Vitamin origin

The desugaring of cane juice concentrates the heat- and alkali-stable vitamins in the final molasses. Even after this accumulation, only myo-inositol may have reached the level of minimum dietary requirements.109 Niacin, pantothenic acid and riboflavin are also present in significant quantities109 the thiamine, pyridoxin, pantothenic acid, biotin and folic acid contents of molasses have been estimated by bioassay.110 111 The biotin content of Hawaiian and Cuban molasses was 2.1 and 1.7 gammas per gram, respectively.119 The antistiffness factor (closely related to stigmasterol) has been found in cane molasses.88 89 The distillery slop from the yeast fermentation of molasses is marketed as a vitamin concentrate this product also contains vitamins originating in the yeast. 

Richard Kuhn (Germany) for his work on carotenoids and vitamins. Originally the 1938 Nobel Prize nominations did not yield a suitable candidate, so the 1938 award was held until 1939, when it was awarded to Kuhn. Kuhn received the award for his work studying vitamins and carotenoids. He isolated and characterized the composition of numerous complexes, and also studied the optical properties of some of these species to differentiate those with different chemical structures. He... 

Cheese is produced from whole milk by the action of rennet, and contains nearly all the nutrients present initially. The resulting curd contains fat, calcium caseinate, calcium phosphate and most of the vitamins originally present in the milk. A comparatively small proportion of the protein, lipid, calcinm and phosphorus nutrients is lost in the discarded whey. 

The D vitamins originate from zJ > -unsaturated sterols, e.g., 7-dehydrocholesterol or ergosterol (D 6.4.1), by opening of ring B. This nonenzymatic reaction is mediated by UV light(A 260-285 nm). In animals D vitamins are hydroxylated... 

Occurrence— Vitamins originate primarily in plant tissues with the exceptions of vitamins C and D, they are present in animal tissues only if an animal consumes foods containing them or harbors microorganisms that synthesize them. Fat-soluble vitamins can occur in plant tissue in the form of a provitamin (or precursor of a vitamin), which can be converted into a vitamin in the animal body. But no provitamins are known for any water-soluble vitamin. Also, the B vitamins are universally distributed in all living tissues, whereas the fat-soluble vitamins are completely absent from some. 

Fig. V-60. Most vitamins originate in plants and they come in many different shapes, sizes, and colors. (Courtesy, California Dry Bean Advisory Board, Dinuba, Calif. 

The common name vitamin D is used throughout the pharmaceutical kidustry for simplicity. The trivial name calciferol has also been used extensively with the prefix ergo- and chole-, which kidicate vitamin D2 (2) and vitamin (4), respectively (see Steroids). Vitamin D2 was originally named calciferol in 1931 by Angus and co-wotkets (2). Historically, a number of substances were referred to as vitamin D and were distinguished from one another by a subscript numeral, eg, vitamin D2, vitamin D, etc. 

Vitamin E was first described ia 1922 and the name was originally applied to a material found ia vegetable oils. This material was found to be essential for fertility ia tats. It was not until the early 1980s that symptoms of vitamin E deficiency ia humans were recognized. Early work on the natural distribution, isolation, and identification can be attributed to Evans, Butt, and Emerson (University of California) and MattiU and Olcott (University of Iowa). Subsequentiy a group of substances (Eig. 1), which fall iato either the family of tocopherols or tocotrienols, were found to act like vitamin E (1 4). The stmcture of a-tocopherol was determined by degradation studies ia 1938 (5). 

The K vitamins are named after the original vitamin and the number of carbon atoms ia the side chain. Usiug this convention, vitamin K2 20) named because it contains 20 carbon atoms ia the chain. In the biological Hterature, vitamin is frequentiy referred to as menaquiaone and is further designated by the number of isoprene units ia the side chain. For example, vitamin 2(20) called menaquiaone-4 or MK-4. Vitamin is also referred... 

Plant and animal cells have numerous chromosomes. Growth rates are relatively slow. A typical nutrient medium will contain a large number of vitamins and growth factors in addition to complex nitrogen sources, because other specialized cells in the original structures supply these needs. A plant or animal cell is not hke a microbial cell in its ability to function independently. 

This series in heterocychc chemistry is being introduced to collectively make available critically and comprehensively reviewed hterature scattered in various journals as papers and review articles. All sorts of heterocyclic compounds originating from synthesis, natural products, marine products, insects, etc. will be covered. Several heterocyclic compounds play a significant role in maintaining life. Blood constituents hemoglobin and purines, as well as pyrimidines, are constituents of nucleic acid (DNA and RNA). Several amino acids, carbohydrates, vitamins, alkaloids, antibiotics, etc. are also heterocyclic compounds that are essential for life. Heterocyclic compounds are widely used in clinical practice as drugs, but all applications of heterocyclic medicines can not be discussed in detail. In addition to such applications, heterocyclic compounds also find several applications in the plastics industry, in photography as sensitizers and developers, and the in dye industry as dyes, etc. 

The presence of redox catalysts in the electrode coatings is not essential in the c s cited alx)ve because the entrapped redox species are of sufficient quantity to provide redox conductivity. However, the presence of an additional redox catalyst may be useful to support redox conductivity or when specific chemical redox catalysis is used. An excellent example of the latter is an analytical electrode for the low level detection of alkylating agents using a vitamin 8,2 epoxy polymer on basal plane pyrolytic graphite The preconcentration step involves irreversible oxidative addition of R-X to the Co complex (see Scheme 8, Sect. 4.4). The detection by reductive voltammetry, in a two electron step, releases R that can be protonated in the medium. Simultaneously the original Co complex is restored and the electrode can be re-used. Reproducible relations between preconcentration times as well as R-X concentrations in the test solutions and voltammetric peak currents were established. The detection limit for methyl iodide is in the submicromolar range. 

VITAMIN Bi2 IS FOUND ONLY IN FOODS OF ANIMAL ORIGIN... 

Similarly, 2,3,5-trimethyl-1,4-hydroquinone (TMHQ), a key intermediate in the synthesis of vitamin E, is produced via oxidation of 2,3,6-trimethylphenol to the corresponding benzoquinone. Originally this was performed by reaction with chlorine followed by hydrolysis, but this process has now been superseded by oxidation with O2 in the presence of a Cu2Cl2/LiCl catalyst (see Fig. 2.20) (Mercier and Chabardes, 1994). Alternatively, this oxidation can also be cataly.sed by a heteropolyanion (Kozhevnikov, 1995). 

To determine whether the loss of vitamin Bjj in microwave-treated foods was dne to the conversion of vitamin Bjj to some inactive vitamin B,2 degradation prodncts, the hydroxocobalamin that predominates in food was treated by microwave heating for 6 min and then analyzed by TLC on sihca gel 60 with -bntanol/2-propanol/water (10 7 10, v/v) as a solvent. The treated hydroxocobalamin was separated into fonr red spots intact hydroxocobalamin remained at the origin (Fignre 10.5) [10]. These hydroxocobalamin degradation products were further purified to homogeneity by the nse of TLC and HPLC and characterized. 

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