CAS online system

A more exhaustive search for cognate substructures can be carried out with the CAS Online System, where more than 600000 substances are searchable through Chemical Abstracts, in France the DARC system is used similarly. In this approach, some biological data will be delivered directly, but more can often be obtained by inserting the CAS number of the substance into the US National Institute of Health s MEDLARS system (available without charge in many countries through local Departments of Health). 

Stmcture searching and display software are host-specific. The Softon Substmcture Search System (S4) was developed by the Beilstein Institute and Softon of Graefelfing Germany (50). It is a full stmcture and substmcture searching module. The S4 is used in-house by the Beilstein Institute and is operated by DIALOG. STN uses CAS ONLINE s messenger software for on-line stmcture searching of the Beilstein on-line database (51). 

A number of files under the generic tide CAS ONLINE are available on-line on STN International. The system software, MESSENGER, includes chemical substmcture, text, and numeric data searching facHities. Chemical stmctures and Registry Numbers are contained in the CA Registry file. The four ways to search the stmctures are EXA, EAM, SSS, and CSS. 

Description, Acquisition, Retrieval, and Correlation File. This is the only other pubhc substmcture search system, apart from CAS Online, that provides full access to the CAS Chemical Registry File. The DARC file, commercially available on-line from Telesystems-Questel, offered the first pubhc on-line implementation of substmctural searching of the CAS Chemical Registry System. The advantages and disadvantages of the CAS Online and DARC systems have been discussed (49). 

CAS Registry Number (CASRN) This unique identifier is assigned by the American Chemical Society to chemicals recorded in the CAS Registry System. This number is used to access various chemical databases including the Hazardous Substances Data Bank (HSDB), CAS Online, Chemical Substances Information Network, and many others. This entry is also useful to conclusively identify a substance regardless of the assigned name. 

CAS ONLINE American Chemical Society, Columbus, Ohio CAS ONLINE The Chemical Search System From Chemical Abstracts Service 1967-present CHEMICAL ABSTRACTS SERVICE Equivalent of the printed Chemical Abstraets(CA). Bibliographic data, keyword phrases, index entries, general subject headings, and CAS Registry Number(s) for chemistry-related publications in 50 languages from 150 countries. Includes worldwide patent documents. Easy crossover to the CAS CHEMICAL REGISTRY... 

CAS Registry Numbers are included in the printed Chemical Abstracts chemical substance and formula indexes and in the CAS databases. The full set of CAS Chemical Registry System database information—structures, names, formulas, and ring data—is available for search and display through STN International, SciFinder, and other CAS search services. CAS Registry information is also available in CAS databases offered by other online system vendors. 

In-house chemical information management systems began to emerge at some of the larger chemical and pharmaceutical firms. These included CONTRAST and SOCRATES at Pfizer, SYNLIB at SmithKline, COUSIN at Upjohn, MSDRL/CSIS at Merck, and CROSSBOW at ICI (27). The Chemical Abstracts database was made available online in 1967 (28). In 1980 this became CAS ONLINE. A compre-... 

This collection contains full text Material Safety Data Sheets, Summary Sheets, and Label Data for more than 59000 substances, including pure substances and mixtures, 92-96% of which are the most heavily used chemicals in industry. The database originated with Occupational Health Services, Inc. (OHS). The records include occupational, environmental, and regulatory data, as well as names, CAS Registry Numbers, and regulatory list numbers. The OHS online system provides a full file, a summary information file, and a file composed of records to chemicals used in the manufacture of pesticide and other agricultural chemical products (OHS, STN available on CD from OHS). 

Dittmar PG, Farmer NA, Fisanick W, Haines RC, Mockus J. The CAS ONLINE search system 1. General system design and selection, generation, and use of search screens. J Chem Inf Comput Sci 1983 23 93-102. 

CAS ONLINE is Chemical Abstracts Service s computerized system that provides access to substance information from the CAS registry file. CAS ONLINE allows users to search for substances on the basis of structural units, registry number, chemical name, or molecular formula. Portions of the CAS information base are licensed by several information vendors. 

A collection of approximately 47,400 zeotropic and azeotropic data sets, compiled from 6600 references, are stored in a comprehensive computerized data bank (Reference 10). The references from the above-mentioned compilations and from the vapor-liquid equilibrium part of the Dortmund Data Bank (Reference 11) were supplemented by references found from CAS online searches, private communications, data from industry, etc.. Over 24,000 zeotropic data and over 20,000 azeotropic data are available for binary systems. Nearly 90% of the binary azeotropic data show a pressure maximum. In most cases (ca. 90%) these are homogeneous azeotropes, and in approximately 7-8% of the cases heterogeneous azeotropes are reported. Less than 10% of the data stored show a pressure minimum. Approximately 21,000 of the data sets stored were published after 1970. 

The chemical structure files built by these software packages consist of connection tables, a form of structural representation used in the CAS Chemical Registry System, and in consequence by both CAS ONLINE and DARC, and incidentally in many other systems (including MACCS). Both CPSS and PSIDOM include modules for building chemical structure data bases on personal computers which, in the case of PSIDOM, are limited only by the capacity of the disk storage... 

In the past few years, several microcomputer-based software packages have become available to input and store chemical structures. These packages can be divided into two main groups those that allow structures to be drawn and stored for later recall [e.g., ChemDraw (S. Rubenstein), WIMP (Aldrich)] and those that capture structures from online files like Index Chemicus Online and CAS ONLINE [e., PC-Plot (MicroPlot), Emu-Tek (FTG Data Systems)]. The greatest limitation of both groups of software is that stored structures have to be recalled serially or by specific registration number since structure and sub-structure search capabilities are not available. 

Connection tabie systems (CAS ONLINE, DARC, MACCS)... 

CAS ONLINE - Online chemical information system, service available from Chemical Abstracts Service, P.O. Box 3012, Columbus, Ohio 43210, U.S.A. 

Our full structure search system determines the possible Chemical Abstracts Service (CAS) registry numbers and internal compound numbers for a given structural drawing. Additionally the user can select from a set of predefined keyword profiles and submit a job for CAS ONLINE. A minicomputer will set up the query, call the host system, perform the search, capture the answers and inform the user that the job was successfully completed. The user can now play back the answers at his terminal with structural formulae, bibliography and abstracts. The only activities are structure drawing, menu selection, waiting and scanning the results. 

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