S-Nitrosothiols: Materials, Reactivity and Mechanisms

Abstract

The article provides a comprehensive view of S-nitrosothiols, chemical behaviour, the pathways leading to their synthesis, their spectral properties, analytical methods of detection and determination, chemical and photochemical reactivity, kinetic aspects and suggested mechanisms. The structure parameters of S-nitrosothiols and the parent thiols are analysed with respect to their effect on the strengthening or weakening the S–NO bond, and in consequence on the S-nitrosothiol stability. This depends also on the ease of S–S bond formation in the product disulphide. These structural features seem to be crucial both to spontaneous as well as to Cu-catalysed decomposition. Principal emphasis is given here to the S-nitrosothiols’ ability to act as ligands and to the effect of coordination on the ligand properties. The chemical and photochemical behaviours of the complexes are described in more detail and their roles in chemical and biochemical systems are discussed. The aim of the article is to demonstrate that the contribution of S-nitrosothiols to chemical and biochemical processes is more diverse than supposed hitherto. Nevertheless, their role is predictable and, based on the correlation between structure and reactivity, many important mechanisms of biochemical processes can be interpreted and various applications designed.

Formation of S-Nitrosothiols from Regiospecific Reaction of Thiols with N-Nitrosotryptophan Derivatives

“…1, A-C). In this lipophilic environment the resonances of authentic 15 N-NANT and preformed 15 N-SNAP were found at 170 and 185 ppm (Fig. 1A) as well as at 455 ppm (Fig.…”

“…Synthesis of GS 15 NO-Glutathione (3.07 g) and Na 15 NO 2 (0.69 g) were allowed to react in a mixture of purified water (11 ml) and HCl (10 ml) for 40 min at 4°C. Afterward, 20 ml of acetone were added and stirred again for 10 min.…”

“…Next, the precipitate was washed with 10 ml of water, 3 ϫ 20 ml of acetone, and 3 ϫ 20 ml of ether, dried in an exsiccator, and stored at Ϫ20°C. The concentration of the prepared GS 15 NO was quantified by reading the optical density at max ϭ 545 nm (⑀ 545 ϭ 20 M Ϫ1 cm Ϫ1 ) (14).…”

“…Synthesis of 15 N-SNAP-NAP (5 g) was dissolved in a mixture of 500 ml of MeOH and 500 ml of HCl and cooled to 0°C. This mixture was stirred, and a nitrite solution (4.1 g Na 15 NO 2 /40 ml H 2 O) was slowly added dropwise.…”

“…The next day, the red-green crystals of 15 N-SNAP were filtered and dried in vacuo to yield ϳ90 -95% 15 N-SNAP (ϳ4.5 g). The concentration of 15 N-SNAP was spectrophotometrically analyzed at 595 nm in MeOH (⑀ 595 (MeOH) ϭ 16 M Ϫ1 cm Ϫ1 ) (15).…”