^[3] Isochorismate is a precursor in the biosynthesis of many natural compounds. Salicylic acid and terpenoid naphthoquinones (menaquinones, phylloquinones) are synthesized from isochorismate, although in some organisms these compounds can be synthesized from chorismate in alternative ways, not through isochorismate (for example, the futalosine pathway of menaquinone biosynthesis in some prokaryotes).^[4]^[5]^[6]

Discovery

The compound was discovered by Australian researchers in 1968 as an intermediate in the biosynthesis of 2,3-dihydroxybenzoate (ortho-pyrocatechate, an enterobactin precursor) from chorismate in Aerobacter aerogenes. The reaction presumably proceeds via nucleophilic attack of water at the C₂ carbon atom.^[7] The trivial name "isochorismic acid", which has been fixed for the compound, was proposed by these researchers, who described the substance for the first time.^[8]

Properties

Isochorismic acid is a thermodynamically unstable compound. In an aqueous solution at room temperature and pH = 7, isochorismate decomposes into a mixture of salicylate and meta-carboxyphenylpyruvate.^[9]^[8] The latter is formed from isoprephenate (also a thermodynamically unstable compound), which arises as a result of the [3,3]-sigmatropic rearrangement of isochorismate.

References

^ Wildermuth, Mary C.; Dewdney, Julia; Wu, Gang; Ausubel, Frederick M. (November 2001). "Isochorismate synthase is required to synthesize salicylic acid for plant defence". Nature. 414 (6863): 562–565. Bibcode:2001Natur.414..562W. doi:10.1038/35107108. ISSN 1476-4687. PMID 11734859. Retrieved 13 June 2025.
^ Dewick, Paul M. (3 January 2002). Medicinal Natural Products: A Biosynthetic Approach. John Wiley & Sons. p. 124. ISBN 978-0-471-49641-0. Retrieved 13 June 2025.
^ Conn, Eric E. (8 March 2013). The Shikimic Acid Pathway. Springer Science & Business Media. p. 18. ISBN 978-1-4684-8056-6. Retrieved 13 June 2025.
^ Hooykaas, P. J. J.; Hall, M. A.; Libbenga, K. R. (13 May 1999). Biochemistry and Molecular Biology of Plant Hormones. Elsevier. p. 305. ISBN 978-0-08-086094-7.
^ Luckner, M. (11 December 2013). Secondary Metabolism in Microorganisms, Plants and Animals. Springer Science & Business Media. p. 264. ISBN 978-3-662-02384-6. Retrieved 13 June 2025.
^ Arakawa, Chisato; Kuratsu, Masahiro; Furihata, Kazuo; Hiratsuka, Tomoshige; Itoh, Nobuya; Seto, Haruo; Dairi, Tohru (20 January 2011). "Diversity of the Early Step of the Futalosine Pathway". Antimicrobial Agents and Chemotherapy. 55 (2): 913–916. doi:10.1128/aac.01362-10. Retrieved 13 June 2025.
^ He, Ze; Stigers Lavoie, Kimberly D.; Bartlett, Paul A.; Toney, Michael D. (3 March 2004). "Conservation of Mechanism in Three Chorismate-Utilizing Enzymes". Journal of the American Chemical Society. 126 (8): 2378–2385. Bibcode:2004JAChS.126.2378H. doi:10.1021/ja0389927. ISSN 0002-7863. PMID 14982443. Retrieved 13 June 2025.
^ ^a ^b Young, I. G.; Batterham, T. J.; Gibson, F. (6 May 1969). "The isolation, identification and properties of isochorismic acid. An intermediate in the biosynthesis of 2,3-dihydroxybenzoic acid". Biochimica et Biophysica Acta (BBA) - General Subjects. 177 (3): 389–400. doi:10.1016/0304-4165(69)90301-8. ISSN 0304-4165. PMID 5787238. Retrieved 13 June 2025.
^ Haslam, Edwin (20 May 2014). The Shikimate Pathway: Biosynthesis of Natural Products Series. Elsevier. p. 98. ISBN 978-1-4831-6118-1. Retrieved 13 June 2025.

[1] Wildermuth, Mary C.; Dewdney, Julia; Wu, Gang; Ausubel, Frederick M. (November 2001). "Isochorismate synthase is required to synthesize salicylic acid for plant defence". Nature. 414 (6863): 562–565. Bibcode:2001Natur.414..562W. doi:10.1038/35107108. ISSN 1476-4687. PMID 11734859. Retrieved 13 June 2025.

[2] Dewick, Paul M. (3 January 2002). Medicinal Natural Products: A Biosynthetic Approach. John Wiley & Sons. p. 124. ISBN 978-0-471-49641-0. Retrieved 13 June 2025.

[3] Conn, Eric E. (8 March 2013). The Shikimic Acid Pathway. Springer Science & Business Media. p. 18. ISBN 978-1-4684-8056-6. Retrieved 13 June 2025.

[4] Hooykaas, P. J. J.; Hall, M. A.; Libbenga, K. R. (13 May 1999). Biochemistry and Molecular Biology of Plant Hormones. Elsevier. p. 305. ISBN 978-0-08-086094-7.

[5] Luckner, M. (11 December 2013). Secondary Metabolism in Microorganisms, Plants and Animals. Springer Science & Business Media. p. 264. ISBN 978-3-662-02384-6. Retrieved 13 June 2025.

[6] Arakawa, Chisato; Kuratsu, Masahiro; Furihata, Kazuo; Hiratsuka, Tomoshige; Itoh, Nobuya; Seto, Haruo; Dairi, Tohru (20 January 2011). "Diversity of the Early Step of the Futalosine Pathway". Antimicrobial Agents and Chemotherapy. 55 (2): 913–916. doi:10.1128/aac.01362-10. Retrieved 13 June 2025.

[7] He, Ze; Stigers Lavoie, Kimberly D.; Bartlett, Paul A.; Toney, Michael D. (3 March 2004). "Conservation of Mechanism in Three Chorismate-Utilizing Enzymes". Journal of the American Chemical Society. 126 (8): 2378–2385. Bibcode:2004JAChS.126.2378H. doi:10.1021/ja0389927. ISSN 0002-7863. PMID 14982443. Retrieved 13 June 2025.

[Y-8] Young, I. G.; Batterham, T. J.; Gibson, F. (6 May 1969). "The isolation, identification and properties of isochorismic acid. An intermediate in the biosynthesis of 2,3-dihydroxybenzoic acid". Biochimica et Biophysica Acta (BBA) - General Subjects. 177 (3): 389–400. doi:10.1016/0304-4165(69)90301-8. ISSN 0304-4165. PMID 5787238. Retrieved 13 June 2025.

[9] Haslam, Edwin (20 May 2014). The Shikimate Pathway: Biosynthesis of Natural Products Series. Elsevier. p. 98. ISBN 978-1-4831-6118-1. Retrieved 13 June 2025.

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