Chemistry, origin

Annatto is a colored pigment that is extracted from the Central and South American plant Bixa orellana. The color comes from the resinous outer covering of the seeds of the plant, which is composed of the carotenoid pigments bixin and norbixin and their esters. The central portion of those molecules is the same as that of the molecule beta-carotene, and the yellow-orange color of annatto comes from the same physical chemistry origins as the orange color of beta-carotene. 

This chapter briefly reviews the present understanding of the chemistry, origin, and distribution of the saxitoxins and methods for their detection. The second section of this chapter discusses studies on their pharmacology directed toward an understanding of the molecular basis for their strong, highly selective interaction with the sodium channel binding site. 

The first NNTRI drug candidate 2 was selected for development in 1992. Compound 2 exhibits very potent antivirus activity of IC50 = 12nM (inhibition HIV-1 RT using rC-dG template/primer). The Medicinal Chemistry original preparation route is depicted in Scheme 1.1 [2]. 

The presence of excess salt, particularly of bivalent inorganics can reduce the electrostatic repulsion between the anionic polymer and the kaolinite particles and enhance flocculation (24,25). The optimum flocculation of fine coal and coal refuse (which contained 13 to 65% clays) obtained by Lewellyn and Wang(24) with hydrolyzed polyacrylamide containing 70% acrylate in fact might have resulted from the use of recycled water which contained 55 ppm Ca and 30 ppm Mg. Other works in literature have reported maximum flocculation of kaolinite to occur with 30% hydrolyzed polyacrylamide (5,6,10,26,27). Such differences in reported results could easily result from variations in water chemistry, originating either with the water used or with dissolved organics released by the mineral itself. 

From a sampling of nineteenth-century statements about the aims of chemistry as a scientific discipline, Robert Friedel found the key words to be "composition," "properties," and "change." In Robert Friedel, "Defining Chemistry Origins of the Heroic Chemist," in Seymour Mauskopf, ed., Chemical Sciences in the Modern World. 

One of the founders of applied chemistry and faculty of engineering of Japan. President of Tokyo Gas Company. President of Chemical Society of Japan and Japan Society for Applied Chemistry Study of applied chemistry. Originator for the production of soda industry in Japan and the development of other chemical industries... 

With the recognition that rocks with aluminous intermediate chemistry originated as altered felsic volcanic rocks it is now possible to use these more broadly distributed rocks to target new deposits. 

Mitchell, R. H. 1996. Perovskites a revised classification scheme for an important rare earth element host in alkaline rocks. In Jones, A. P., Wall, F. Williams, C. T. (eds) Rare Earth Minerals, Chemistry, Origin and Ore Deposits. Chapman and Hall, London, 41-76. 

In the preceding chapters it has been seen that the chemical reactions in thermal ( dark ) chemistry originate from the ground state of a molecule, whereas photochemical reactions originate from its excited states. Photochemistry is therefore different from thermal chemistry because electronically excited molecules are different from ground state molecules. 

The main reactions of rhodium or iridium porphyrins are depicted in Scheme 3 and compiled in Table 6. This comparative table shows that not in all cases have the analogous situations been studied for rhodium and iridium porphyrins as a whole, a systematic study of iridium porphyrins has commenced only recently. As already mentioned in Table 4, the main starting materials are the aquachlo-rorhodium(III) or carbonylchloroiridium(III) species, i.e. the inspection of Scheme 3 will start from the compounds MC1(P)L (M = Rh L = H20) or MCl(P)CO (M = Ir). Alternative access to the chemistry of rhodium porphyrin chemistry originates at a bare Rh(II) species Rh(P) which is in equilibrium with its metal-metal bonded dimer, [Rh(P)]2 (paths q, — q see below). 

Supramolecular chemistry has been defined by one of its leading proponents, Jean-Marie Lehn, who won the Nobel Prize for his work in the area in 1987, as the chemistry of molecular assemblies and of the intermolecular bond . More colloquially this may be expressed as chemistry beyond the molecule . Other definitions include phrases such as the chemistry of the non-covalent bond and non-molecular chemistry . Originally supramolecular chemistry was defined in terms of the non-covalent interaction between a host and a guest molecule as highlighted in Figure 1.1, which illustrates the relationship between molecular and supramolecular chemistry in terms of both structures and function. 

Before 1985, six crystalline forms of carbon were known two forms of graphite, two forms of diamond, and chaoit and carbon (VI) discovered in 1968 and 1972, respectively. In addition a number of almost pure amorphous forms exist, such as polyacetylene (7.60) and cumulene (7.61) and recently a number of interesting nanostructured forms of carbon have been produced (Section 15.8). The year 1985 marked the discovery of the fullerenes, which represent the only truly pure molecular form of carbon, are produced under very extreme conditions as carbon vapour condenses in an atmosphere of an inert gas such as helium. Harold Kroto s interest in this chemistry originated with microwave spectroscopic studies of the atmosphere of stars and interstellar dust clouds. Kroto wanted to try to reproduce in the laboratory spectra of carbon... 

However, the technology of composite materials cannot be fully considered as a new chapter in the history of chemistry. Originally the term composite was used in conjunction with reinforced plastics. The US Society for Plastic Industries had a Reinforced Plastics Division which was renamed Reinforced Plastics and Composites Division, in 1967. [17] In France, a bi-monthly magazine entitled Plastique renforce/Verre textile published by the professional organization bearing the same name, started in 1963 and was rechristened in 1983 Composites with Plastique renforce/verre textile as a subtitle. The shift from reinforced plastics to composite... 

Pujol et al. in chapter eight, reviews the chemistry, origin and antiviral activities of naturally occurring sulfated polysaccharides for the prevention and control of viral infections such as HIV-1 and -2, human cytomegalovirus (HCMV), dengue virus (DENV), respiratory syncytial virus (RSV), and influenza A virus. 

Lazcano A, Bada JL. The 1953 Stalney L. Miller experiment fifty years of prebiotic organic chemistry. Origins Life Evol Biosphere 2003 33 235-42. 

Transition metal carbonyl chemistry originated with the discovery of [Ni(C0)4] in 1890. Although the first trifluorophosphine coordination complex was prepared the following year by Moissan (263) by treating... 

Green chemistry is a highly effective approach to pollution prevention because it applies innovative scientific solutions to real-world environmental situations. The 12 principles of green chemistry, originally developed by Paul Anastas and John Warner, provide a road map for chemists to implement green chemistry (see Table 12.1). 

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