NO Donors as Antiplatelet Agents

Inhibition of platelet activation by NO is not exclusively cGM P-dependent but involves mechanisms independent of cGM P like ribosylation or nitrosylation of proteins. For 

vasodilator stimulated phosphoprotein hsp27, heat shock protein hsp27 LASP, LIM and SH3 domain containing protein Tx, thromboxane IP3, inositol triphosphate ADP, adenosine 5 -diphosphate. Adapted from Refs. [44] and [116]. 

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Anhydro-5-amino-l,2,3,4-oxatriazolium hydroxides (6) act as NO donors. They stimulate guanyl cyclases selectively and some are potent antiplatelet, fibrinolytic, thrombolytic, or bronchiolytic agents <94MI 4l8-0l, 96BJP401). Some compounds exhibit antitumor activity <82USP4329355). 

Oxatriazolium-5-aminides (9) are structurally related to sydnon-imines (3). As with sydnonimines, the 5-imine derivatives are stable only as salts or in their N-acylated forms. 3-Cyclohexyl-1,2,3,4-oxatriazole-5-imine hydrochloride was first synthesized by Finnegan and Henry in 1965 [55]. The biological activity was reported by Masuda et al. in 1971 [56]. Oxatriazole-5-imines (9) have been reported to be an important class of NO donors and potent antiplatelet, fibrinolytic, thrombolytic, and bronchiectatic agents [57]. However, an extensive investigation of the NO-releasing and other biologi-... 

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