Ascorbic acid vitamine

Sorbitol is manufactured by the reduction of glucose in aqueous solution using hydrogen with a nickel catalyst. It is used in the manufacture of ascorbic acid (vitamin C), various surface active agents, foodstuffs, pharmaceuticals, cosmetics, dentifrices, adhesives, polyurethane foams, etc. 

Uronic acids are biosynthetic intermediates m various metabolic processes ascorbic acid (vitamin C) for example is biosynthesized by way of glucuronic acid Many metabolic waste products are excreted m the urine as their glucuronate salts... 

See also Ascorbic acid.) [VITAMINS - ASCORBIC ACID] (Vol 25)... 

Woodward-Eschenmoser method, 4, 431-440 neo-Vitamin B,2, 4, 421 Vitamin C — see Ascorbic acid Vitamin E — see a-Tocopherol Vitamin K epoxide, 7, 119 synthesis, 1, 439 Vitamins heterocyclic... 

Thus, it is uncertain to what extent the apparent protective effects of fruit and vegetable consumption on risk of stomach cancer can be attributable to their phytoestrogen content. This appears not to have been studied directly, and other constituents such as ascorbic acid (vitamin C), a-tocopherol (vitamin E) and /1-carotene may be potentially protective. 

FIGURE 6.17 Hydroxylation of proUne residnes is catalyzed by prolyl hydroxylase. The reaction requires -ketoglntarate and ascorbic acid (vitamin C). 

FIGURE 18.30 The physiological effects of ascorbic acid (vitamin C) are the result of its action as a reducing agent. A two-electron oxidation of ascorbic acid yields dehy-droascorbic acid. 

The juice of many fruits and particularly those of the citrus family contain appreciable quantities of ascorbic acid (vitamin C). It is not possible to examine... 

Ascorbic acid—vitamin C—is an essential nutrient that the human body cannot manufacture from other compounds. It is needed for the formation of collagen, the protein that makes up connective tissue, and is essential to muscles, bones, cartilage, and blood vessels. It is a strong antioxidant, preventing damage from oxygen free radicals. 

Potassium sorbate is added to inhibit yeasts and fungi. Ascorbic acid (vitamin C) is used as an antioxidant. 

Eberlein-Konig B, Placzek M, Pryzbilla B (1998) Protective effect against sunburn of combined systemic ascorbic acid (vitamin C) and d-alpha-tocopherol (vitamin E). J Am Acad Dermatol 38 45-48... 

Commercial green tea leaves contain ascorbic acid (vitamin C) about 280 mg per 100 g dried leaves. Vitamin E in tea leaves is around 24-80 mg/lOOg dry weight but, because of its lipophilicity, solubility is low in tea infusions. The content of B vitamins in tea is around 8-15 mg/lOOg (Cheng and Chen 1994). 

Table 4.9 Summary of reaction metrics and synthesis tree parameters for ascorbic acid (vitamin C) synthesis plans ranked according to overall kernel (maximum) RME .

Ascorbic acid (vitamin C) depletion is the most consistent evidence of compromised antioxidant status in diabetes with reports of reduced levels and altered metabolic turnover in several tissues in experimentally induced diabetes in animals (Rikans, 1981 Yew, 1983 McLennan et al., 1988) and in patients with diabetes (Som et al., 1981 Jennings et al., 1987 Sinclair et al., 1991). 

Ascorbic acid (vitamin C) is one of the body s endogenous water-soluble antioxidants. Modifications on the ascorbic acid structure have led to some very interesting compounds, such as a novel series of 3-O-alkyl ascorbic-acid derivatives. They have been found to be inhibitors of lipid peroxidation (Nihro etal., 1991). This antioxidant activity is directly related to the lipophilicity of the alkyl chain, su esting that the lipid chain may anchor the antioxidant portion of the molecule in the membrane. 

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