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[reaction: see text] The enediamine tautomer of a variety of substituted amidine free bases reacts with nitric oxide (NO) to produce compounds containing a carbon-bound diazeniumdiolate [R1R2R3C-N(O)=NO-] functional group (previously called "nitrosohydroxylamines"). The new reaction has been shown to be quite general, although the nature of the products does vary. Amidines containing more than one replaceable hydrogen produce polydiazeniumdiolates as intermolecular salts, while those in which only one diazeniumdiolation can occur provide zwitterionic salts. These diazeniumdiolated amidines are shown to be useful NO donor compounds which undergo very slow spontaneous dissociation on dissolution in pH 7.4 phosphate buffer to produce mixtures of NO and nitrous oxide containing mostly NO. The most advantageous manifestation of the new discovery is the preparation of the monodiazeniumdiolated amidine zwitterions. Reaction of the medically relevant alpha-adrenergic agonists tetrahydrozoline and idazoxan produced monodiazeniumdiolated amidine zwitterions from which NO release was observed for up to 28 days and showed little sign of ending. The reaction should be applicable to a variety of pharmaceutical agents, including NO synthase inhibitors, antitumor agents, and antibacterials.

The effect of surfactant micelles on the acid-catalyzed dissociation of NO from diazeniumdiolate ions of structure R1R2N[N(O)NO]- has been examined in phosphate-buffered solutions at 37 °C. The reaction behavior of zwitterionic substrates [2, R1 = R2 = H2N(CH2)2; 3, R1 = R2 = H2N(CH2)3; 4, R1 = n-Pr, R2 = H2N(CH2)3; 5, R1 = H2N(CH2)3, R2 = H2N(CH2)3NH(CH2)4] and anionic substrates [1, R1 = R2 = Et; 6, R1 = R2 = n-Pr] has been compared. All but DEA/NO (1) are catalyzed by anionic micelles of sodium dodecyl sulfate (SDS) but are unaffected by the presence of cationic cetyltrimethylammonium bromide or the zwitterionic surfactant 3-(N-dodecyl-N,N-dimethylammonio)-1-propanesulfonate (lauryl sulfobetaine). Catalysis by sodium decylphosphonate micelles has also been demonstrated for 2 (DETA/NO). The surfactant-mediated catalysis is discussed in terms of a distribution model with simultaneous reaction in the water and micellar pseudophases. Binding constants (Ks) for diazeniumdiolate association with the surfacta...

Despite over a century of reports to the contrary, sodium methoxide has been found to react with nitric oxide (NO). The reaction, whose final organic product is sodium formate, is postulated to occur via an intermediate O-bound diazeniumdiolate [CH3O-N(O)=NO-] that decomposes to formaldehyde and nitrous oxide. Sodium formate forms from the aldehyde via a Cannizzaro reaction. Carboxylate salts have similarly been obtained by exposing sodium benzylate and sodium neopentoxide to NO in dioxane solution. Accordingly, sodium trimethylsilanoate should be considered as a substitute for sodium methoxide as the base used to accomplish the replacement of active hydrogens by the diazeniumdiolate functional group via the Traube reaction.

High-performance liquid (HPLC) and thin-layer (TLC) chromatographic methods for the detection and quantification of diazeniumdiolates are described. The HPLC determinations were made using a Rocket Platinum NH2 column (7 x 53 mm, 100-A pore size, 3-microm particle size), under isocratic conditions with mixtures of acetonitrile, methanol, and water containing 0.1% diethylamine (v/v), at a flow rate of 2.5 ml/min, a column temperature of 22 degrees C, and UV detection at 250 nm. The TLC determinations were similarly made using Merck NH2 F254S precoated glass plates (approximately 2 x 5 cm, 5-microm particle size, 0.2-mm layer thickness) with mixtures of acetonitrile, methanol, and water containing 0.1% diethylamine (v/v). Preexisting traces of carcinogenic nitrosamines were detected in some samples of diazeniumdiolates. The methods provide a more efficient means of characterizing the purity of diazeniumdiolate samples prepared for use in biomedical applications than older procedures which rely on differential absorbance measurements at 250 and 350 nm, respectively.

In contrast to amidines bearing ionizable alpha-CH bonds, which react with nitric oxide (NO) to add diazeniumdiolate groups at their alpha-carbons, benzamidine forms an N-bound diazeniumdiolate that can be further derivatized at the other amidine nitrogen and/or the terminal oxygen to form caged NO compounds as potential NO prodrugs.

Preuves de la presence de l'ion Me 2 N(H)NO + dans les solutions aqueuses de (dimethyl nitroso) amine a pH≤2

Preuves de la presence de l'ion Me 2 N(H)NO + dans les solutions aqueuses de (dimethyl nitroso) amine a pH≤2