Mechanistic insight into exclusive nitric oxide recovery from a carbon-bound diazeniumdiolate.
We report that NaON=N(O)-X-N(O)=NONa (1), where X is para-disubstituted benzene, hydrolyzes to 2 mol of nitric oxide (NO) with concurrent production of 1 mol of p-benzoquinone dioxime at physiological pH. The reaction is acid catalyzed, with a rate that slows as the substrate concentration is increased. The results demonstrate that a carbon-bound diazeniumdiolate can be quantitatively hydrolyzed to produce NO as the only gaseous nitrogen-containing product. The data also suggest that N-N bond cleavage is the rate-determining step in NO release, since C-N cleavage followed by dissociation of O=N-N=O to two NO molecules cannot be operative in this case. The finding that this oxime can absorb NO in organic media and regenerate it quantitatively at physiological pHs extends the potential pharmacological implications of the carbon-bound diazeniumdiolates.
Arnold
Ernst V
EV
Chemistry Section, Laboratory of Comparative Carcinogenesis, National Cancer Institute at Frederick, Frederick, MD 21702, USA.
Citro
Michael L
ML
Saavedra
Evelyn A
EA
Davies
Keith M
KM
Keefer
Larry K
LK
Hrabie
Joseph A
JA
D001391:Azo Compounds / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D005740:Gases / Q000737:chemistry; D006207:Half-Life; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008163:Luminescent Measurements; D015394:Molecular Structure; D009569:Nitric Oxide / Q000737:chemistry*
D001391:Azo Compounds; D005740:Gases; C452539:diazeniumdiolate; D009569:Nitric Oxide; D002244:Carbon