Ascorbate salt

Amphotericin B is particularly effective against systemic infections caused by C. albicans and Cryptococcus neoformans. It is poorly absorbed from the gastrointestinal tract and is thus usually administered by intravenous injection under strict medical supervision. Amphotericin B methyl ester (Fig. 5.15C) is water-soluble, unlike amphotericin B itself, and can be administered intravenously as a solution. The two forms have equal antifungal activity but higher peak serum levels are obtained with the ester. Although the ester is claimed to be less toxic, neurological effects have been observed. An ascorbate salt has recently been described which is water-soluble, of similar activity and less toxic. 

Genders, J.D. and Hartsough, D.M. 1999. Electrochemical method for recovery of ascorbic acid from ascorbate salt without formation of waste salt stream. PCT Int. Appl., WO 9,900,178, January, 7th, 1999. 

In many ascorbate salts, the combined effects of metal co-ordination and hydrogen-bonding apparently cause the C-6-OH to adopt a synclinal (or gauche) position with respect to the C-5-OH. 

Craig, J., J. A. Bowers, X. Y. Wang, and P. Seib. 1996. Inhibition of lipid oxidation in meats by inorganic phosphate and ascorbate salts. J. Food Sci. 61 1062-1067. 

Mounanga, T. K., Gdrardin, Ph., Poaty, B. et al. (2008) Synthesis and properties of antioxidant amphiphilic ascorbate salts. Colloid Surf. A, 318, 134-140. 

Trichloroethanoic acid, CCI3COOH. A crystalline solid which rapidly absorbs water vapour m.p. 58°C, b.p. 196-5" C. Manufactured by the action of chlorine on ethanoic acid at 160°C in the presence of red phosphorus, sulphur or iodine. It is decomposed into chloroform and carbon dioxide by boiling water. It is a much stronger acid than either the mono- or the dichloro-acids and has been used to extract alkaloids and ascorbic acid from plant and animal tissues. It is a precipitant for proteins and may be used to test for the presence of albumin in urine. The sodium salt is used as a selective weedkiller. 

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... 

Another group of compounds called oxygen scavengers retard oxidation by reducing the available molecular oxygen. Products in this group are water soluble and include erythorbic acid [89-65-6] C HgO, and its salt sodium erythorbate [6381-77-7] C HgO Na, ascorbyl pahnitate [137-66-6] 22 38 7 ascorbic acid [50-81-7] C HgO, glucose oxidase [9001-37-0] and sulfites (23). 

The reduction of molybdate salts in acidic solutions leads to the formation of the molybdenum blues (9). Reductants include dithionite, staimous ion, hydrazine, and ascorbate. The molybdenum blues are mixed-valence compounds where the blue color presumably arises from the intervalence Mo(V) — Mo(VI) electronic transition. These can be viewed as intermediate members of the class of mixed oxy hydroxides the end members of which are Mo(VI)02 and Mo(V)0(OH)2 [27845-91-6]. MoO and Mo(VI) solutions have been used as effective detectors of reductants because formation of the blue color can be monitored spectrophotometrically. The nonprotonic oxides of average oxidation state between V and VI are the molybdenum bronzes, known for their metallic luster and used in the formulation of bronze paints (see Paint). 

It is shown that both Sb(III) and Bi(III) can speed reduction of 12-molybdophosphate (12-MPC) to the corresponding heteropoly blue (12-MPB) by ascorbic acid (AA). It is found that mixed polyoxometalates can be formed in solution which reduce considerably more rapidly than 12-MPC. Complete formation of mixed POM is observed only if significant excess of Me(III) ions is used in the reaction. POM responsible for blue color was synthesized by selective extraction. Chemical analysis of tetrabutyl-ammonium salt is in accordance with formula of (TBAl PMeflllfMo O j (Me = Sb, Bi). IR spectmm of mixed POM is identical to 12-MPC. 

Until recent years the only syntheses of 3-hydroxy quinoline involved multistep processes, the last step of which consisted of the conversion of 3-aminoquinoline to 3-hydroxyquinoline via the diazonium salt. " Small quantities of quinoline have been oxidized to 3-hydroxyquinoline in low yields by using oxygen in the presence of ascorbic acid, ethylenediaminetetraacetic acid, ferrous sulfate, and i)hosi)halc buffer. The decarboxylation of 3-hydroxycinchoninic, acid in boiling nitrobenzene has been re-... 

Organic acids convert the blue mesomerically stabilized phenolate anion to the red undissociated acid. Reductones (e.g. ascorbic acid) reduce the reagent to a colorless salt. 

Numerous new salts and additive compounds of cinchona alkaloids, and especially of quinine, have been described, of which only a few can be mentioned as examples quinine additive compounds with sulph-anilamide, t quinine salts of (+) and (—)-pantothenic acid, °( > quinine sulphamate and disulphamate, °( organo-mercury compounds of quinine and cinchonine such as quinine-monomercuric chloride. Various salts and combinations of quinine have also been protected by patent, e.g., ascorbates and nicotinates. 

Octasodium salt of octa-4,5-dicarboxyphthalocyanin cobalt(II) combined with ascorbic acid (teraphthal) as a new drug for binary catalytic therapy of malignant tumors 98MI57. 

Various initiation strategies and surfactant/cosurfactant systems have been used. Early work involved in situ alkoxyamine formation with either oil soluble (BPO) or water soluble initiators (persulfate) and traditional surfactant and hydrophobic cosurfactants. Later work established that preformed polymer could perform the role of the cosurfactant and surfactant-free systems with persulfate initiation were also developed, l90 222,2i3 Oil soluble (PS capped with TEMPO,221 111,224 PBA capped with 89) and water soluble alkoxyamines (110, sodium salt""4) have also been used as initiators. Addition of ascorbic acid, which reduces the nitroxide which exits the particles to the corresponding hydroxylamine, gave enhanced rates and improved conversions in miniemulsion polymerization with TEMPO.225 Ascorbic acid is localized in the aqueous phase by solubility. 

Garcia-Viguera, C. and Bridle, R, Influence of structure on colour stability of anthocyanins and flavylium salts with ascorbic acid, Food Chem., 64, 21, 1999. 

Rowley, D.A. and HaUiwell, B. (1983a). Formation of hydroxyl radicals from hydrogen peroxide and iron salts by superoxide-and ascorbate-dependent mechanisms relevance to the pathology of rheumatoid disease. Clin. Sci. 64, 649-654. 

Rowley, D.A. and Halliwell, B. (1983b). Superoxide-dependent and ascorbate-dependent formation of hydroxyl radicals in the presence of copper salts a physiologically significant reaction. Arch. Biochem. Biophys. 225, 279-284. 

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