Citrulline

Citrulline
Names
	IUPAC name 2-Amino-5-(carbamoylamino)pentanoic acid
Identifiers
CAS Number	627-77-0 ; 13594-51-9 (D) ; 372-75-8 (L) ;
3D model (JSmol)	Interactive image;
3DMet	B01217;
Beilstein Reference	1725417, 1725415 D, 1725416 L
ChEBI	CHEBI:18211 ;
ChEMBL	ChEMBL444814 ;
ChemSpider	810 ; 553200 D ; 9367 L ;
DrugBank	DB00155 ;
ECHA InfoCard	100.006.145
EC Number	211-012-2;
Gmelin Reference	774677 L
IUPHAR/BPS	722;
KEGG	D07706 ;
MeSH	Citrulline
PubChem CID	833; 637599 D; 9750 L;
UNII	1OYO2NV4NM ; KNS2VUH6P2 (D) ; 29VT07BGDA (L) ;
CompTox Dashboard (EPA)	DTXSID80883373 ;
	InChI InChI=1S/C6H13N3O3/c7-4(5(10)11)2-1-3-9-6(8)12/h4H,1-3,7H2,(H,10,11)(H3,8,9,12) Key: RHGKLRLOHDJJDR-UHFFFAOYSA-N ;
	SMILES NC(CCCNC(N)=O)C(O)=O;
Properties
Chemical formula	C6H13N3O3
Molar mass	175.188 g·mol−1
Appearance	White crystals
Odor	Odourless
log P	−1.373
Acidity (pKa)	2.508
Basicity (pKb)	11.489
Thermochemistry
Heat capacity (C)	232.80 J K−1 mol−1
Std molar; entropy (S⦵298)	254.4 J K−1 mol−1
Related compounds
Related alkanoic acids	N-Acetylaspartic acid; Aceglutamide; N-Acetylglutamic acid; Pivagabine;
Related compounds	Bromisoval; Carbromal;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

The organic compound citrulline is an α-amino acid.^[2] Its name is derived from citrullus, the Latin word for watermelon. Although named and described by gastroenterologists since the late 19th century, it was first isolated from watermelon in 1914 by Japanese researchers Yatarō Koga (古賀彌太郎) and Ryō Ōtake (大嶽了)^[3]^[4] and further codified by Mitsunori Wada of Tokyo Imperial University in 1930.^[5]^[6]^[7] It has the formula H₂NC(O)NH(CH₂)₃CH(NH₂)CO₂H. It is a key intermediate in the urea cycle, the pathway by which mammals excrete ammonia by converting it into urea. Citrulline is also produced as a byproduct of the enzymatic production of nitric oxide from the amino acid arginine, catalyzed by nitric oxide synthase.^[8]

^ "Citrulline - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification. Retrieved 1 May 2012.
^ Banerjee, Aryamitra (2014-01-01), Gupta, Ramesh C. (ed.), "Chapter 15 - Gastrointestinal toxicity biomarkers", Biomarkers in Toxicology, Boston: Academic Press, pp. 269–277, doi:10.1016/b978-0-12-404630-6.00015-4, ISBN 978-0-12-404630-6, S2CID 88798984, retrieved 2020-11-10
^ Koga, Yatarō; Ōtake, Ryō (1914). "Study report on the constituents of squeezed watermelon". Tokyo Kagaku Kaishi [Journal of the Tokyo Chemical Society]. 35 (5): 519–528. doi:10.1246/nikkashi1880.35.519.
^ Fragkos, Konstantinos C.; Forbes, Alastair (2011). "Was citrulline first a laxative substance? The truth about modern citrulline and its isolation" (PDF). Nihon Ishigaku Zasshi [Journal of the Japanese Society for the History of Medicine]. 57 (3): 275–292. PMID 22397107.
^ Wada, Mitsunori (1930). "On the occurrence of a new amino acid in watermelon. Citrullus vulgaris, Schrad". Proceedings of the Imperial Academy. 6 (1): 15–17. doi:10.2183/pjab1912.6.15.
^ Wada, Mitsunori (1930). "On the occurrence of a new amino acid in watermelon, Citrullus vulgaris, Schrad". Bulletin of the Agricultural Chemical Society of Japan. 6 (1–5): 32–34. doi:10.1271/bbb1924.6.32.
^ Wada, Mitsunori (1930). "Über Citrullin, eine neue Aminosäure im Preßsaft der Wassermelone, Citrullus vulgaris, Schrad". Biochemische Zeitschrift (in German). 224: 420–429.
^ "Nos2 - Nitric Oxide Synthase". Uniprot.org. Uniprot Consortium. Retrieved 10 February 2015.

[1] "Citrulline - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 16 September 2004. Identification. Retrieved 1 May 2012.

[:0-2] Banerjee, Aryamitra (2014-01-01), Gupta, Ramesh C. (ed.), "Chapter 15 - Gastrointestinal toxicity biomarkers", Biomarkers in Toxicology, Boston: Academic Press, pp. 269–277, doi:10.1016/b978-0-12-404630-6.00015-4, ISBN 978-0-12-404630-6, S2CID 88798984, retrieved 2020-11-10

[Koga1914-3] Koga, Yatarō; Ōtake, Ryō (1914). "Study report on the constituents of squeezed watermelon". Tokyo Kagaku Kaishi [Journal of the Tokyo Chemical Society]. 35 (5): 519–528. doi:10.1246/nikkashi1880.35.519.

[Fragkos2011-4] Fragkos, Konstantinos C.; Forbes, Alastair (2011). "Was citrulline first a laxative substance? The truth about modern citrulline and its isolation" (PDF). Nihon Ishigaku Zasshi [Journal of the Japanese Society for the History of Medicine]. 57 (3): 275–292. PMID 22397107.

[Wada1930a-5] Wada, Mitsunori (1930). "On the occurrence of a new amino acid in watermelon. Citrullus vulgaris, Schrad". Proceedings of the Imperial Academy. 6 (1): 15–17. doi:10.2183/pjab1912.6.15.

[Wada1930b-6] Wada, Mitsunori (1930). "On the occurrence of a new amino acid in watermelon, Citrullus vulgaris, Schrad". Bulletin of the Agricultural Chemical Society of Japan. 6 (1–5): 32–34. doi:10.1271/bbb1924.6.32.

[Wada1930c-7] Wada, Mitsunori (1930). "Über Citrullin, eine neue Aminosäure im Preßsaft der Wassermelone, Citrullus vulgaris, Schrad". Biochemische Zeitschrift (in German). 224: 420–429.

[8] "Nos2 - Nitric Oxide Synthase". Uniprot.org. Uniprot Consortium. Retrieved 10 February 2015.

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