Citrulline

Title: Citrulline
CAS Registry Number: 372-75-8
CAS Name: N5-(Aminocarbonyl)-L-ornithine
Additional Names: d-ureidonorvaline; a-amino-d-ureidovaleric acid; Nd-carbamylornithine
Molecular Formula: C6H13N3O3
Molecular Weight: 175.19
Percent Composition: C 41.13%, H 7.48%, N 23.99%, O 27.40%
Line Formula: H2NCONH(CH2)3CH(NH2)COOH
Literature References: An amino acid, first isolated from the juice of watermelon, Citrullus vulgaris Schrad., Cucurbitaceae: Wada, Biochem. Z. 224, 420 (1930); isoln from casein: Wada, ibid. 257, 1 (1933). Synthesis from ornithine through copper complexes: Kurtz, J. Biol. Chem. 122, 477 (1938); by alkaline hydrolysis of arginine: Fox, ibid. 123, 687 (1938); from cyclopentanone oxime: Fox et al., J. Org. Chem. 6, 410 (1941). Crystallization: Matsuda et al., JP 71 174 (1971 to Ajinomoto), C.A. 74, 126056u (1971). Crystal and molecular structure: Naganathan, Venkatesan, Acta Crystallogr. 27B, 1079 (1971); Ashida et al., ibid. 28B, 1367 (1972). Use in asthenia and hepatic insufficiency: FR 2198739 (1974 to Hublot & Vallet), C.A. 82, 144952c (1975). Clinical trial in treatment of lysinuric protein intolerance: J. Rajantie et al., J. Pediatr. 97, 927 (1980); T. O. Carpenter et al., N. Engl. J. Med. 312, 290 (1985).
Properties: Prisms from methanol + water, mp 222°. [a]D20 +3.7° (c = 2). pK1 2.43; pK2 9.41. Sol in water. Insol in methanol, ethanol.
Melting point: mp 222°
pKa: pK1 2.43; pK2 9.41
Optical Rotation: [a]D20 +3.7° (c = 2)
Derivative Type: Hydrochloride
CAS Registry Number: 34312-10-2
Molecular Formula: C6H13N3O3.HCl
Molecular Weight: 211.65
Percent Composition: C 34.05%, H 6.67%, N 19.85%, O 22.68%, Cl 16.75%
Properties: Crystals, dec 185°. [a]D22 +17.9° (c = 2).
Optical Rotation: [a]D22 +17.9° (c = 2)
Derivative Type: Malate (salt)
CAS Registry Number: 54940-97-5
Trademarks: Stimol (Biocodex)
Molecular Formula: C6H13N3O3.C4H6O5
Molecular Weight: 309.27
Percent Composition: C 38.84%, H 6.19%, N 13.59%, O 41.39%
Therap-Cat: Treatment of asthenia.
Citrullol Citrus Red 2 Cizolirtine Clanobutin Clarase?

Citrulline
Skeletal formula of citrulline
Ball and stick model of zwitterionic citrulline
Identifiers
CAS number 627-77-0 N, 13594-51-9 R YesY, 372-75-8 S YesY
PubChem 833, 637599 R, 9750 S
ChemSpider 810 N, 553200 R YesY, 9367 S YesY
UNII 29VT07BGDA YesY
EC number 211-012-2
DrugBank DB00155
KEGG D07706 YesY
MeSH Citrulline
ChEBI CHEBI:18211 N
ChEMBL CHEMBL444814 YesY
IUPHAR ligand 722
Beilstein Reference 1725417, 1725415 R, 1725416 S
Gmelin Reference 774677 S
3DMet B01217
Jmol-3D images Image 1
Image 2
Properties
Molecular formula C6H13N3O3
Molar mass 175.19 g mol−1
Appearance White crystals
Odor Odourless
log P −1.373
Acidity (pKa) 2.508
Basicity (pKb) 11.489
Thermochemistry
Specific
heat capacity C
232.80 J K−1 mol−1
Std molar
entropy So298
254.4 J K−1 mol−1
Related compounds
Related alkanoic acids
  • N-Acetylaspartic acid
  • Aceglutamide
  • N-Acetylglutamic acid
  • Pivagabine
Related compounds
  • Bromisoval
  • Carbromal
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

The organic compound citrulline is an α-amino acid. Its name is derived from citrullus, the Latin word for watermelon, from which it was first isolated in 1914 by Koga & Odake. It was finally identified by Wada in 1930.[2] 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.