2331. Citrulline

Nomenclature

CAS number: 372-75-8
N5-(Aminocarbonyl)-l-ornithine; δ-ureidonorvaline; α-amino-δ-ureidovaleric acid; Nδ-carbamylornithine.
C6H13N3O3; mol wt 175.19.
C 41.13%, H 7.48%, N 23.99%, O 27.40%.
H2NCONH(CH2)3CH(NH2)COOH.

Description and 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°. [α]D20 +3.7° (c = 2). pK1 2.43; pK2 9.41. Sol in water. Insol in methanol, ethanol.

Derivative

Hydrochloride.

Nomenclature

CAS number: 34312-10-2
C6H13N3O3.HCl; mol wt 211.65.
C 34.05%, H 6.67%, N 19.85%, O 22.68%, Cl 16.75%.

Properties

Crystals, dec 185°. [α]D22 +17.9° (c = 2).

Derivative

Malate (salt).

Nomenclature

CAS number: 54940-97-5
Stimol (Biocodex).
C6H13N3O3.C4H6O5; mol wt 309.27.
C 38.84%, H 6.19%, N 13.59%, O 41.39%.

Therapeutic Category

Treatment of asthenia.