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Sample records for bromamines

  1. Mechanistic chemistry of oxidation of balsalazide with acidic chloramine-T and bromamine-T: A comparative spectrophotometric kinetic study

    Indian Academy of Sciences (India)

    Puttaswamy; S Dakshayani

    2014-11-01

    Balsalazide (BSZ) belongs to a class of non-steroidal anti-inflammatory drugs. Kinetics and mechanism of oxidation of BSZ with sodium N-halo-p-toluenesulfonamides viz., chloramine-T(CAT) and bromamine-T(BAT) in HClO4 medium have been spectrophotometrically investigated (max =357nm) at 303 K. Under comparable experimental conditions, reactions with both the oxidants follow a first-order dependence of rate on [BSZ] and fractional-order dependence on each [oxidant] and [HClO4]. Activation parameters and reaction constants have been computed. 2-hydroxy-5-nitroso-benzoic acid and 3-(4-nitroso-benzoylamino)-propionic acid are identified as the oxidation products of BSZ with both CAT and BAT. The rate of oxidation of BSZ is about five-fold faster with BAT than with CAT. Plausible mechanism and related rate law have been deduced for the observed kinetics.

  2. Kinetics and Mechanistic Studies on Oxidation of Levocarnitine by Bromamine-T in HCl Medium Catalyzed by Ru(III

    Directory of Open Access Journals (Sweden)

    R. Ramachandrappa

    2013-01-01

    Full Text Available A kinetic study on RuCl3-catalysed oxidation of levocarnitine (LC by sodium N-bromo-p-toluenesulphonamide or bromamine-T (BAT has been carried out in HCl medium at 303 K. The reaction rate shows a first order dependence on [BAT]0 and fractional order with respect to both [LC]0 and [H+]. Addition of the reaction product, p-toluenesulphonamide, retards the rate. The addition of RuCl3 and chloride ions to the reaction mixture shows an increase in the rate of the reaction. The dielectric effect is positive. The variation of ionic strength of the medium has no significant effect on the rate of the reaction. The reaction fails to initiate polymerization of acrylamide. Michaelis-Menten type of kinetics has been proposed. Thermodynamic parameters have been computed from Arrhenius plot by studying the reaction at different temperatures. The reaction stoichiometry and oxidation products were identified. Based on the experimental observations a suitable mechanism was proposed and rate law deduced.

  3. ZnO/TiO2改性催化剂在阳光照射下对溴氨酸水溶液的催化降解%Photocatalytic Degradation of Bromamine Acid by Modified ZnO/TiO2 Photocatalyst under Sunlight

    Institute of Scientific and Technical Information of China (English)

    徐晓娟; 费学宁; 李莹

    2008-01-01

    采用溶胶-凝胶法制备了具有可见光响应的ZnO/TiO2催化剂.考察了煅烧温度、煅烧时间、ZnO掺杂量对ZnO/TiO2催化剂性能的影响及阳光下不同紫外线强度对znO/TiO2催化剂降解溴氨酸水溶液的影响.结果表明:当煅烧温度为400℃,煅烧时间为2h,znO掺杂比为1%时,催化剂性能较佳;紫外线指数为5,光照5h时,溴氨酸水溶液的褪色率达到100%,在太阳光直射下3h后,溴氨酸水溶液的褪色率为97.73%,TOC去除率为82.88%.

  4. Properties of a novel acid dye 1-amino-4-[(6-nitro-2-benzothiazolyl)amino]-9,10-anthraquinone-2-sulfonic acid with anti-UV capability

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel acid dye acid was synthesized by the condensation reaction between bromamine acid and 2-amino-6-nitrobenzothiazole and its anti-UV protection properties were evaluated.The results showed that silk dyed with this dye had very good ultraviolet radiation protection capability and excellent dyeing performance.The UV-absorption mechanism of this dye was also discussed.

  5. Kinetic method for assaying the halogenating activity of myeloperoxidase based on reaction of celestine blue B with taurine halogenamines.

    Science.gov (United States)

    Sokolov, A V; Kostevich, V A; Kozlov, S O; Donskyi, I S; Vlasova, I I; Rudenko, A O; Zakharova, E T; Vasilyev, V B; Panasenko, O M

    2015-06-01

    Myeloperoxidase (MPO) is a challenging molecular target which, if put under control, may allow regulating the development of inflammatory reactions associated with oxidative/halogenative stress. In this paper, a new kinetic method for assaying the halogenating activity of MPO is described. The method is based on measuring the rate of iodide-catalyzed oxidation of celestine blue B (CB) by oxygen and taurine N-chloramine (bromamine). The latter is produced in a reaction of taurine with HOCl (HOBr). CB is not a substrate for the peroxidase activity of MPO and does not react with hydrogen peroxide and superoxide anion radical. Taurine N-chloramine (bromamine) reacts with CB in molar ratio of 1:2. Using the new method, we studied the dependence of MPO activity on concentration of substrates and inhibitors. The specificity of MPO inhibition by non-proteolyzed ceruloplasmin is characterized. The inhibition of taurine N-chloramine production by neutrophils and HL-60 cells in the presence of MPO-affecting substances is demonstrated. The new method allows determining the kinetic parameters of MPO halogenating activity and studying its inhibition by various substances, as well as screening for potential inhibitors of the enzyme.

  6. Adsorption of Anthraquinone Dyes from Aqueous Solutions by Penicillium Terrestre

    Institute of Scientific and Technical Information of China (English)

    XIN Bao-ping; LIU Xiao-mei

    2006-01-01

    Penicillium terrestre was used for removing four anthraquinone dyes from aqueous solution. The experiments were performed in Erlenmeyer flasks and spore suspension was used for inoculation. The results show that the mechanism of dye removal by penicillium terrestre is biosorption and the growing pellets exhibit higher adsorptive capacity than the resting or dead ones. The maximum removals of disperse blue 2BLN, reactive brilliant blue KN-R, acid anthraquinone blue and bromamine acid at the concentration of 120 mg/L by biosorption of growing pellets are 100 %, 100 %, 96 % and 91%, respectively. The 100.0 % and 91.4 % KN-R removals are achieved respectively at the much higher concentration of 250 and 400 mg/L. 2.5 g/L glucose is sufficient for 100% KN-R removal by growing pellets. Salinity (NaC1) increase from 0 to 2% (W/V) moderately accelerates both mycelium growth and KN-R removal.

  7. Increased concentrations of breath haloamines are not detectable in airways inflammation using SIFT-MS.

    Science.gov (United States)

    Storer, Malina K; Dummer, Jack D; Cook, Julie; McEwan, Murray; Epton, Michael J

    2011-09-01

    The haloamines, including the chloramines (H(2)NCl, HNCl(2)) and bromamine (H(2)NBr), are diffusible gases that are likely to be produced during inflammation and so may be present as markers of lung inflammation on breath. Although haloamines are quite reactive, it is possible to measure these compounds in humid samples using SIFT-MS. Until recently the quantification of haloamines in breath suffered from interference from other common breath compounds. This was overcome by heating the flow tube which removed major water cluster product ions. Despite the improvements to the method, previous attempts to measure the haloamines in breath samples from normal volunteers had found no evidence to support their presence. Since it is proposed that the haloamines may be present in higher concentrations during airways inflammation we have attempted to detect the compounds in the exhaled breath of patients with airways inflammatory conditions. On-line and off-line breath samples were analyzed; however, there was no discernable change to any of product ions when compared to ambient air or normal subjects. This suggests that despite sensitivity in the mid part per trillion range haloamines are not significantly raised in airways inflammation.

  8. Kinetics of oxidation of acidic amino acids by sodium N-bromobenzenesulphonamide in acid medium: A mechanistic approach

    Indian Academy of Sciences (India)

    Puttaswamy; Nirmala Vaz

    2001-08-01

    Kinetics of oxidation of acidic amino acids (glutamic acid (Glu) and aspartic acid (Asp)) by sodium N-bromobenzenesulphonamide (bromamine-B or BAB) has been carried out in aqueous HClO4 medium at 30°C. The rate shows firstorder dependence each on [BAB]o and [amino acid]o and inverse first-order on [H+]. At [H+] > 0 60 mol dm-3, the rate levelled off indicating zero-order dependence on [H+] and, under these conditions, the rate has fractional order dependence on [amino acid]. Succinic and malonic acids have been identified as the products. Variation of ionic strength and addition of the reaction product benzenesulphonamide or halide ions had no significant effect on the reaction rate. There is positive effect of dielectric constant of the solvent. Proton inventory studies in H2O-D2O mixtures showed the involvement of a single exchangeable proton of the OH- ion in the transition state. Kinetic investigations have revealed that the order of reactivity is Asp > Glu. The rate laws proposed and derived in agreement with experimental results are discussed.