Isolation and identification

NH2-C0-NH NH2,CH5N30. Colourless crystalline substance m.p. 96" C. Prepared by the electrolytic reduction of nitrourea in 20% sulphuric acid at 10 "C. Forms crystalline salts with acids. Reacts with aldehydes and ketones to give semicarbazones. Used for the isolation and identification of aldehydes and ketones. 

Testosterone and estradiol are present m the body m only minute amounts and their isolation and identification required heroic efforts In order to obtain 0 012 g of estradiol for study for example 4 tons of sow ovaries had to be extracted ... 

A. D. Kiishenbaum and A. V. Giosse, Production, Isolation, and Identification ofithe -OF O F, and - O FRadical s, Research Institute, Temple Univeisity, Pbiladelpbia, Pa., June 1964. 

B. D. Mookherjee and R. Patel, "Isolation and Identification of Volatile Constituents of Tiacture of Ambergris," paper presented at the FTIth International Congress of Essential Oils, Oct. 7—11, 1977, Ityoto, Japan. 

Analytical Approaches. Different analytical techniques have been appHed to each fraction to determine its molecular composition. As the molecular weight increases, complexity increasingly shifts the level of analytical detail from quantification of most individual species in the naphtha to average molecular descriptions in the vacuum residuum. For the naphtha, classical techniques allow the isolation and identification of individual compounds by physical properties. Gas chromatographic (gc) resolution allows almost every compound having less than eight carbon atoms to be measured separately. The combination of gc with mass spectrometry (gc/ms) can be used for quantitation purposes when compounds are not well-resolved by gc. 

TYZOR ET is reduced by sodium and ethanol to a dark-blue compound (182). Use of potassium as the reducing agent in the alcohol permits the isolation and identification of Ti(OC2H2)3 [22922-82-3] and Ti(OC4Hg)3 [5058-41-3] (183,184). The products precipitate as soUd alcoholates,... 

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 Wilkinson hydrogenation cycle shown in Figure 3 (16) was worked out in experiments that included isolation and identification of individual rhodium complexes, measurements of equiUbria of individual steps, deterrnination of rates of individual steps under conditions of stoichiometric reaction with certain reactants missing so that the catalytic cycle could not occur, and deterrnination of rates of the overall catalytic reaction. The cycle demonstrates some generally important points about catalysis the predominant species present in the reacting solution and the only ones that are easily observable by spectroscopic methods, eg, RhCl[P(CgH 2]3> 6 5)312 (olefin), and RhCl2[P(CgH )2]4, are outside the cycle, possibly in virtual equiUbrium with... 

The earliest references to cinnamic acid, cinnamaldehyde, and cinnamyl alcohol are associated with thek isolation and identification as odor-producing constituents in a variety of botanical extracts. It is now generally accepted that the aromatic amino acid L-phenylalanine [63-91-2] a primary end product of the Shikimic Acid Pathway, is the precursor for the biosynthesis of these phenylpropanoids in higher plants (1,2). 

In recent year s, clinical studies on the role of uiinai y luodified nucleosides as the biochemical mai kers of various types of cancer have been actively undertaken. Most of the urinai y modified nucleosides ai e piimai ily originated by methylation of either the base part, the sugar hydroxyl par t, or in some cases, both par ts of the course of biodegradation of tRNA molecules. Hence, their isolation and identification plays a major role in biochemical analysis. 

Isolation and identification of substances (natural products from nature, protein purification and characterisation, etc). 

Isolation and Identification of Giardia Cysts, Cryptosporidium Oocysts and Eree Living Pathogenic Amoebae in Water etc., 1989... 

ATPase inhibitor. In such patients, inhibition of the sodium pump in the cells lining the blood vessel wall results in accumulation of sodium and calcium in these cells and the narrowing of the vessels to create hypertension. An 8-year study aimed at the isolation and identification of the agent responsible for these effects by researchers at the University of Maryland Medical School and the Upjohn Laboratories in Michigan recently yielded a surprising result. Mass spectrometric analysis of compounds isolated from many hundreds of gallons of blood plasma has revealed that the hypertensive agent is ouabain itself or a closely related molecule ... 

The isolation and identification of 4 radioactive elements in minute amounts took place at the turn of the century, and in each case the insight provided by the periodic classification into the predicted chemical properties of these elements proved invaluable. Marie Curie identified polonium in 1898 and, later in the same year working with Pierre Curie, isolated radium. Actinium followed in 1899 (A. Debierne) and the heaviest noble gas, radon, in 1900 (F. E. Dorn). Details will be found in later chapters which also recount the discoveries made in the present century of protactinium (O. Hahn and Lise Meitner, 1917), hafnium (D. Coster and G. von Hevesey, 1923), rhenium (W. Noddack, Ida Tacke and O. Berg, 1925), technetium (C. Perrier and E. Segre, 1937), francium (Marguerite Percy, 1939) and promethium (J. A. Marinsky, L. E. Glendenin and C. D. Coryell, 1945). 

The oldest effective drug for the treatment of this disease is indisputably quinine. Although the antipyretic activity of cinchona bark was known to the Incas, it remained for the Jesuit missionaries to uncover its antimalarial properties in the early seventeenth century. The advance of organic chemistry led to the isolation and identification of the alkaloid, quinine, as the active compound at the turn of this century. The emerging clinical importance of this drug led up to the establishment of cinchona plantations in the Dutch East Indies. This very circum-... 

The purpose of this paper, then, is to summarize the present condition of some of the work done in this and other laboratories and present information on the separation, isolation, and identification of some of the components of pyrethrum. Work of others has, in part, been confirmed and some new evidence is presented on compounds isolated from the pyrethrum mixture. 

The first five telomers (n = 1 - 5) were isolated and identificated. The authors showed that telomers T2 and T3 are preferentially formed in one stereoisomeric form (with minor amounts of other possible isomers), i.e. the radical addition reaction makes it possible to perform asymmetric control at the steps of chain transfer and chain growth. The partial chain transfer constants Cn are given in this work, which are within the range from 0.3 to 0.5 for radicals C2-C5. We consider... 

Table 2.1 HPLC capacity factors for secbuto-barbitone and vinbarbitone with an octadecyl silyl stationary phase and mobile phases of methanoiyO.l M sodium dihydrogen phosphate (40 60) at (a) pH 3.5, and (b) pH 8.5. From Moffat, A.C. (Ed.), Clarke s Isolation and Identification of Drugs, 2nd Edn, The Pharmaceutical Press, London, 1986. Reproduced by permission of The Royal Pharmaceutical Society...

Extensive and careful experimentation is actually required to demonstrate the involvement, isolation and identification of gases in chemical reactions. 

Starr, M.P., Stolp, H., Triiper, H.G., Balows, A. and Schlegel, H.G. 1981 The Prokaryotes A Handbook on Habitats, Isolation, and Identification of Bacteria. Vol. 1. Berlin, Springer-Verlag. Turban-Just, S. in preparation Biogene Dekomposition von Knochenprotein. Ph.D. dissertation, Miinchen. 

Chopra NM, Campbell BS, Hurley JC. 1978. Systematic studies on the breakdown of endosulfan in tobacco smokes Isolation and identification of the degradation products from the pyrolysis of endosulfan I in a nitrogen atmosphere. J Agric Food Chem 26 255-258. 

Korte, F. and Arent, H. (1965). Metabolism of Insecticides IX Isolation and identification of dieldrin metabolites from urine of rabbits after oral administration of C-14 dieldrin. Life Sciences 4, 2017-2026. 

Stratton, S.P., Schaefer, W.H., and Liebler, D.C., Isolation and identification of singlet oxygen oxidation products of beta-carotene, Ghent. Res. Toxicol, 6, 542, 1993. 

Schwarz, M., Wray, V., and Winterhalter, P., Isolation and identification of novel pyranoanthocyanins from black carrot (Daucus carota L.) juice, J. Agric. Food Chem.,... 

Alard, D. et al., Neobetanin isolation and identification from Beta vulgaris. Phytochemistry, 24, 2383, 1985. 

Merghem, R., Qualitative analysis and HPLC isolation and identification of procya-nidins from Vicia faba, Phytochem. Anal., 15, 95, 2004. 

Collier TK, LC Thomas, DC Malins (1978) Influence of environmental temprature on disposition of dietary naphthalene in coho salmon (Oncorhynchus kisutch) isolation and identification of individual metabolites. Comp Biochem Physiol 61C 23-28. 

Sendoo K, H Wada (1989) Isolation and identification of an aerobic y-HCH-decomposing bacterium from soil. Soil Sci Plant Nutr 35 79-87. 

Weissenfels WD, M Beyer, 1 Klein, HI Rehm (1991) Microbial metabolism of finoranthene isolation and identification of fission prodncts. Appl Microbiol Biotechnol 34 528-535. 

Moffat AC et al. (1986) Clarke s isolation and identification of drugs. The Pharmaceutical Press, London... 

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