- Method of oxidization using nitric acid
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A controlled nitric acid process employing oxygen and nitric acid as co-oxidants is used to oxidize organic compounds subject to nitric acid oxidation, to their corresponding carboxylic acids. Oxidation of some carbohydrates by this process can produce one or more of their corresponding acid forms. The process is carried out at moderate temperatures, typically in the range of 20° C. to 45° C. in a closed reactor, with oxygen gas being introduced into the reaction chamber as needed in order to sustain the reaction. Computer controlled reactors allow for careful and reproducible control of reaction parameters. Nitric acid can be recovered by a distillation/evaporation process, or by diffusion dialysis, the aqueous solution made basic with inorganic hydroxide, and the residual inorganic nitrate removed using a filtration (nanofiltration) device. The method eliminates issues of thermal control of the oxidation, release of nitrogen into the atmosphere, and post-reaction difficulties in the removal of nitric acid and inorganic nitrates.
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Page/Page column 6
(2008/06/13)
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- Facile nitroxide-mediated oxidations of D-glucose to D-glucaric acid
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The oxidation of D-(+)-glucose to D-glucaric acid using the TEMPO-like nitroxide oxidation catalyst, 4-acetamido-2,2,6,6-tetramethyl-1-piperidinyloxy (4-acetamido-TEMPO) was carried out using several oxidizing agents and co-catalyst. The pH and temperature of the reactions were closely monitored to decrease degradations during the oxidation, and several isolation methods were explored.
- Merbouh, Nabyl,Francois Thaburet, Jean,Ibert, Mathias,Marsais, Francis,Bobbitt, James M
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- Molecular mechanism of the control of nyctinastic leaf-movement in Lespedeza cuneata G. Don
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The nyctinastic leaf-movement of plants is controlled by an endogenous biological clock. In a nyctinastic plant, Lespedeza cuneata G. Don, this movement is controlled by the balance of the concentration between the leaf- dosing and -opening substance. Quantitative HPLC analysis revealed that the change in the concentration of this leaf-opening substance is inversed through a day, and the deactivation of this substance is performed by a glucosidase whose activity is controlled by a biological clock. The leaf- movement of nyctinastic plants is caused by the balance of two leaf-movement factors which is controlled by the enzymatic transformation.
- Ohnuki, Takashi,Ueda, Minoru,Yamamura, Shosuke
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p. 12173 - 12184
(2007/10/03)
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