Application Vitamins

Vitamins are organic compounds needed in small amounts for normal cell function. Our 

Whether a vitamin is fat soluble (it dissolves in organic media) or water soluble can be determined by applying the solubility principles discussed in Section 3.4C. Vitamins A and C illustrate the differences between fat-soluble and water-soluble vitamins. 

The name vitamin was first used in 1912 by the Polish chemist Casimir Funk, who called them vitamines, because he thought that they all contained an amine functional group. Later the word was shortened to vitamin, because some are amines but others, like vitamins A and C, are not. 

Ingesting a moderate excess of vitamin A doesn t cause any harm, but a large excess causes headaches, loss of appetite, and even death. Early Arctic explorers who ate polar bear livers, which contain an unusually large amount of vitamin A, are thought to have died from consuming too much vitamin A. 

Vitamin A is synthesized from p-carotene, the orange pigment in carrots. 

Problem 3.12 Label the hydrophobic and hydrophilic portions of each molecule  

Vitamin A contains 20 carbons and a single OH group, making it water insoluble. Because it is organic, it is soluble in any organic medium. To understand the consequenc es of these solubility characteristics, we must learn about the chemical environment of the body. 

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Application Vitamin supplement Insect repellent Mouthwash Adhesive... 

Alternative AOs for providing melt-processing stability include natural or s)m-thetic vitamin E (as oi-tocopherol, its active form). As a safe, biocompatible alternative for food and health product packaging and human-contart applications, vitamin E is a fast-acting, hindered-phenolic AO that stabilizes via a complicated reaction mechanism analogous to its reactions in a living body, ft is more expensive than other phenohc AOs, though it can be used in lower concentrations (0.025% or lower) [1-1, 3-5]. 

Overview. Polychlorinated Biphenyls. Polycyclic Aromatic Hydrocarbons Determination. Polymers Natural Rubber Synthetic Polyurethanes. Quality Assurance Quality Control Instrument Calibration Interlaboratory Studies Reference Materials Production of Reference Materials Method Validation Accreditation Clinical Applications Water Applications. Sample Handling Comminution of Samples Sample Preservation Automated Sample Preparation Robotics. Sampling Theory Practice. Solvents. Supercritical Fluid Chromatography Overview Applications. Vitamins Overview Fat-Soluble. 

See also Bioassays Overview Microbial Tests Bioautography. Blood and Plasma. Fluorescence Clinical and Drug Applications Food Applications. Food and Nutritional Analysis Dairy Products. Gas Chromatography Mass Spectrometry. Immunoassays, Techniques Enzyme Immunoassays. Liquid Chromatography Normal Phase Reversed Phase Food Applications. Microbiological Techniques. Radiochemical Methods Food and Environmental Applications. Vitamins Fat-Soluble. 

The technique of hydrodynamic modulation voltammetry (HMV), in which the rate of stirring is pulsed between high and low values, is demonstrated in this experiment. The application of HMV for the quantitative analysis of ascorbic acid in vitamin C tablets using the method of standard additions also is outlined. 

Examples of the application of ion-exchange chromatography to the analysis of (a) inorganic anions, (b) inorganic cations, (c) antifreeze, and (d) vitamins. (Chromatograms courtesy of Alltech Associates, Inc. Deerfield, IL). 

Antistatic coatings Antistatic finishes Antistatic yarns Antistatin D Antisterility vitamin Antistick agents Antistick applications Anti-Stokes lines... 

K. Mbnzel, ia. C. Bauemfeiud, ed.. Carotenoids as Colorants and Vitamin A Precursors, Technological and Nutritional Applications, Academic Press, Inc., New York, 1981, pp. 781-813. 

A. W. Norman, R. Bouillon, M. Thomasset, eds.. Vitamin D. A Pluripotent Steroid Hormone Structural Studies, Molecular Endocrinology and Clinical Applications. Proceedings of the Ninth Workshop on Vitamin D, Orlando, Florida, May 1994, Walter de Gmyter, Berlin, 1994, p. 89. 

H. F. DeLuca and H. K. Schnoes, ia A. W. Norman and co-eds.. Vitamin D Recent Basic Mdvances and Their Clinical Application, Walter de Gmyter, Eknsford, N.Y., 1979. 

Ascorbic acid commonly known as vitamin C, is one of the most important water soluble vitamins. Ascorbic acid is involved in many biological processes and it is an essential compound in the human diet [1]. The determination of ascorbic acid has gained increase significance in pharmaceutic, clinical, and food applications. So far, different methods have been developed for determination of ascorbic acid [2, 3]. 

In the post-World War II years, synthesis attained a different level of sophistication partly as a result of the confluence of five stimuli (1) the formulation of detailed electronic mechanisms for the fundamental organic reactions, (2) the introduction of conformational analysis of organic structures and transition states based on stereochemical principles, (3) the development of spectroscopic and other physical methods for structural analysis, (4) the use of chromatographic methods of analysis and separation, and (5) the discovery and application of new selective chemical reagents. As a result, the period 1945 to 1960 encompassed the synthesis of such complex molecules as vitamin A (O. Isler, 1949), cortisone (R. Woodward, R. Robinson, 1951), strychnine (R. Woodward, 1954), cedrol (G. Stork, 1955), morphine (M. Gates, 1956), reserpine (R. Woodward, 1956), penicillin V (J. Sheehan, 1957), colchicine (A. Eschenmoser, 1959), and chlorophyll (R. Woodward, 1960) (page 5). ... 

An important application of the allylic bromination-dehydrobromination approach is the formation of the A -diene system e.g. 110) in vitamin D synthesis. Dehydrobromination of the A -7-bromo system in the presence of mercuric chloride gives a high yield of A -diene. ... 

When the enamine is in conjugation with a carbonyl function, as in a-aminomethylene aldehydes (528,529), ketones (530), or esters (531), a Michael addition is found in vinylogous analogy to the reactions of amides. An application to syntheses in the vitamin A series employed a vinyl lithium compound (532). 

Selected applications of coupled SEE-SEC consider the analysis of tocopherols in plants and oil by-products (65) or the analysis of lipid-soluble vitamins (66) by using a dynamic on-line SEE-SEC coupling, integrated in the SE chromatograph, based on the use of micropacked columns. 

This IS used for synthesis of porphobilinogen fEq 10 24 Porphobilinogen is the key building block in the biosynthesis of pigments of life such as porphyrins, heme, and vitamin Interestmg application of porphobdiogen to synthesis of immunocomponents for the measurement of lead fPb by fluorescence polarizadon Immunoassay has been reported "... 

Important organic applications are to the determination of quinine and the vitamins riboflavin (vitamin B2) and thiamine (vitamin Bj). Riboflavin fluoresces in aqueous solution thiamine must first be oxidised with alkaline hexacyanoferrate(III) solution to thiochrome, which gives a blue fluorescence in butanol solution. Under standard conditions, the net fluorescence of the thiochrome produced by oxidation of the vitamin Bj is directly proportional to its concentration over a given range. The fluorescence can be measured either by reference to a standard quinine solution in a null-point instrument or directly in a spectrofluorimeter.27... 

Application of vitamin K-antagonistic anticoagulants like warfarin gave no clearcut results concerning bone density or a changed risk for bone fractures. 

This procedure illustrates a broadly applicable method which is essentially that of Roth, Dubs, Gotschi, and Eschenmoser,2 for the synthesis of enolizable /1-dicarbonyl compounds. Although there are various methods for the preparation of /3-dicarbonyl systems,3 the scheme of sulfide contraction widens the spectrum of available methods. The procedure can also be utilized in the synthesis of aza and diaza analogs of /3-dicarbonyl systems. Eschenmoser2 has utilized the method to produce vinylogous amides and amidines in connection with the total synthesis of corrins and vitamin B12.4... 

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