Dual mechanisms of HNO generation by a nitroxyl prodrug of the diazeniumdiolate (NONOate) class

Daniela Andrei, Debra J. Salmon, Sonia Donzelli, Azadeh Wahab, John R. Klose, Michael L. Citro, Joseph E. Saavedra, David A. Wink, Katrina M. Miranda, Larry K. Keefer

Research output: Contribution to journalArticlepeer-review

49 Scopus citations


Here we describe a novel caged form of the highly reactive bioeffector molecule, nitroxyl (HNO). Reacting the labile nitric oxide (NO)- and HNO-generating salt of structure iPrHN-N(O)=NO-Na+ (1, IPA/NO) with BrCH2OAc produced a stable derivative of structure iPrHN-N(O)=NO-CH2OAc (2, AcOM-IPA/NO), which hydrolyzed an order of magnitude more slowly than 1 at pH 7.4 and 37 °C. Hydrolysis of 2 to generate HNO proceeded by at least two mechanisms. In the presence of esterase, straightforward dissociation to acetate, formaldehyde, and 1 was the dominant path. In the absence of enzyme, free 1 was not observed as an intermediate and the ratio of NO to HNO among the products approached zero. To account for this surprising result, we propose a mechanism in which base-induced removal of the N-H proton of 2 leads to acetyl group migration from oxygen to the neighboring nitrogen, followed by cleavage of the resulting rearrangement product to isopropanediazoate ion and the known HNO precursor, CH3-C(O)-NO. The trappable yield of HNO from 2 was significantly enhanced over 1 at physiological pH, in part because the slower rate of hydrolysis for 2 generated a correspondingly lower steady-state concentration of HNO, thus, minimizing self-consumption and enhancing trapping by biological targets such as metmyoglobin and glutathione. Consistent with the chemical trapping efficiency data, micromolar concentrations of prodrug 2 displayed significantly more potent sarcomere shortening effects relative to 1 on ventricular myocytes isolated from wild-type mouse hearts, suggesting that 2 may be a promising lead compound for the development of heart failure therapies.

Original languageEnglish (US)
Pages (from-to)16526-16532
Number of pages7
JournalJournal of the American Chemical Society
Issue number46
StatePublished - Nov 24 2010

ASJC Scopus subject areas

  • Catalysis
  • General Chemistry
  • Biochemistry
  • Colloid and Surface Chemistry


Dive into the research topics of 'Dual mechanisms of HNO generation by a nitroxyl prodrug of the diazeniumdiolate (NONOate) class'. Together they form a unique fingerprint.

Cite this