L-Ascorbic Acid Vitamin C

Asbolite, 7 2091 Ascharite, 4 1331 Ascorbate free radical, 25 769 Ascorbic acid, 12 60, 61 25 745-781, 804-805. See also L-Ascorbic acid Vitamin C... 

Vitamin C Is the Synthetic Vitamin as Good as the Natural One A claim put forth by some purveyors of health foods is that vitamins obtained from natural sources are more healthful than those obtained by chemical synthesis. For example, pure L-ascorbic acid (vitamin C) extracted from rose hips is better than pure L-ascorbic acid manufactured in a chemical plant. Are the vitamins from the two sources different Can the body distinguish a vitamin s source ... 

The reaction of L-sorbose with acetone, a step in the synthesis of L-ascorbic acid (vitamin C), takes place in acetone solution [Eq. (41)] (361). 

Banwell M, Blakey S, Harfoot G, Longmore R (1998) First Synthesis of L-Ascorbic Acid (Vitamin C) from a Non-Carbohydrate Source. J Chem Soc Perkin Trans 1 3141... 

PMMA and Topas microchips with EC detection can be used for determination of vitamins such as L-ascorbic acid (vitamin C) and other compounds such as p-aminophenol and hydrogen peroxide. 

Keto-L-Gulonic acid (2-KLG) is the precursor for Vitamin C (L-Ascorbic acid). Vitamin C is used on a large scale as an antioxidant in food, animal feed, beverages, pharmaceutical formulations, and cosmetic applications. About one half of the vitamin C is used in vitamin supplements and multivitamin preparations, one quarter in food additives, 15 percent in beverages, and 10 percent in animal feed. When ascorbic acid is used in... 

Hydrogenation of L-ascorbic acid (vitamin C) takes place stereoselctively to give l-gluco-1,4-lactone in high yield over Pd-C,156 or better, over Rh-C in water at temperature below 45°C and 0.38 MPa H2 (eq. 3.29).157 It is noted that hydrogen adds preferentially from the least hindered side opposite the side chain. 

L-Ascorbic acid (vitamin C, ASA) is produced on a scale of 80 kt a-1 worldwide it is used in food supplements, pharmaceutical preparations, cosmetics, as an antioxidant in food processing and a farm animals feed supplement [145]. It is synthesized in vivo by plants and many animals, but not by primates, including Man, or microbes. 

VITAMIN C (L-ascorbic acid) Vitamin C plays an important role as a redox-catalyst in metabolism in teeth, bone, cartilage and parenchyma-tissue. Vitamin C occurs in several fruits such as an rose hips (Cynosbatifructus), Black currant. Sallow-thorn (Hippophae rhamnoides), Citrus-fruits, Paprika, Potato, Cabbage, and Parsley. 

Ascorbic Acid, the Natural Antioxidant. L-Ascorbic acid, vitamin C, is a biological antioxidant, arguably the water-soluble one to complement the... 

Lactones are commonly found in nature. For example, L-ascorbic acid (vitamin C) is a lactone derivative of D-glucuronic acid (Special Interest Box 7.1). 

Parenteral formulations often contain excipients considered to be chemically stable and inert however, all excipients in a formulation may influence the photochemical stability of the product. Dextrose and sodium chloride are used to adjust tonicity in the majority of parenteral formulations. Sodium chloride can affect photochemical processes by influencing solvation of the photoreactive molecules (see Section 14.2.3). The ionic strength is reported to affect the photochemical decomposition rate of minoxidil until a saturation level is reached (Chinnian and Asker, 1996). The photostability of L-ascorbic acid (vitamin C) in aqueous solution is enhanced in the presence of dextrose, probably caused by the scavenging effect of the excipient on hydroxyl radicals mediated by the photolysis of ascorbic acid sucrose, sorbitol, and mannitol have the same effect (Ho et al., 1994). Monosaccharides (dextrose, glucose, maltose, and lactose), disaccharides (sucrose and trehalose), and polyhydric alcohols (inositol, mannitol, and sorbitol) are examples of commonly used lyo-additives in parenterals. These excipients may also affect photochemical stability of the products after reconstitution. 

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