52316-57-1Relevant articles and documents
Is there a role of taurine bromamine in inflammation? Interactive effects with nitrite and hydrogen peroxide
Marcinkiewicz,Mak,Bobek,Biedron,Bialecka,Koprowski,Kontny,Maslinski
, p. 42 - 49 (2005)
Objective and Design: The myeloperoxidase system of neutrophils generates chlorinating and brominating oxidants in vivo. The major haloamines of the system are taurine chloramine (TauCl) and taurine bromamine (TauBr). It has been demonstrated in vitro that TauCl exerts both antiinflammatory and anti-bacterial properties. Much less is known about TauBr. The present study was conducted to compare bactericidal and immunoregulatory capacity of TauBr with that of the major chlorinating oxidants: HOCl and TauCl. Moreover, the effect of nitrites and H2O2 on TauBr activity was investigated. Materials: TauBr was prepared by reaction of HOBr with taurine. The reaction was monitored by UV absorption spectra. Methods: Bactericidal activity of TauBr, TauCl and HOCl was tested by incubation of E. coli with the compounds and determined by the pour-plate method. To test the anti-inflammatory activity the compounds were incubated with LPS and IFN-γ stimulated murine peritoneal macrophages. The production of following mediators was measured: nitrites by Griess reaction; TNF-α, IL-6, IL-10, IL-12p40 using capture ELISA. In some experiments the compounds were incubated with either nitrites or H 2O2. Results: In our experimental set-up TauBr and HOCl exerted strong bactericidal effects on E. coli (MBC = 110 μM and 8 μM, respectively), while TauCl (2O2 completely abolished the biological activities of TauBr but not those of TauCl. Nitrites did not affect any activity of TauBr or TauCl while they diminished the HOCl- mediated bacterial killing. Conclusion: TauBr, despite very low concentration of Br- in body fluids, may support TauCl and HOCl in the regulation of inflammatory response and in killing of bacteria by neutrophils. However, TauBr activity in vivo will depend on the presence of H2O2 and possible other mediators of inflammation which can compete with target molecules for TauBr. Birkhaeuser Verlag, Basel, 2005.
Complex kinetics in the reaction of taurine with aqueous bromine and acidic bromate: A possible cytoprotective role against hypobromous acid
Simoyi, Reuben H.,Streete, Kevin,Mundoma, Claudius,Olojo, Rotimi
, p. 136 - 143 (2007/10/03)
The most abundant aminoacid in the human body, 2-aminoethanesulphonic acid (H2NCH2CH2SO3H), is surprisingly stable and reacts exceedingly slowly even with the most powerful oxidizing agents like acidic bromate. Oxidation occurs only on the nitrogen centre to give the corresponding N-derivatives. No activity is observed at the sulphonic acid group and no cleavage of the C-S bond is observed. The stoichiometry of the oxidation of 2-aminoethanesulphonic acid by bromate is complex, yielding a mixture of monobromo- and dibromotaurines, oximes as well as the corresponding dimeric azo-compounds. In the presence of added bromide, the stoichiometry of the reaction is: 2BrO3- + 3H2NCH 2CH2SO3H + 6H+ + 4Br- → 3Br2NCH2CH2SO3H + 6H 2O. Monobromotaurine is formed as an intermediate product before formation of the dibromotaurine. Aqueous bromine reacts quantitatively with 2-aminomethanesulphonic acid according to the stoichiometry: H 2NCH2CH2SO3H + 2Br2 → Br2NCH2CH2SO3H + 2Br - + 2H+. This reaction is strongly inhibited by acid due to the deactivation of the amino group to electrophilic attack by protonation. The formation of N-bromotaurines is suggested as a possible mechanism by which taurine can moderate the oxidative toxicity of bromine and hypobromous acid in the slightly basic physiological environments.
