New NO-donors with antithrombotic and vasodilating activities, IV: Chemical reactivity of nitrosimines and its implications for their pharmacologic properties

Article abstract of DOI:10.1002/ardp.19943270603

Nitrososydnone-5-imines and Thiazole-2-nitrosimines are susceptible to photolytic cleavage of the =N-NO bond. This can be achieved with a tungsten lamp. In water the corresponding syndnone imine salts are formed in 90% yield at 37°C. Only at higher temp. (70°C) ring opening is observed. In methanol about 25% of sydnones are obtained. On the other hand NO^. and N₂O were detected in the head space of the reaction vials when oxygen was excluded. The formation of N₂O from nitrososydnone imine was increased up to elevenfold by glutathione while the amount of NO^. was decreased. In the presence of light and thiols soluble guanylate cyclase (s-GC) was stimulated. The results suggest tnat the nitroxylate anion NO^- plays an important role in the stimulation of s-GC.