Sulfide inhibition

Hydrogen sulfide inhibits mitochondrial cytochrome oxidase, resulting in disruption of the electron transport chain and impairing oxidative metabolism. Nervous and cardiac tissues, which have the highest oxygen demand (e.g., brain and heart), are especially sensitive to disruption of oxidative metabolism (Ammann 1986 Hall 1996). 

Anaerobic treatment of high-strength wastewater containing high sulfate poses several unique problems. The conversion of sulfate to sulfide inhibits methanogenesis in anaerobic treatment processes and thus reduces the overall performance efficiency of the system. Treatment of high sulfate pharmaceutical wastewater via an anaerobic baffled reactor coupled... 

In both light and high energy irradiation induced reactions, phenyl-thiol, 2-mercaptomesitylene, and their sulfides inhibit nonchain processes,201202 e.g., the light-induced conversion of benzophenone in 2-propanol to benzopinacol and acetone.99 217 The reaction converts compounds into radicals by removal or addition of hydrogen atoms. The sulfur compounds in rapid hydrogen transfer processes convert the free radicals to stable molecules and may do so repeatedly.46 46... 

Ligands that can coordinate to an active center in an enzyme and prevent coordination by the substrate will tend to inhibit the action of that enzyme. 1 We have seen that azide can occupy the pocket tailored to fit the carbon dioxide molecule. This prevents the latter from approaching the active site. Furthermore, the infrared evidence indicates that the azide ion actually does bind the zinc atom The asymmetric stretching mode of the azide ion is strongly shifted with respect to the free ion absorption. Thus the zinc is inhibited from acting as a Lewis acid towards water with the formation of a coordinated hydroxide ion. Other inhibitors also bind to the metal atom. As little as 4 x I0-6 M cyanide or hydrogen sulfide inhibits the enzymatic activity by 85%. 

Joye, S.B., and Hollibaugh, J.T (1995) Sulfide inhibition of nitrification influences nitrogen regeneration in sediments. Science 270, 623-625. 

Joye, S. B., and HoUibaugh, J. T. (1995). Influence of sulfide inhibition of nitrification on nitrogen... 

Allam, A.I. and Hollis, J.P. (1972) Sulfide inhibition of oxidases in rice roots. Phytopathology, 62, 634-639. 

Gued, L.R., Thomas, R.D., and Green, M., Diallyl sulfide inhibits diethylstilbestiol-induced lipid peroxidation in breast tissue of female ACI rats implications in breast cancer prevention, Oncol Rep., 10,739,2003. 

When the [Fe(TPA)X2] catalysts are reacted with stoichiometric amounts of TBHP in the presence of alkanes, only the alkyl halide is formed and in good yield. 70-80 % of the TBHP oxidizing equivalents is converted into alkyl halide product. The absence of additional products greatly facilitates mechanistic interpretation of the results. For example, the band at 500 nm in [Fe(TPA)Br2] attributed to bromide-to-iron(III) charge transfer decays upon addition of TBHP concomitant with the appearance of the alkyl halide product. NMR studies of the reaction mixture show that the starting complex is converted to a (p-oxo)diferric species during the course of this reaction. Addition of dimethyl sulfide inhibits... 

Other inorganic anions including sulfate, phosphate (Ting and Osmond, 1973 a, b), and sulfide inhibit, the latter presumably by competition with bicarbonate (Avadhani et al., 1971). 

Kinetic Study—Dibenzothiophene Desulfurization. Earlier work at Amoco by Frye and Mosby (8) studied the rate of reaction of single sulfur compounds in light catalytic cycle oil. Conclusions from that study were (1) the reaction kinetics are first order in hydrogen and reactant sulfur (2) hydrogen sulfide inhibits the reaction (3) overall energy of activation is around 28-30 kcal. 

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