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Chemical Structure and Classification

Cationic functionality is found in various types of dyes, mainly in cationic azo dyes (Section 3.7) and methine dyes (Section 3.8), but also in anthraquinone (Section 3.4), di- and triarylcarbenium (Section 2.6), phthalocyanine dyes (Section 2.7), and in various polycarbocyclic and solvent dyes (Section 3.10). [Pg.45]

This chapter gives a short survey on cationic dyes and shows typical representatives of each class of cationic dyes. In general, the dyes are classified according to their chemical structure. [Pg.45]


The large number and diversity of available /3-lactams, mainly penicillins and cephalosporins, necessitate their classification. Penicillins can be classified primarily according to chemical structure. Table 5.2 shows that there is good correspondence between chemical structure and properties. The categorization of cephalosporins into chemically similar groups is not useful because their antimicrobial spectrum is not closely correlated with chemical structure, and classification into generations is based on their spectrum of microbial activity (Table 5.3). [Pg.184]

PLANT Sources, chemical structures and classifications of natural phthalides Chemical Structure of Phthalide... [Pg.612]

As explained in Chapter 8, descriptors are used to represent a chemical structure and, thus, to provide a coding which allows electronic processing of chemical data. The example given here shows how a GA is used to Rnd an optimal set of descriptors for the task of classification using a Kohoncii neural network. The chromosomes of the GA are to be used as a means for selecting the descriptors they indicate which descriptors are used and which are rejected ... [Pg.471]

ChemIDplus. Published by the U.S. National Library of Medicine, ChemIDplus [62] is a web-based search system, http //chem.sis.nlm.nih.gov/ chemidplus/, that provides free access to structure and nomenclature authority files used for the identification of chemical substances cited in National Library of Medicine (NLM) databases. ChemIDplus also provides structure searching and direct links to biomedical resources at NLM and on the Internet. The database contains over 349,000 chemical records, over 56,000 of which include chemical structures, and is searchable by name, synonym, CAS registry number, molecular formula, classification code, locator code, and structure. [Pg.772]

Because of multiple receptor actions, which occur at different concentrations, different neuroleptics have different action profiles. There are many classifications for neuroleptic drugs, the least useful of which is probably based on their chemical structure. Other classifications include linear classifications based on the propensity to cause EPS, or multidimensional ones such as the Liege star which combines information on three positive effects (anti-autistic, antiproductive, antipsychotic), and three negative (hypotensive, extrapyramidal, sedative). In a general way, the more sedative neuroleptics such as levomepromazine, used more to treat acute agitation states, cause more hypotension related to alpha blockade, whereas those that act best on delirium (productive states) such as haloperidol tend to cause more EPS. [Pg.678]

TABLE 7-16. Classification of antidepressants by chemical structure and mechanisms of action... [Pg.130]

Classification of the anabolic steroids is based on chemical structures and associated actions. A review of the biosynthesis and metabolism of the naturally occurring estrogens and androgens is available (1). Names, descriptions, approval dates, and recommended doses of the commercial products are found in References 1, 8, and 9. Although steroids may be orally active, the FDA approved mode of administration is the subcutaneous implant. Effective dose is lower with implant rather than oral administration. [Pg.409]

Know the names, structures, and classification of all amino acids and their side chains present in proteins, and be familiar with their physical and chemical properties, such as conformation, absorption of ultraviolet light, and reactions with ninhydrin. [Pg.45]

Lactamases are heterologous in nature both in terms of their chemical structure and their substrate profile [181] (Table 4.13). The original Rich-mond-Sykes [182] classification of -lactamases produced by Gram-negative bacteria envisaged five classes of enzymes. Of these, class I had a cephalo-... [Pg.162]

The carbamate esters fall into two general classes according to their chemical structure and biological activity. The 7V-methylcarbamates are insecticides while the iV-arylcarbamates are mainly herbicides. Since this classification is not entirely rigorous and they are structurally related, both classes are here considered together. [Pg.77]

Polymers can be usefully classified in many ways, such as by source of raw materials, method of synthesis, end use, and fabrication processes. Some classifications have already been considered in this chapter. Polymers are grouped by end use in this section, which brings out an important difference between macromolecules and other common materials of construction. This is that the chemical structure and size of a polymeric species may not completely determine the properties of an article made from such a material. The process whereby the article is made may also exert an important influence. [Pg.24]

Strunz Mineralogical Tables. Chemical-Structural Mineral Classification System. / by Hugo Strunz and Ernest H. Nickel. 9th ed - Stuttgart, Schweizerbart, 2001 ISBN 3-510-65188-X... [Pg.2]

The chemical-structural mineral classification system developed since the first edition of Mineralogische Tabellen (1941) evolved from the chemical miiieral system of Hatiy (1801), which was based on cations, and of Berzelius (1814,1824), based on anions, followed by the chemical-morphological system of Gustav Rose (1838,1852), the periodic system of the chemical elements (c Introduction), and finally by the developing knowledge of atomic crystal structures (since Laue, 1912, Bragg, 1913). [Pg.24]

Today s commercially available pesticides are characterized by a vast variety of chemical structures and functional groups making their chemical classification quite complex. The major chemical groups are as follows ... [Pg.140]

While we have used a classification based on chemical structure, alternative classifications based on experimental techniques or chemical stability are frequently encountered. These afford a somewhat different and certainly useful perspective of the field, and are outlined below. [Pg.69]


See other pages where Chemical Structure and Classification is mentioned: [Pg.153]    [Pg.45]    [Pg.45]    [Pg.47]    [Pg.49]    [Pg.51]    [Pg.1037]    [Pg.1231]    [Pg.281]    [Pg.153]    [Pg.45]    [Pg.45]    [Pg.47]    [Pg.49]    [Pg.51]    [Pg.1037]    [Pg.1231]    [Pg.281]    [Pg.658]    [Pg.421]    [Pg.575]    [Pg.307]    [Pg.555]    [Pg.92]    [Pg.87]    [Pg.430]    [Pg.58]    [Pg.159]    [Pg.4]    [Pg.337]    [Pg.767]    [Pg.70]    [Pg.194]    [Pg.314]    [Pg.127]    [Pg.224]    [Pg.1239]   


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