Definition
ChEBI: L-canavanine is a non-proteinogenic L-alpha-amino acid that is L-homoserine substituted at oxygen with a guanidino (carbamimidamido) group. Although structurally related to L-arginine, it is non-proteinogenic. It has a role as a phytogenic insecticide and a plant metabolite. It is functionally related to a L-homoserine. It is a conjugate base of a L-canavanine(1+). It is a tautomer of a L-canavanine zwitterion.
Biochem/physiol Actions
L-Canavanine is a naturally occurring L-amino acid that interferes with L-arginine-utilizing enzymes due to its structural similarity. It is a selective inhibitor of inducible nitric oxide synthase (iNOS). Overproduction of NO by iNOS plays a crucial role in the pathophysiology of septic shock and chronic inflammation.
Purification Methods
Crystallise S-canavanine from absolute EtOH or aqueous EtOH. [Tomiyama J Biol Chem 111 48 1935 gave pK9.25 (COOH), pK 7.4 (guanidinium), pK 11.5 (NH4+), Gulland & Morris J Chem Soc 763 1935,(±) Frankel et al. J Chem Soc 3127 1963, Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 pp 2622-2628 1961, Beilstein 4 III 1636, 4 IV 3188.]
