Salicylate Ion Research Articles

STUDY OF ANION EXCHANGE EXTRACTION OF SOME ANIONIC COMPLEXES OF IRON (III) BY ORGANIC SOLUTIONS OF QUADERIC AMMONIUM SALTS

The anion-exchange extraction of salicylate, thiosulphate and thiocyanate iron (III) complexes by solutions of quaternary ammonium salts (QAS) chlorides in organic solvents (toluene, carbon tetrachloride, ethyl acetate, isobutyl alcohol, nitrobenzene) was studied. The composition of the iron (III) anionic complexes was established by the analysis of the calibration curves E = f (pCFe (III)) constructed from iron (III) solutions against the background of various contents of thiocyanate, thiosulphate and salicylate ions and the steepness of the electrode function. As an indicator electrode was used the ion-selective electrode with a membrane, which based on a nitrobenzene solution of tetradecylammonium bromide. The solution containing of alkyldimethylbenzylammonium chloride and alkyldimethylethylbenzylammonium chloride and the corresponding organic solvent were mixed in a ratio 1: 1. An organic layer containing the QAS was selected. The anion-exchange extraction was provided in contact with aqueoses solutions of Fe(III) anionic complexes. The extraction process is estimated quantitatively using a distribution coefficient (D), the value of D is calculated taking into account the iron (III) concentration in the aqueous phase before and after extraction. The content of iron (III) in solutions is determined spectrophotometrically (λ = 440 nm). It is established that the value of the distribution coefficient depends on the permittivity (ε) of the organic solvent. In the row toluene - carbon tetrachloride - ethyl acetate - isobutyl alcohol - nitrobenzene, the permittivity increases. In the same sequence, D increases for all studied complex iron(III) ions. Moreover, a decrease in the concentration of the extracted particle leads to an insignificant decrease the value of the distribution coefficient. The composition and stability of the complex iron (III) ion have a significant effect on the extraction activity.

Bile salt-induced permeability changes in the isolated rat intestine.

SummaryPhysiologic concentrations of the conjugated bile salt, sodium taurodeoxycholate, markedly increased the permeability of the everted rat small intestine to salicylate ion. Addition of egg lecithin or oleic acid and glyceryl monooleate to the medium diminished this effect and prevented changes in the gross appearance of the intestinal mucosa which occurred when the isolated intestine was exposed to the bile salt alone.

Solvent extraction of salicylates-III: The distribution of trivalent cations between aqueous solution and tributyl phosphate in the presence of salicyclic acid

The distribution of iron(III), aluminium(III), and promethium(III) between TBP and aqueous solution in the presence of salicyclic acid has been examined. Both iron(III) and aluminium(III) which exist in aqueous solution as chelates with the doubly-charged salicylate ion extract as species of the type M(C 7H 4O 3(C 7H 5O 3). Promethium(III) which shows little tendency to chelate extracts as Pm(C 7H 5O 3) 3.

Sodium salicylate iontophoresis in the treatment of plantar warts.

The management of the plantar wart has long been a perplexing problem. Treatments that have been used include surgical diathermy, electrolysis, cautery, solid carbon dioxide, roentgen rays, and ultrasound. Because 10 percent salicylic acid in collodion has also proved to be of value, it was hypothesized that salicylate ions might be introduced by means ofcommon ion transfer. Salicylate iontophoresis was found to be quite effective in the treatment of five patients.

Solvent extraction of pyridine complexes of copper(II)

Copper(II) is extracted into chloroform by pyridine in the presence of bromide, chloride, perchlorate, and salicylate ions. At pyridine concentrations between 10 −2 and 10 −1 M the extracted species have the formula Cu py 2 X 2. At higher pyridine concentrations both Cu py 3 X 2 and Cu py 4 X 2 appear to be extracted. The partition data confirms the existence of the dimer Cu 2 py 4(OH) 2 2+ in the aqueous phase at pH > 7.

Effect of combination of pharmaceuticals on gastrointestinal absorption. II. Combination of caffeine with non-absorbable drugs.

The effect of combination of caffeine with a few absorbable drugs (salicylic acid, dehydroacetic acid, aspirin, and ethyl p-hydroxybenzoate) on gastric absorption by rabbit was investigated. It is well-known that these drugs associate with caffeine to form soluble complexes. The experimental results at pH 1.3 showed that there was a proportional relationship between the apparent absorption rate constants for drugs and the existing ratio of complex in administered solution, and the effect of caffeine on drugs absorption was remarkable for more absorbable drug (eg. dehydroacetic acid) but was so little for poorly absorbable drug (eg. aspirin). On the other hand, it bacame clear that the absorption rate of salicylate ion was not affected with caffeine. This fact may be correlated with the different affinity between salicylate ion and caffeine as compared with that of undissociated salicylic acid.

Mechanism of decarboxylation of substituted salicylic acids. II. Kinetics and 13C-carboxyl kinetic isotope effects in nitrobenzene–quinoline mixtures

The decarboxylation of 4-methylsalicylic acid in dilute solutions of quinoline in nitrobenzene at 200 °C is first order with respect to the salicylic acid and first order with respect to quinoline. The pseudo-first-order rate constant reaches a maximum at 0.25 M quinoline, then decreases as the quinoline concentration increases. The 13C-carboxyl kinetic isotope effect, 100(k12/k13 − 1), is 2.2% in pure quinoline and 0.7% in 0.02 M quinoline. It is therefore concluded that the mechanism proposed in Part I of this series involves three steps: ionization of the salicylic acid to a quinolinium salicylate ion pair, reversible protonation by quinolinium ion of the salicylate ion at carbon 1 of the aromatic ring, and loss of carbon dioxide from the protonated salicylate ion. In dilute quinoline solution the second step is slow, while in pure quinoline the third step becomes rate determining.

Effect of combination of pharmaceuticals on gastrointestinal absorption. I. Combination of caffeine with a few absorbable drugs.

The effect of combination of caffeine with a few absorbable drugs (salicylic acid, dehydroacetic acid, aspirin, and ethyl p-hydroxybenzoate) on gastric absorption by rabbit was investigated. It is well-known that these drugs associate with caffeine to form soluble complexes. The experimental results at pH 1.3 showed that there was a proportional relationship between the apparent absorption rate constants for drugs and the existing ratio of complex in administered solution, and the effect of caffeine on drugs absorption was remarkable for more absorbable drug (eg. dehydroacetic acid) but was so little for poorly absorbable drug (eg. aspirin). On the other hand, it bacame clear that the absorption rate of salicylate ion was not affected with caffeine. This fact may be correlated with the different affinity between salicylate ion and caffeine as compared with that of undissociated salicylic acid.

Interaction of sodium and calcium salicylates with cationic surfactants

Sodium and calcium salicylates have been found to interact with surfactants of the quaternary ammonium type in much the same way as salicylic acid, as stated in a previous report. The interaction produces a marked change in viscosity which increases with salicylate concentration until the system becomes a gel. This increase in viscosity is not related to pH and is reduced with a rise in temperature. This complex interaction is probably due to attraction between the salicylate ion and the cation of the surfactant molecule leading to an increase in size of the surfactant molecule resulting in a rise in viscosity. The change in viscosity is further enhanced by an increase in the electrical charges in the system brought about by the addition of sodium salts, the order of effectiveness of the anion being as follows: citrate > phosphate > sulfate > carbonate > bromide > (except at low concentration) chloride, and by the addition of various sulfates, the order of effectiveness of the cation being as follows: sodium > potassium > ammonium > magnesium > zinc. Phenyl, ethyl, and methyl salicylates fail to show this complex interaction due to the absence of salicylate ion in aqueous solution. In addition, sodium lauryl sulfate and cetomacrogol 1000 do not demonstrate any change in viscosity in the presence of both salicylates. Sodium and calcium salicylates have been found to interact with surfactants of the quaternary ammonium type in much the same way as salicylic acid, as stated in a previous report. The interaction produces a marked change in viscosity which increases with salicylate concentration until the system becomes a gel. This increase in viscosity is not related to pH and is reduced with a rise in temperature. This complex interaction is probably due to attraction between the salicylate ion and the cation of the surfactant molecule leading to an increase in size of the surfactant molecule resulting in a rise in viscosity. The change in viscosity is further enhanced by an increase in the electrical charges in the system brought about by the addition of sodium salts, the order of effectiveness of the anion being as follows: citrate > phosphate > sulfate > carbonate > bromide > (except at low concentration) chloride, and by the addition of various sulfates, the order of effectiveness of the cation being as follows: sodium > potassium > ammonium > magnesium > zinc. Phenyl, ethyl, and methyl salicylates fail to show this complex interaction due to the absence of salicylate ion in aqueous solution. In addition, sodium lauryl sulfate and cetomacrogol 1000 do not demonstrate any change in viscosity in the presence of both salicylates.

Properties of organic-water mixtures. IV. The effect of various salts on the miscibility gap of the glycerol triacetate-water system

The effect of various salts on the miscibility gap of the glycerol triacetate (GTA)water system was examined at 25°C. Whereas addition of NaCl and KC1 reduces the mutual solubility of GTA and water, the addition of certain other salts, e.g., perchlorates, thiocyanates, iodides, bromides, salicylates, and zinc chloride, increases the mutual solubility of GTA and water to such an extent that complete miscibility may result. For the anions listed the “salting-in” effects are, in general, insensitive to the cation used or its charge. Plots of equivalents of salt required to produce miscibility vs. wt. percent GTA showed curves with maxima usually at about 40% GTA. Miscibility at the maximum required ca. 1 mole of perchlorate or salicylate ions per kilogram of solvent; for thiocyanates, iodides, bromides, and zinc chloride, the corresponding concentrations were usually larger. For several salts measurements were made in the temperature range 2° to 75°C. The mutual solubility of GTA and water in the absence of salts increases slightly with increasing temperature. Less NaC 7H 5O 3 was required for miscibility at a higher temperature. However, for Mg(ClO 4) 2, KCNS, NaI, and CdBr 2, more salt was required for miscibility at a higher temperature.

Fluorescence of some substituted benzenes.

SOME mono- and di-substituted benzenes fluoresce in aqueous solution. Phenol, for example, fluoresces in the ultra-violet and the salicylate ion in the visible region of the spectrum. Williams1 pointed out that the fluorescent mono-substituted benzenes were those containing the classical ortho-para-directing groups. We have now examined this phenomenon more closely and also determined the quantum efficiency of fluorescence using a commercial Aminco-Bowman spectrophotofluorimeter.

The action of sodium salicylate and related compounds on the proteins of the groundnut (Arachis hypogaea)

AbstractThe action of sodium salicylate on arachin and conarachin II has been investigated by viscosity and sedimentation velocity techniques. Considerable evidence for the occurrence of aggregation of the protein has been obtained. It appears that the salicylate ion first penetrates the protein molecule causing a modification of the internal linkages resulting in an opening up of the molecule. This would lead to the exposure of many more active groups which probably then react with active groups on other molecules. The effect of the salicylate ion was more pronounced at lower pH values (ca. 6‐7) and higher ionic strengths (ca. 1.0). Considerably greater effects were observed with conarachin II than with arachin, indicating that the arachin molecule is probably more strongl bound internally. The effect of a number of other sodium salts of organic acids on conarachin II was examined, and it appears that the action of any organic anion depends on the nonpolar portion of the molecule as well as on the polar groups.

A Colorimetric Comparison of Plasma-Salicylate Levels Following the Oral Administration of Certain Salicylates to Rabbits

A new analgetic tablet, designated as the P-tablet, has been compared with aspirin and two well-known analgetic tablets. Each tablet contains a source of salicylate ion and the dose of each drug has been calculated on the basis of salicylate equivalents; this permitted a fair evaluation of the resultant plasma-salicylate levels. Plasma-salicylate levels have been used as an index of their therapeutic activity. The influence of the various components of each tablet on the rate of absorption has, in effect, been compared to the rate of absorption of aspirin alone. The plasma- salicylate concentrations have been determined colorimetrically and evaluated by significance tests for multiple contrasts in the analysis of variance. The analyses show that significantly higher plasma-salicylate levels are obtained from the P-tablet than from Bufferin®, Anacin® or aspirin, at five and ten minutes after administration.

Investigation of Some Complexes Formed in Solution by Caffeine : III. Interactions Between Caffeine and Aspirin, p-Hydroxybenzoic Acid, m-Hydroxybenzoic Acid, Salicylic Acid, Salicylate Ion, and Butyl Paraben

The equilibrium reactions leading to complex formation between caffeine and six pharmaceuticals have been studied. The stability constants at several temperatures, the heats of reaction, and the entropy changes have been approximated. It is shown that complex formation may lead to either a decrease or an increase in the solubilities of the reactants. The influence of structure on equilibrium is also discussed.

PHYSICAL AND CHEMICAL PROPERTIES OF GLUTEN I. ESTIMATION OF MOLECULAR PROPERTIES USING ELECTROPHORETIC AND DIFFUSION DATA

The molecular characteristics of gluten in sodium salicylate solutions have been studied by means of diffusion and electrophoretic techniques. The results of the observations indicate that gluten in sodium salicylate is electrostatically homogeneous with a high mean negative valence of 34 and therefore a high surface charge density. The isoelectric point of gluten in this dispersing agent is below pH 4.0. This low value of the isoelectric point and the high valence of the protein molecule is probably due to selective adsorption of salicylate ions on gluten. The particles in the fraction of gluten molecularly dispersed in 0 5 μ sodium salicylate are prolate ellipsoids of revolution of the order of 25 Å in diameter and 400 to 450 Å long. These are mean values as the molecularly dispersed particles are not uniform in mass. When they are aggregated it is side by side association rather than end to end. The density of dehydrated gluten is 1.291 gm. per cc. Qualitative evidence is given for the view that the degree of hydration of gluten particles is probably not great.

Some Effects of Salicylate on Plant Viruses

DURING an investigation into the effects of various anions on the precipitation of the paracrystalline solid phase of tobacco mosaic virus nucleoprotein (Marmor tabaci, var. vulgare, Holmes) from its solution in water, the salicylate ion was found to behave differently from other anions. For each salt there was found a critical concentration at and above which the virus was precipitated from solution in the form of spontaneously birefringent microtactoids or fibres. The white precipitate of virus nucleoprotein is still fully infective and may be redispersed to give a clear solution by mechanical agitation or dilution as described previously1. However, the precipitate produced by solutions of potassium salicylate at concentrations above 0.46M. is very different in character from that obtained with other salts. It consists of an insoluble, amorphous, white, granular solid deposit of denatured protein. Mechanical agitation or dilution does not cause re-solution. At the same time the virus loses its infectivity irreversibly. The accompanying graph illustrates the rate of inactivation of a 0.2 per cent solution of the pure virus by 1.0M. potassium salicylate at pH. 7 and 30° C. The straight line nature of curve Bindicates that the rate of inactivation is logarithmic. The rate of inactivation is greater the greater the concentration of salicylate and is markedly influenced by the temperature. With solutions of salicylate of the order of half molar there is only a partial inactivation, and a steady state appears to be set up after a few hours. At a concentration of 1.0M. there is no loss of infectivity, of stream double refraction or solubility after a contact of forty-eight hours. Denaturation, loss of stream double refraction and of infectivity all run parallel.