Acyloxy nitroso compounds as nitroxyl (HNO) donors: Kinetics, reactions with thiols, and vasodilation properties

Academic Article

Abstract

  • Acyloxy nitroso compounds hydrolyze to nitroxyl (HNO), a nitrogen monoxide with distinct chemistry and biology. Ultraviolet-visible spectroscopy and mass spectrometry show hydrolysis rate depends on pH and ester group structure with the observed rate being trifluoroacetate (3) > acetate (1) > pivalate (2). Under all conditions, 3 rapidly hydrolyzes to HNO. A combination of spectroscopic, kinetic, and product studies show that addition of thiols increases the decomposition rate of 1 and 2, leading to hydrolysis and HNO. Under conditions that favor thiolates, the thiolate directly reacts with the nitroso group, yielding oximes without HNO formation. Biologically, 3 behaves like Angeli's salt, demonstrating thiol-sensitive nitric oxide-mediated soluble guanylate cyclase-dependent vasorelaxation, suggesting HNO-mediated vasorelaxation. The slow HNO-donor 1 demonstrates weak thiol-insensitive vasorelaxation, indicating HNO release kinetics determine HNO bioavailability and activity. These results show that acyloxy nitroso compounds represent new HNO donors capable of vasorelaxation depending on HNO release kinetics. © 2011 American Chemical Society.
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    Digital Object Identifier (doi)

    Author List

  • Shoman ME; Dumond JF; Isbell TS; Crawford JH; Brandon A; Honovar J; Vitturi DA; White CR; Patel RP; King SB
  • Start Page

  • 1059
  • End Page

  • 1070
  • Volume

  • 54
  • Issue

  • 4