Chemical Abstracts Services

The term has different spellings Chemoinformatics and Cheminformatics. Searches in the database of the Chemical Abstracts Service have shown an approximately equal number of hits for both terms, with Cheminformatics gaining ground somewhat in recent years. Here, we use the spelling "Chemoinformatics" without trying to put forward reasons for that choice. 

The systematic lUPAC nomenclature of compounds tries to characterize compounds by a unique name. The names are quite often not as compact as the trivial names, which are short and simple to memorize. In fact, the lUPAC name can be quite long and cumbersome. This is one reason why trivial names are still heavily used today. The basic aim of the lUPAC nomenclature is to describe particular parts of the structure (fi agments) in a systematic manner, with special expressions from a vocabulary of terms. Therefore, the systematic nomenclature can be, and is, used in database systems such as the Chemical Abstracts Service (see Section 5.4) as index for chemical structures. However, this notation does not directly allow the extraction of additional information about the molecule, such as bond orders or molecular weight. 

The WLN was applied to indexing the Chemical Structure Index (CSI) at the Institute for Scientific Information (ISI) [13] and the Ituiex Chemicus Registry System (ICRS) as well as the Crossbow System of Imperial Chemical Industries (ICl). With the introduction of connection tables in the Chemical Abstracts Service (CAS) in 1965 and the advent of molecular editors in the 1970s, which directly produced connection tables, the WLN lost its importance. 

In the ancient times" the 1950s), data were transferred to computers by using punched cards. But already in 1959 Ascher Opier from Dow Chemical Company reported the use of a light pen for graphical entiy of chemical structures into a computer. Light pens were also used in the Chemical Abstracts Service in the 1970s. 

More than 10 000 databases exist that provide a small or large amount of data on various topics (including chemistry). The contents in databases are supplied by approximately 3500 database developers (e.g., the Chemical Abstracts Service, MDL Information Systems, etc.). Since there is a variety of topics from economics to science, as well as a variety of structures of the database, only some of the vendors (-2000) offer one or more databases as either local or as online databases (Figure 5-4) [4]. Usually, databases are provided by hosts that permit direct access to more than one database. The search occurs primarily through different individual soft-... 

Typical bibliographic databases are the CA File of Chemical Abstracts Service CAS) or Medline of the US National Library of Medicine. Most electronic journals provide articles as full-text files, e.g., the Journal of the American Chemical Society ( ACS). 

CA FUe Chemical Abstracts Service biochemistry, chemistry, and chemical engineering bibho. >21mio substances >25mio sequences 9000 journals, 37 patent offices, proceedings, books STN commercial CD-ROM, online weekly www.cas.org... 

CASREACT Chemical Abstracts Service chemical reactions biblio., reaction, struc- ture >400 000 documents >6.6 mio reactions journals, patents STN commercial CD-ROM, online weekly WUW.CflS.OTg... 

It can be said that these three main strategies have been applied equally and very often in combination. Basically, the first approach implies the use of a faster computer or a parallel architecture. To some extent it sounds like a brute force approach but the exponential increase of the computer power observed since 1970 has made the hardware solution one of the most popular approaches. The Chemical Abstracts Service (CAS) [10] was among first to use the hardware solution by distributing the CAS database onto several machines. 

B and W J Howe 1991. Computer Design of Bioactive Molecules - A Method for Receptor-Based Novo Ligand Design. Proteins Structure, Function and Genetics 11 314-328. i H L 1965. The Generation of a Unique Machine Description for Chemical Structures - A hnique Developed at Chemical Abstracts Service. Journal of Chemical Documentation 5 107-113. J 1995. Computer-aided Estimation of Symthetic Accessibility. PhD thesis. University of Leeds, itan R, N Bauman, J S Dixon and R Venkataraghavan 1987. Topological Torsion A New )lecular Descriptor for SAR Applications. Comparison with Other Descriptors. Journal of emical Information and Computer Science 27 82-85. 

The lUPAC rules are not the only nomenclature system in use today Chemical Abstracts Service sur veys all the worlds leading scientific journals that publish papers relating to chemistry and publishes brief abstracts of those papers The publication Chemical Abstracts and its indexes are absolutely es sential to the practice of chemistry For many years Chemical Abstracts nomenclature was very similar to lUPAC nomenclature but the tremendous explosion of chemical knowledge has required Chemical Abstracts to modify Its nomenclature so that its indexes are better adapted to computerized searching This means that whenever feasible a compound has a sin gle Chemical Abstracts name Unfortunately this Chemical Abstracts name may be different from any of the several lUPAC names In general it is easier to make the mental connection between a chemical structure and its lUPAC name than its Chemical Abstracts name... 

When compounds of complex structure are considered, the number of name possibilities grows rapidly. To avoid having index entries for all possible names. Chemical Abstracts Service has developed what might be called the principle of inversion. The indexing system employs inverted... 

Quite naturally there is a certain amount of arbitrariness in this system, although the lUPAC nomenclature is followed. The preferred Chemical Abstracts index names for chemical substances have been, with very few exceptions, continued unchanged (since 1972) as set forth in the Ninth Collective Index Guide and in a journal article. Any revisions appear in the updated Index Guide new editions appear at 18-month intervals. Appendix VI is of particular interest to chemists. Reprints of the Appendix may be purchased from Chemical Abstracts Service, Marketing Division, P.O. Box 3012, Columbus, Ohio 43210. 

CAST-3D The Chemical Abstracts Service 3-D Stmcture DB Chemical Abstracts Service... 

NOTE ON CHEMICAL ABSTRACTS SERVICE REGISTRY NUMBERS AND NOMENCLATURE... 

CAS/STlS[Interna.tiona.1. CAS/STN offers stmcture searchable files such as Registry, Beilstein, MARPAT, CASREACT, and Gmelin a variety of learning files, eg, LRegistry, LBeHstein, LMARPAT, and LCASREACT and software products such as STN Express for on-line stmcture and substmcture searching. Chemical Abstracts Service, a division of the American Chemical Society, has pubHshed Chemical Abstracts since 1907 and joindy operates STN International with EIZ Kadsmhe and the Japan Information Center of Science and Technology. 

MARPAT, produced by Chemical Abstracts Service, coataias the geaeric stmcture records for pateat pubHcatioas siace 1988, which are iacluded ia the CA file. Sources iaclude pateats from 26 couatries plus EPO and PCT pubHcations. BibHographic records for retrieved references can be direcdy accessed ia this database (101). 

GORE. The CORE Electronic Chemistry Library is a joint project of Cornell University, OCLC (On-line Computer Library Center), Bell Communications Research (Bellcore), and the American Chemical Society. The CORE database will contain the full text of American Chemical Society Journals from 1980, associated information from Chemical Abstracts Service, and selected reference texts. It will provide machine-readable text that can be searched and displayed, graphical representations of equations and figures, and full-page document images. The project will examine the performance obtained by the use of a traditional printed index as compared with a hypertext system (SUPERBOOK) and a document retrieval system (Pixlook) (6,116). 

R. J. Massie, The American Chemical Society and Dialog Information Services Settle Litigation, press release. Chemical Abstract Service, Columbus, Ohio, Oct. 29,1993. 

July 1993 STN Database Catalog, Chemical Abstracts Service, Columbus, Ohio, 1993, p. 4. 

The concept of the principal function raises the question of how priority is deterrnined when two or more different functional groups are present. No arbitrary rule can be entirely satisfactory, but an order has been codified in lUPAC recommendations (52—54), and an essentially similar order is used by Chemical Abstracts Service. In general, a higher state of oxidation takes precedence over a lower one, as shown in Table 1. 

USPATFULL STN Chemical Abstracts Service U.S. full bibhographic data full text Chemical Abstracts indexing from U.S. patent or equivalent... 

CA File, CAPlus, CA Previews STN Chemical Abstracts Service international, chemistry limited bibhographic data comprehensive English language abstracts deep indexing of chemical concepts stmcture-searchable compound registry chemical stmcture drawings... 

MARPAT, MARPAT Previews STN Chemical Abstracts Service international, chemistry stmcture-searchable Markush formulas in addition to other data searchable in the CA FUe, CAPlus, or CA Previews... 

Chemical Abstracts Service. The Chemical Abstracts Service (CAS), a division of the American Chemical Society, has produced Chemical Abstracts (CA) since 1907. Since the demise of Chemisches Zentralblatt and British Chemical Abstracts CA has been the preeminent medium for documenting new pubhcations in the field of chemistry and chemical engineering. CA documents chemical pubHcations of all types. It is not a patent database per se, but its patent component is larger than most databases devoted entirely to patents. Thus, for example, the number of patent references in CA for the years 1991—1993 ranged from 95,500—99,400 per year. 

Naming and Indexing of Chemical Substances for Chemical Abstracts, Chemical Abstracts Service, American Chemical Society, Washington, D.C., 1992. Nomenclature of Organic Chemist, lUPAC, Pergamon Press, New York, 1979. 

CA.S Index Guide, Chemical Abstract Service, Columbus, Ohio, 1982, Appendix 4. 

In 1990, Chemical Abstracts Service listed over 10 million substances in their Registry. Moreover, the growth of new compounds is exponential, lea ding to a doubling of known chemicals every eleven years. Thus there is an ever increasing need to efficiendy identify substances and quantitate material with high confidence. Hyphenated instmments, combinations of accepted instmmental techniques where the sample is passed from one instmment directiy into another, were developed to aid in solving this problem (1). 

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