Issue 12, 1985

The mechanism of the nitrosation of α-amino acids: evidence for an intramolecular pathway

Abstract

The results of a kinetic study of the nitrosation of sarcosine, proline, cysteine, and the ethyl ester of sarcosine are reported. Under the conditions in which sarcosine and proline were studied, both first- and second-order terms were found for nitrite dependence. The experimental results are interpreted by a mechanism which involves NO+ and N2O3 as direct nitrosating agents, while the effect of acidity changes on the first-order term for nitrite shows that the N-nitroso compound is also formed in a parallel reaction in which a slow intramolecular rearrangement follows the attack of NO+ on the carboxylate group of the amino acid. This pathway is confirmed by the absence of such a parallel reaction in the nitrosation of the ethyl ester of sarcosine. The influence of acidity on the nitrosation of cysteine shows that S-nitrosation is brought about by the reaction of NO+ with both the N-protonated, HSCH2–CH(NH3)–CO2H, and zwitterion, HSCH2–CH([graphic omitted]H3)–CO2, forms of the amino acid. The values obtained for the bimolecular rate constants are compatible with diffusion control, the difference between the values for both forms of the amino acid being explicable in terms of charges of the reagents.

Article information

Article type
Paper

J. Chem. Soc., Perkin Trans. 2, 1985, 1859-1864

The mechanism of the nitrosation of α-amino acids: evidence for an intramolecular pathway

J. Casado, A. Castro, J. R. Leis, M. Mosquera and M. E. Peña, J. Chem. Soc., Perkin Trans. 2, 1985, 1859 DOI: 10.1039/P29850001859

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements