Hydrogen peroxide accumulation effect

Grufferty, R. C. and Condon, S. 1983. Effect of fermentation sugar on hydrogen peroxide accumulation by Streptococcus lactis CIO. J. Dairy Res. 50, 481-489. 

Leoncini, G., and Poggi, M. 1996. Effects of methylglyoxal on platelet hydrogen peroxide accumulation, aggregation and release reaction. Cell Biochem Funct 14 89-95. 

Figure 2. Effect of pH on hydrogen peroxide accumulation. Total HOAc/OAc concentration is 0.015 M.

The decomposition of liquid water and the following reactions are the results of a typical chemical effect. In this case, however, overall water splitting does not occur because oxygen is not obtained but hydrogen and hydrogen peroxide are. On the other hand, it is impossible to decompose water by photochemical reaction under illumination with a xenon lamp. Although it is possible to decompose water by photocatalytic reaction using a desirable photocatalyst and photoirradiation, it is difficult to decompose in practice because of rapid backward reaction, the formation and accumulation of intermediates onto the surface of photocatalyst,10) and other reasons. 

Ferric ion catalyzes the formation of the hydroperoxyl radical, according to Eq. (35) such a radical appears to constitute the oxidant in the Ruff method of degrading aldonic acids to the next lower aldoses. A number of examples of the use of this reagent in the laboratory are given in a review article by Moody.108 The hydroperoxyl radical, which is not so effective an oxidant as the hydroxyl radical, does not attack aliphatic alcohols accordingly, a substantial yield (about 50%) of the aldose is obtained from the higher aldonic acid. In the presence of an excess of hydrogen peroxide, however, the accumulation of ferrous ions in solution catalyzes the production of hydroxyl radicals and lowers the yield of aldose [see Eq. (36)]. 

The results from the publications mentioned are of interest because they can help in the creation of effective catalytic systems containing porphyrins, which combine functions typical of multienzyme systems. The task in hand is the possible synthesis of bifunctional catalysts based on metalloporphyrin systems, when with the help of manganese porphyrins, for example, or SOD mimic, hydrogen peroxide is accumulated in the system. Afterwards, the accumulated hydrogen peroxide is used in oxidation reactions of various substrates with iron porphyrin components of the catalyst. 

The accumulated ACC appears to be transported to the shoot, where it induces more synthesis of ACC which is converted to ethylene and cyanide. Treatment of isolated shoots with ACC via the vascular system stimulated ACC synthase activity and ethylene and cyanide production [7,37,49,51]. Cyanide was formed as a coproduct of ethylene in the oxidation of ACC, catalyzed by ACC oxidase [14,52]. While quinclorac-induced increases of ABA and hydrogen peroxide are not enough to elicit herbicidal effects [7], cyanide levels in the grass shoot tissue accumulated according to the herbicide concentration and application time and closely correlated with phytotoxicity... 

Imidazoles (ketoconazole, miconazole, fenticonazole, clotrimazole, isoconazole, tioconazole) interfere with fungal oxidative enzymes to cause lethal accumulation of hydrogen peroxide they also reduce the formation of ergosterol, an important constituent of the fungal cell wall which thus becomes permeable to intracellular constituents. Lack of selectivity in these actions results in important adverse effects. 

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