Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The toxicity of Cd2+ in Escherichia coli K-12 was potentiated by salicylate and several related compounds. The efficiency of plating on Luria broth plates was reduced by more than 10(5)-fold when 10 mM salicylate and 200 microM CdCl2 were present simultaneously but was unaffected when either compound was present by itself. Synergistic effects were found at pH 7.4 with certain other weak acids (acetyl salicylate [aspirin], benzoate, and cinnamate) and with a nonacidic salicylate analog, salicyl alcohol, but not with acetate or p-hydroxy benzoate. Thus, the synergism with Cd2+ is determined by the structure of the compounds and not merely by their acidity. The kinetics of 109Cd2+ uptake by cells grown and assayed in broth indicated the presence of two uptake systems with Kms of 1 and 52 microM Cd2+ and Vmaxs of 0.059 and 1.5 mumol of Cd2+ per min per g of cells, respectively. The kinetics of uptake for cells grown and assayed with 20 mM salicyl alcohol showed 2.5-fold increases in the Vmaxs of both systems but no change in the Kms. Salicylate-grown cells also exhibited increased rates of 109Cd2+ uptake by both systems. Thus, enhanced uptake of Cd2+ may be responsible for the potentiation of Cd2+ toxicity by salicylate and salicyl alcohol.
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PMID:Potentiation by salicylate and salicyl alcohol of cadmium toxicity and accumulation in Escherichia coli. 208 94

The study included 18 school-age and adolescent patients with juvenile rheumatoid arthritis who had consumed from 351 to 6393 gm. (average 2813 gm.) as total dose for the control of their disease. All of them underwent a complete physical examination, general laboratory tests and as specific tests of renal function; urinalysis, urine culture, endogenous creatinine clearance, Addis count (red and white cells), sodium and potassium urinary excretion, urinary acidity capacity, administration of ammonium chloride and capacity of urinary concentration following water restriction. Normal results in practically all parameters led to conclude that a clear evidence of nephropathy due to salicylic acid consumption, was not found in any of the patients studied.
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PMID:[Evaluation of nephropathies in children with rheumatoid arthritis and prolonged therapy with salicylates]. 699 Sep 41

Copper complexes of phenols related to salicylic acid were prepared in DMSO and applied to the shaved dorsal skin of rats. The following activities were assayed: (i) suppression of the carrageenan or hydroxylapatite paw oedemas; (ii) reduction of chronic inflammation in established adjuvant arthritis; (iii) local skin toxicity. Cu(II) was an essential component. Some limited structure-activity correlations were made among alternative cupriphores. DMSO solutions of copper complexes were more potent than their solutions in ethanol. Glycerol was a beneficial additive. Reducing the acidity of some copper salicylate formulations also reduced their potency. Niflumic acid and phenylbutazone were effective non-salicylate transcutaneous cupriphores.
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PMID:Lipophilic copper(II) formulations: some correlations between their composition and anti-inflammatory/anti-arthritic activity when applied to the skin of rats. 708 Sep 60

A series of antimycin A analogues was synthesized by modifying the salicylic acid moiety, whereas the portion of the molecule corresponding to the natural dilactone-ring moiety was fixed as di-n-octyl L-glutamate. To probe the structure of the antimycin A binding site, the structural factors of the salicylic acid moiety required for inhibitory action were examined by means of structure-activity studies with intact rat-liver mitochondria and the cytochrome bc1 complex isolated from bovine heart mitochondria. As suggested earlier (Rieske, J.S. (1976) Biochim. Biophys. Acta 456, 195-247), the phenolic OH was very important for inhibition. For the derivatives which do not possess a formylamino group in the 3-position (ortho to the phenolic OH), the inhibitory activity tended to increase as the electron-withdrawing property of the substituent increased, i.e., as the acidity of the phenolic OH group increased. This indicates that the acidity of the phenolic OH is an important factor governing inhibition. While the electron-withdrawing property of the formylamino group itself is rather poor, 3-formylamino derivatives elicited potent activity. The conformation of the 3-formylamino group was also found to be a very important factor in establishing inhibitory activity. In addition, the bulkier the moiety corresponding to the 3-formylamino group, the lower the activity. These results demonstrate that the presence of the 3-formylamino group, and its proper conformation, are needed for a close fitting of antimycin A to its binding domain. Although the inhibitors that lack a 3-formylamino group retained fairly potent activity, their effects on the reduction of cytochromes b and c1 were somewhat different from those of natural antimycin A, indicating that the 3-formylamino group is essential for inhibitor binding to the cytochrome bc1 complex in the same manner as natural antimycin A. It is concluded that both the 3-formylamino group and the phenolic OH of antimycin A make important contributions to specific interactions with the amino acid residues of the cytochrome b.
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PMID:Structural factors of antimycin A molecule required for inhibitory action. 818 Feb 32

Three nitrophenol isomer-imprinted polymers were prepared under the same conditions using 4-vinylpyridine as a functional monomer. Different recognition capacities for template molecules were observed for the three polymers. Another imprinting system with stronger acidity than nitrophenol isomers, 2-hydroxybenzoic acid (salicylic acid) and 4-hydroxybenzoic acid, was imprinted using 4-vinylpyridine or acrylamide as functional monomer respectively. Both 4-hydroxybenzoic acid-imprinted polymers using the two monomers showed recognition ability for the template molecule. However, when acrylamide was chosen as functional monomer, the salicylic acid-imprinted polymer showed very weak recognition for the template molecule, whereas strong recognition ability of the resultant polymer for salicylic acid was observed with 4-vinylpyridine as functional monomer. It seems that the structure and acidity of template molecules is responsible for the difference in recognition, by influencing the formation and strength of interaction between template molecule and functional monomer during the imprinting process. An understanding of the mechanism of molecular imprinting and molecular recognition of MIPs will help to predict the selectivity of MIPs on the basis of template molecule properties.
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PMID:Molecular imprinting of nitrophenol and hydroxybenzoic acid isomers: effect of molecular structure and acidity on imprinting. 1473 32

The tetrahedral zinc complex [(Tp(Ph,Me))ZnOH] (Tp(Ph,Me) = hydrotris(3,5-phenylmethylpyrazolyl)borate) was combined with 2-thenylmercaptan, ethyl 4,4,4-trifluoroacetoacetate, salicylic acid, salicylamide, thiosalicylic acid, thiosalicylamide, methyl salicylate, methyl thiosalicyliate, and 2-hydroxyacetophenone to form the corresponding [(Tp(Ph,Me))Zn(ZBG)] complexes (ZBG = zinc-binding group). X-ray crystal structures of these complexes were obtained to determine the mode of binding for each ZBG, several of which had been previously studied with SAR by NMR (structure-activity relationship by nuclear magnetic resonance) as potential ligands for use in matrix metalloproteinase inhibitors. The [(Tp(Ph,Me))Zn(ZBG)] complexes show that hydrogen bonding and donor atom acidity have a pronounced effect on the mode of binding for this series of ligands. The results of these studies give valuable insight into how ligand protonation state and intramolecular hydrogen bonds can influence the coordination mode of metal-binding proteinase inhibitors. The findings here suggest that model-based approaches can be used to augment drug discovery methods applied to metalloproteins and can aid second-generation drug design.
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PMID:Using model complexes to augment and advance metalloproteinase inhibitor design. 1513 9

It has been found that salicylic acid can be removal effectively at the lower temperature of 140 degrees C on perovskite-type oxide LaFeO3 catalyst in the catalytic wet air oxidation (CWAO) process. Under the same condition, the activities for the CWAO of phenol, benzoic acid and sulfonic salicylic acid have been also investigated. The results indicated that, with compared to the very poor activities for phenol and benzoic acid, the activities for salicylic acid and sulfonic salicylic acid were very high, which are attributed to their same intramolecular H-bonding structures. With the role of hard acidity of intramolecular H-bonding, salicylic acid and sulfonic salicylic acid can be adsorbed effectively on the basic center of LaFeO3 catalyst and are easy to take place the total oxidation reaction. However, at temperatures higher than 140 degrees C, the intramolecular H-bonding structure of salicylic acid was destroyed and the activities at 160 and 180 degrees C decreased greatly, which confirms further the key role of intramolecular H-bonding in the CWAO. Moreover, the LaFeO3 catalyst also indicated a superior stability of activity and structure in CWAO of salicylic acid.
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PMID:Removal of salicylic acid on perovskite-type oxide LaFeO3 catalyst in catalytic wet air oxidation process. 1687 Mar 33

A new spectrophotometric titration method coupled with chemometrics for the simultaneous determination of mixtures of weak acids has been developed. In this method, the titrant is a mixture of sodium hydroxide and an acid-base indicator, and the indicator is used to monitor the titration process. In a process of titration, both the added volume of titrant and the solution acidity at each titration point can be obtained simultaneously from an absorption spectrum by least square algorithm, and then the concentration of each component in the mixture can be obtained from the titration curves by principal component regression. The method only needs the information of absorbance spectra to obtain the analytical results, and is free of volumetric measurements. The analyses are independent of titration end point and do not need the accurate values of dissociation constants of the indicator and the acids. The method has been applied to the simultaneous determination of the mixtures of benzoic acid and salicylic acid, and the mixtures of phenol, o-chlorophenol and p-chlorophenol with satisfactory results.
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PMID:Process monitored spectrophotometric titration coupled with chemometrics for simultaneous determination of mixtures of weak acids. 1745 33

3-Methyl-2-oxazolidone has been evaluated as a solvent for the titration of various weak carboxylic acids and phenols. Its high dielectric constant and wide liquid range contribute to its outstanding solvent properties. Tetrabutylammonium hydroxide was the titrant. End-points were determined potentiometrically with a glass-calomel electrode system. FORTRAN computer programs were used to evaluate the results, and relative acid strengths were determined and related to the aqueous acidity. The accuracies obtained are comparable to those for other solvent media. An 800-mV potential span is available in this solvent, which may allow differentiating titrations to be performed. No titrations of acid mixtures were attempted, but it was found possible to distinguish both neutralization steps for salicylic acid and o-phthalic acid.
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PMID:3-methyl-2-oxazolidone as a solvent for acid-base titrations. 1896 98

The phenol wastewater with high concentration was treated by hydroxyl radical produced by a strong ionization discharge plasma in the present article. Salicylic acid used as molecular probe to determine the concentration of hydroxyl radical. The phenol elimination efficiency of wastewater whose initial concentration was 1 21 5 mg x L(-1) could reach 99.11% when the concentration of hydroxyl radical was 1 037 mg x L(-1); while the initial concentration of 8 853 mg x L(-1) of phenol wastewater dropped to 6 250 mg x L(-1) under the same conditions, that is, 1 mg hydroxyl radicals could oxidize 2.5 mg of phenol. The smaller the initial phenol concentration, the higher the removal. However, the higher the initial concentration, the greater the absolute quantity of treatment. And the relation between the changes including pH value and the conductivity and the concentration of hydroxyl radical was stated and explained. With the concentration of hydroxyl radicals increasing, the pH value of wastewater changed from close to neutral to acidity gradually. The higher the concentration of hydroxyl radical, the stronger the acidity of wastewater. When continuing the increase in the concentration of hydroxyl radical, the change began to smooth. With the addition of hydroxyl radical, as is different from other phenomena, there was a tiny descending stage before ascending as shown on the conductivity curve, indicating that phenol had been oxidized and generated the organic acids continuously. Catechol, hydroquinone and benzoquinone are the important compounds of the intermediate products as shown by the analysis of UV spectra and chromatography. The final UV spectra curve indicated that there were little organic compounds containing conjugated structure in the treated wastewater.
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PMID:[Study on the degradation of phenol wastewater using hydroxyl radical produced by plasma and the course by UV spectra]. 1927 10


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