Nitroprusside

Sodium nitroprusside (SNP), which is also known as Nipruss or Nipride to medical practitioners, was the first iron nitrosyl complex, prepared as far back as 1850 by Playfair [40]. The hypotensive property of SNP was first demonstrated by Johnson [41] in 1929. It was shown that application of a moderate dose of SNP reduces the blood pressure of a severely hypertensive patient without any side effect [42]. Since that time considerable research has been carried out to understand the mode of action of nitroprusside and its metabolic fate. SNP is now regarded as a potent vasodilator that causes muscle relaxation by releasing NO which activates the cytosolic isozyme of guanylyl cyclase [43-46]. 

SN P spontaneously releases N O both thermally and photochemically [61-65], but is quite stable in the dark and in aqueous in vitro physiological media [66]. This implies that absorption of heat and light energy induces electron transfer from the Fe2+ center to the N 0+ ligand, resulting in weakening of the Fe-N O bond and subsequent release of NO [65]. SNP also decomposes in an aqueous environment in the presence of biological reductants [65, 66] and some transition metal ions to produce nitric oxide. 

which has been the common feature for the decomposition of S-nitrosothiols [72-77]. 

Only freshly prepared nitroprusside should be administered, and the container should be covered with lightproof materials, since they are decomposed upon exposure to light. Solutions may be discolored due to the presence of organic and inorganic substances and must not be used. Preservatives, such as sodium bisulfate and hydroxy benzoates, reduce the stability of nitroprusside.124 126 

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Note cautiously the characteristic odour of acetaldehyde which this solution possesses. Then with the solution carry out the following general tests for aldehydes described on p. 341 Test No. I (SchiflF s reagent). No. 3 (Action of sodium hydroxide). No. 4 (Reduction of ammoniacal silver nitrate). Finally perform the two special tests for acetaldehyde given on p. 344 (Nitroprusside test and the Iodoform reaction). 

To 2 ml. of a freshly prepared dilute aqueous solution of sodium nitroprusside, add 2 drops of ethyl malonate and shake then add 2-3 drops of 10% aqueous sodium hydroxide solution and shake again. A red coloration at once appears, but fades in a few minutes to pale brown,... 

Sulphur. THE LASSAIGNE SODIUM TEST. The sodium fusion will have converted any sulphur present in the original compounds to sodium sulphide. Dissolve a few crystals of sodium nitroprusside, Na8[Fe(CN)5NO],zH20, in water, and add the solution to the third portion of the filtrate obtained from the sodium fusion. A brilliant purple coloration (resembling permanganate) indicates sulphur the coloration slowly fades on standing. Note, (i) Sodium nitroprusside is unstable in aqueous solution and therefore the solution should be freshly prepared on each occasion, (ii) This is a very delicate test for sulphides, and it is essential therefore that all apparatus, particularly test-tubes, should be quite clean. 

Nitroprusside reaction. Add 1 ml. of a freshly prepared solution of sodium nitroprusside to the aldehyde or its solution. Add dil. NaOH solution in excess a red coloration is produced. 

Gives some of the tests for acetaldehyde, but more feebly e.g., it restores the colour to SchifF s reagent, gives a yellow resin with NaOH, and responds to the nitroprusside test. With ammoniacal AgN03, it gives a silver minor only after 2 -3 minutes warming. It does not give the iodoform reaction. 

The coioration is caused by the comersion of acetone by alkali to the CHjCOCHa " ion, which then reactswith the nitroprusside ion [FefCNlsNO]"- giving the highly coloured ion [Fe(CN)sNO-CHiCOCH3] ... 

Sulphuric add test. Heat 0 5 g. of citric acid or a citrate with 1 ml. of H2SO4 CO and COg are evolved and the mixture turns yellow, but does not char. Acetone dicarboxylic acid, OC(CH2COOH)g, is also formed, and is tested for after heating the mixture for 1 minute cool, add a few ml. of water and make alkaline with NaOH solution. Add a few ml. of a freshly prepared solution of sodium nitroprusside and note the intense red coloration (see Test 4 a) for ketones, p. 346). 

Now add a few drops of a freshly prepared solution of sodium nitroprusside. A purple coloration is obtained (test for - SH Group),... 

Special Tests (i) Nitro-prusside + NaOH (red). (ii) Iodoform Nitroprusside + NaOH (red) (1) NaHSOs, immediate ppt. (i) FeCls (violet) (ii) NaHSOj, ppt. on standing. 

Sodium Nitroprusside. Dissolve a few crystals in water as required. 

Nantokite, see Copper(I) chloride Natron, see Sodium carbonate Naumannite, see Silver selenide Neutral verdigris, see Copper(H) acetate Nitre (niter), see Potassium nitrate Nitric oxide, see Nitrogen(II) oxide Nitrobarite, see Barium nitrate Nitromagnesite, see Magnesium nitrate 6-water Nitroprusside, see Sodium pentacyanonitrosylfer-rate(II) 2-water... 

Sodium nitroprusside (for sulfur detection) dissolve about 1 g of sodium nitroprusside in 10 mL of water as the solution deteriorates on standing, only freshly prepared solutions should be used. This compound is also called sodium nitroferricyanide and has the formula Na2pe(NO)(CN)5 2H2O. 

Nitroprusside. Nitropmsside is a poteat, fast-actiag vasodilator that has to be administered iatravenously by iafusion. It relaxes arterial and venous vascular smooth muscle. Its use is mainly ia hyperteasive crises. Its effects terminate as sooa as iafusioa of the dmg is stopped. 

Sodium Nitroprusside Sodium Nitrate Sodium Sulphite... 

The silica dispersion showed the smallest retention volume. It should be noted, however, that the authors reported that the silica dispersion required sonicating for 5 hours before the silica was sufficiently dispersed to be used as "pseudo-solute". The retention volume of the silica dispersion gave the value of the kinetic dead volume, /.e., the volume of the moving portion of the mobile phase. It is clear that the difference between the retention volume of sodium nitroprusside and that of the silica dispersion is very small, and so the sodium nitroprusside can be used to measure the kinetic dead volume of a packed column. From such data, the mean kinetic linear velocity and the kinetic capacity ratio can be calculated for use with the Van Deemter equation [12] or the Golay equation [13]. 

Sulphur.—The presence of sulphur in organic compounds may be detected by heating the substance with a little metallic sodium or potassium. The alkaline sulphide, when dissolved in water, gives a violet colouration with a solution of sodium nitro-prusside. Heat a fragment of gelatine with a small piece of potassium in a test-tube until the bottom of the tube is red hot, and place it m a small beaker of water as described in the test for nitrogen (p. 2). Filter the liquid and add a few drops of sodium nitroprusside solution. 

Some of these reactions result, essentially, in the oxidative addition of N0" N03 to coordinatively unsaturated metal centres whereas in others ligand replacement by NO+ occurs — this is a favoured route for producing nitroprusside , i.e. nitrosylpentacyanoferrate(II) ... 

These, and related, iron nitrosyl compounds have excited considerable interest because of their biological activity.Nitroprusside induces muscle relaxation and is therefore used to control high blood pressure. Roussin s black salt has antibacterial activity under conditions relevant to... 

Nitro-prussidnatrium, n. sodium nitroprusside. -prussidwasserstoffsaure,/. nitroprussic acid, -pulver, n. nitro powder. 

Color reaction Positive Ninhydrin, Nitroprusside-reagent, Br2-H20, Lemieux, and Negative Tollens, Molish, Sakaguchi, Elson-Morgan, Ferric chloride. Ultraviolet End absorption. 

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