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SYNTHETIC NITROGEN PRODUCTS metal oxide

Lipid oxidation. Lipid oxidation is normally observed as a product discoloration and can be exacerbated with excess levels of bleach. It is catalyzed by metal ions, enzymes, and pigments. Acidic compounds can be used to complex the metal ions. Synthetic antioxidants, such as butylated hydroxtoluene (BHT) and butylated hydroxyanisole (BHA) can be added to the product, but are limited and coming under increased scrutiny due to toxicology concerns. It may be preferable to use natural antioxidants such as lecithin or vitamin E or to dry under vacuum or in an inert (nitrogen, steam) atmosphere. [Pg.1360]

The ability of transition metals to bind and activate organic molecules, and to release the transformed organic product with turnover, forms the basis of the vast catalytic chemistry of transition metal complexes. In addition, metal atoms play a key role at the catalytic center of many enzymes. For example, metalloenzymes play key roles in hydrolysis, oxidation, reduction, electron-transfer chemistry, and many other remarkable processes such as nitrogen fixation. The long-term development of synthetic polymers that perform catalytic chemistry in a manner analogous to enzymes, is a goal of profound interest. [Pg.299]

Enzymatic hydroxylation of a carbon adjacent to an oxygen or nitrogen usually results in dealkylation by spontaneous hydrolysis of the initial hemiacetal or hemiaminal product. These conversions are commonly employed for two synthetic purposes cleavage of methyl ethers and oxidative deamination of amines. The latter is particularly useful in amino-add chemistry. These reactions can be catalyzed by P-450 monooxygenases or by flavin-containing monooxygenases (which are typically metal-free enzymes). As in the previous example, these hydroxylations require two dectrons that must be supplied by NADH or NAD PH, and most synthetic applications have rdied on whole miaobial cells rather than the isolated enzymes (Figure 1.7). [Pg.19]

Metal-catalyzed oxidative addition of nitrogen nucleophiles such as amines and amides to olefins represents a straightforward atom economical approach for the preparation of enamines and enamides, respectively. These aminatimi processes may proceed with Markovnikov or anti-Markovnikov regioselectivity and in the latter case such products can be obtained as either or Z isomers (Scheme 1). Therefore, the ability of the catalyst to control that regiochemistry and stereoselectivity constitutes a chaUenging issue for synthetic chemists. [Pg.57]


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See also in sourсe #XX -- [ Pg.64 , Pg.155 , Pg.357 ]




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Metal nitrogen

Nitrogen oxide production

Nitrogen products

Nitrogeneous production

Production metals

SYNTHETIC NITROGEN PRODUCTS

SYNTHETIC NITROGEN PRODUCTS oxide

Synthetic metals

Synthetic production

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