Secondary sources of chemical information

A,3. SECONDARY SOURCES OF CHEMICAL INFORMATION. ABSTRACTING JOURNALS... 

There is still a gap between our models of liquid-state reactions and the often bewildering complexity of real chemical systems. Progress in shortening the gap will probably come only from the application of a variety of methods to this problem. The full promise of picosecond spectroscopy techniques for studying the details of the dynamics of reactive events in liquids has yet to be realized. How deeply can these methods probe the dynamics Computer simulations, another source of experimental information in reacting systems, are only beginning to be exploited. "" The description by direct computer simulation of both primary and secondary recombination dynamics, for example, would yield a wealth of information that could be used to test theories. 

ABSTRACT. An attempt to construct the literature databases for inclusion complexes since the beginning of this century is illustrated. The original literatures were cited and cross-checked by several secondary sources including Chemical Abstracts. The existing database systems appear to be insufficient to obtain necessary information effi-... 

N. Trinajstic and T. Toth, Interactions between users and the secondary sources of information A case study of Chemical Abstract Services, Kem. Ind. (Zagreb) 35 (1986) 527-550. 

Besides the NOE, the NMR technique offers other information that can also be used in structure determination. Spin-spin coupling constants are a traditional source of such information, and it is becoming increasingly clear that the chemical shifts in proteins and nucleic acids can often give direct information on the secondary and tertiary structure since they depend upon the local environment. This additional NMR information can be used at several levels. Coupling constant information is often converted to dihedral angle constraints and used in a manner similar to the distance constraints derived from NOE information. Because of the complexity of the interactions that influence the chemical shift, this information is more useful at the final structure refinement stage, where the overall structure has already been determined. 

TOXLINE (non-royalty based) Toxicology Information Online National Library of Medicine 8600 Roekville Pike Bethesda, MD 20894 (301) 496-1131 On-line bibliographic database covering the pharmacological, physiological, and toxicological effects of drugs and chemicals. Information is taken from eleven secondary sources. 

Cyanobacterial toxins (both marine and freshwater) are functionally and chemically a diverse group of secondary chemicals. They show structure and function similarities to higher plant and algal toxins. Of particular importance to this publication is the production of toxins which appear to be identical with saxitoxin and neosaxitoxin. Since these are the primary toxins involved in cases of paralytic shellfish poisons, these aphantoxins could be a source of PSP standards and the study of their production by Aphanizomenon can provide information on the biosynthesis of PSP s. The cyanobacteria toxins have not received extensive attention since they have fewer vectors by which they come in contact with humans. As freshwater supplies become more eutrophicated and as cyanobacteria are increasingly used as a source of single cell protein toxic cyanobacteria will have increased importance (39). The study of these cyanobacterial toxins can contribute to a better understanding of seafood poisons. 

When we need the properties of a chemical compound, such as the boiling point of benzene, the fastest and least expensive method is a forward search from the structure to the properties by consulting a database. The sources of such experimental information are first published in primary research journals, and then pass through professional editors and panels to make their way to secondary textbooks and handbooks. 

Allylic hydroperoxides are primary products in the autoxidation of - olefins, and lack of definite information on their reactivity and chemical behavior has hampered efforts to understand olefin oxidation mechanisms (2). This deficiency is most strongly felt in determining the relative rates of addition and abstraction mechanisms for acyclic olefins since assignment of secondary reaction products to the correct primary source is required. Whereas generalizations about the effect of structure on the course of hydroperoxide decompositions are helpful, most questions can be answered better by directly isolating the hydroperoxides involved and observing the products formed by decomposition of the pure compounds. 

The Toxicology Information Services at the Karolinska Institutet 1n Stockholm, Sweden, publish a monthly bulletin entitled Teratology Lookout. This excellent source of references of interest to experimental teratologists and clinicians is compiled by an advisory panel. The secondary sources Biological Abstracts, Biological Abstracts/RRM, and Chemical Abstracts and the MEDLARS data bases are scanned by the use of computer profiles to spot pertinent material. Keywords have been added to each reference, and most references include author addresses. The contents are divided into seven... 

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