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Results for “Azo Compounds”

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At least 19 recordsLinked to original sources
PubMed1992

Disposition of mesalazine from mesalazine-delivering drugs in patients with inflammatory bowel disease, with and without diarrhoea.

The disposition of mesalazine from the azo compounds sulphasalazine and olsalazine (Dipentum) and from the slow-release mesalazine drugs Pentasa, Asacol, and Salofalk was studied in 20 patients with inflammatory bowel disease. Ten of them had diarrhoea, and 10 had normal stools. On the last 2 days of a 7-day maintenance treatment with each of the study drugs urine and faeces were collected for determination of mesalazine, acetyl-mesalazine, and unsplit azo compound. In patients with and without diarrhoea the urinary and the faecal excretion of acetyl-mesalazine was lowest during treatment with olsalazine. The proportion of acetyl-mesalazine in faeces was highest during treatment with Pentasa in both groups. The presence of diarrhoea was associated with a decrease in the proportion of acetyl-mesalazine in faeces during treatment with all drugs, not significant only for Pentasa. The proportion of unsplit azo compound in faeces increased in the case of diarrhoea to almost 50%. It is concluded that in patients with inflammatory bowel disease diarrhoea substantially influences the disposition from all these drugs except Pentasa.

Adult↗
PubMedDate not supplied

Substrates for microsomal azoreductase. Hammett substituent effects, NMR studies, and response to inhibitors.

In previous studies on azoreduction by microsomal cytochrome P-450, we identified two classes of substrates structurally related to 4-dimethylaminoazobenzene. Both require polar electron-donating groups for binding to enzyme and are differentiated by their structure, their redox potentials, their rates of chemical and enzymic reduction, and the influence on their metabolism of inducing agents, CO and O2. Azo compounds whose reductions are insensitive to CO and O2 (I-substrates) contain electron-donating substituents on either ring. Azo compounds whose reductions are O2- and CO-sensitive (S-substrates) also contain electron-withdrawing groups on the opposite (prime) ring. For all dyes, NMR studies revealed minor differences in the chemical shifts of the protons attached to the phenyl ring substituted with electron-donating substituents (ring A). This is consistent with the narrow range of pKa's (basicity) and KM values for all substrates. However, there are significant differences in the chemical shifts of the aromatic protons of the prime ring (ring B). The difference in chemical shifts is most pronounced for aromatic protons adjacent to the prime ring substituents, showing a clear distinction between I and S substrates. Furthermore, the Hammett sigma substituent constants on the prime ring clearly distinguish between the two classes of dyes. I- and S-substrates have negative and positive sigma Hammett values, respectively. This implies that the mechanism of microsomal azoreduction is critically dependent on the charge and redox potentials of the dyes and is exclusively determined by the nature of the substituents on the prime ring.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

D and C Red No. 9: genotoxic or non-genotoxic carcinogen?

The azo-compound, D and C Red No. 9 was assayed for genotoxicity in vivo using the rat micronucleus test and the rat ex vivo liver UDS assay. Uniformly negative results were obtained in both assays, even though large oral doses were used (2 g/kg). These results suggest that the tumorigenic effects of this compound in rats are mediated through non-genotoxic rather than a genotoxic mechanism. Further experiments using additional end-points such as 32P-post-labelling would further substantiate this conclusion.

Administration, Oral↗
PubMed1977

Chromosome aberrations and sister chromatid exchanges in Chinese hamster cells exposed to various chemicals.

To evaluate its usefulness for detection of mutagenicity and oncogenicity of chemicals, the frequency of chromosome aberrations and sister chromatid exchanges (SCE) was examined in cultured Chinese hamster cells exposed to 33 kinds of chemical agents, including 2 aromatic hydrocarbons, 7 amine derivatives, 3 phenols, 6 carboxylic acid derivatives, 4 azo compounds, 7 heterocyclic compounds, and 4 other types of agents. Among them, 7 chemicals, including 5 known oncogens (N-n-butyl-N-nitrosourethan, N-methyl-N-nitrosourea, beta-propiolacton, methylazoxymethanol acetate, and propane sultone) and 2 non-oncogens (potassium sorbate and sodium benzoate) were inducers of aberrations and/or SCE, although the effective doses for the last two agents were considerably higher. The mutagenic activities estimated by chromosome aberrations were not necessarily the same for a given chemical when estimated by SCE. Slightly to moderately increased rates of SCE or aberrations were noticed among the other 26 chemicals. However, these values were usually without a clear dose relationship.

Amines↗
PubMed1979

Ellipticines as potent inhibitors of microsomes-dependent chemical mutagenesis.

9-Hydroxyellipticine (9-OHE), an inhibitor of microsomal monooxygenase activities has been shown to exert a large or even complete decrease of the mutagenicity, on the Salmonella strains of a great number of compounds (aromatic amines, polycyclic aromatic hydrocarbons, fungal toxins, azo compounds, tobacco smoke condensate). 9-OHE and 9-fluoroellipticine are more potent inhibitors than ellipticine itself. The inhibitions exerted by 9-OHE are not even equalled by 10-fold higher doses of 7,8-benzoflavone (7,8-BF). There is a good correlation between these data and the interaction properties of ellipticines with microsomal cytochromes P-450.

Alkaloids↗
PubMed1977

Properties of enzymes immobilized by the diazotized m-diaminobenzene method.

Some properties of a number of enzymes immobilized by the diazotized m-diaminobenzene (dDAB) method are described. The pH-activity profiles of beta-D-glucosidase, glucoamylase, peroxidase, uricase, and D-glucose oxidase were virtually unchanged on immobilization while those of catalase and dextranase were significantly altered. beta-D-Glucosidase, glucoamylase, and glucose oxidase were found to be more susceptible to denaturation on lyophilization when immobilized than in the native state; however, sorbitol had a marked protective effect in every case examined. Sorbitol was also found to exert a stabilizing effect when lyophilized immobilized preparations were stored. Immobilization marginally improved the stabilities of a number of enzymes to heating at 60 degrees at pH 8.0. The usefulness for continuous reaction of a column of glucoamylase attached to celite was established. The reuse of the solid supports was demonstrated.

Aniline Compounds↗
PubMed1979

Colorimetric acetaminophen determination in pharmaceutical formulations.

Different approaches for the colorimetric determination of acetaminophen, based on its coupling with diazotized o-nitroaniline, are described. Copper(II) chelation with the coupled compound makes the method highly selective. Sensitivity is increased when the acetaminophen assay is carried out indirectly through the determination of the chelate's copper content. Optimum conditions for performing the different approaches are described. The stoichiometric balance for the reactants in the coupled compound and chelate is determined. The degree of dissociation and the instability constant are computed. The rectilinear relationship between the absorbance of the different products and the concentration of acetaminophen allows for its determination in different pharmaceutical formulations. Compared with the official method, the proposed methods give more accurate results.

Acetaminophen↗
PubMed1992

Induction of colitis in rats by 2-2'-azobis(2-amidinopropane) dihydrochloride.

Reactive oxygen metabolites (ROM) may play a role in the pathophysiology of inflammatory bowel disease (IBD) and ischemia-reperfusion-induced intestinal injury. Although there are many reports of intestinal mucosal injury associated with neutrophil-derived ROM, free radicals themselves have not been reported to induce intestinal mucosal injury. We administered intrarectally 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) to rats, an azo compound that generates free radicals in vitro. Acute mucosal injury was assessed histologically by light microscopy and biochemically by myeloperoxidase (MPO) activity. Intrarectal administration of AAPH (60, 90, 150 mg/kg) caused erythema, edema, and histologically verifiable mucosal inflammation. MPO activity was increased 9- to 18-fold above the control level. The levels of thiobarbituric acid (TBA) reactants and sulfhydryls (SH) were significantly (P less than 0.01) increased and decreased, respectively, by 90 mg/kg AAPH. Sulfasalazine, 5-aminosalicylic acid, the LTB4 receptor antagonist SC-41930, and the antioxidant glutathione prevented the inflammation. This model of mucosal inflammation may be useful in evaluating new therapeutic agents for the treatment of IBD.

Amidines↗
PubMed1975

Combined staining of protein-bound sulphydryl groups and DNA in polyacrylamide model systems.

A model system of polyacrylamide films containing protein and DNA has been used to examine the feasibility of combining the dihydroxydinaphthyldisulphide (DDD)-diazonium salt procedure for localizing protein-bound sulphydryl groups with the Feulgen technique for DNA to make possible the direct measurement of both these parameters simultaneously. Optimun conditions for the sulphydryl group reaction require reduction of the protein-containing films in 10% aqueous ammonium sulphide for 3 hr at 50 degree C followed by treatment with a DDD solution at 50 degree C for 4 hr. The final coloured product was developed in a solution of the diazonium salt, Fast Red TR, for 15 min. The azo compound thus produced was completely resistant to hydrochloric acid hydrolysis in the manner of the Feulgen reaction. Calculation of protein-bound sulphydryl groups and DNA from measurements made on doubly-stained films showed excellent agreement between the measured and the expected values.

Acrylamides↗
PubMed1977

An automated continuous-monitoring procedure for the determination of acid phosphatase activity in serum.

The method of Hillmann, in which hydrolysis of alpha-naphthyl phosphate by acid phosphatase is coupled to the formation of an alpha-naphthol-Fast Red TR azo-compound, has been adapted for use with the LKB Produkter AB 8600 reaction rate analyzer. Factors which affect the reproducibility of the method are described and its performance is shown to be superior to that of a manual phenyl-phosphate procedure.

Acid Phosphatase↗
PubMed1977

High-pressure liquid chromatographic analysis of aniline and its metabolites.

A high-pressure liquid chromatographic method has been developed for the determination of nanomole quantities of aniline; its metabolites o- and p-aminophenol, phenylhydroxylamine, nitrosobenzene and nitrobenzene; and azobenzene and azoxybenzene which form non-enzymatically by condensation of reactive metabolites. These compounds were separated by reverse-phase chromatography (mu-Bondapak C18 column) and detected spectrophotometrically. The first four components were eluted using methanol-water (15:85) containing 0.26 M ammonium acetate and 0.015 M nickel acetate as mobile phase. The remaining compounds were eluted with methanol-water (50:50). The stabilities of the metabolites were studied electrochemically and results were used in the development of the chromatographic system.

Aniline Compounds↗