May 23, 2022

  • Updated
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CAS Lexicon Query Builder

The CAS Lexicon Query Builder allows users to browse CAS Indexed Concepts and Substances within the CAS General Thesaurus hierarchy and then build reference queries with up to 1,000 terms. Only CAS Concepts are considered in the search; MEDLINE Medical Subject Headings or Supplementary Concepts are not searched, but MEDLINE results that are duplicates of CAPlus references are included in the results.

Upon selecting the References search type on the homepage, users now see a Launch CAS Lexicon button.


Clicking the Launch CAS Lexicon button opens the Search CAS Lexicon page in a new tab.


When a term or terms has been added to the text box, clicking the Search Concept button initiates the search within the CAS Lexicon.

Searching within the CAS Lexicon looks for partial exact matches on CAS Preferred, Non-Preferred, and Previously Indexed terms for both Concepts and Substances. If there is a match, the corresponding Preferred Term is displayed. Searching a term from the Lexicon searches it as either an Indexed Concept or Indexed Substance in a document. If there are multiple hits, the user is presented with a list of up to 1,000 Preferred Terms from which to choose.

  1. The list of Preferred Terms is sorted in the following order:
  2. Exact match to the preferred term
  3. Partial match to the preferred term
  4. Exact match to a synonym
  5. Partial match to a synonym


Selecting one of the Preferred Terms displays that Preferred Term’s Thesaurus Hierarchy, including synonyms, with the Preferred Term selected by default.


To build the query, select one or more terms from the displayed hierarchy and then click the Add Term(s) button, which adds the selected terms to the Your Query field. When adding terms to Your Query, the terms in the viewed hierarchy are automatically deselected.


Additional terms can be added to Your Query by selecting terms and choosing a Boolean operator. Users may also search for additional preferred terms unrelated to the currently viewed hierarchy to add them to the query. Up to 1,000 terms can be added to Your Query.


Clicking the Add Term(s) button adds the additional term(s) to the query. Individual search terms can be deleted from Your Query by clicking the X next to the search term; clicking the Clear All link clears all search terms. Clicking the search (magnifying glass) button initiates the CAS Lexicon Search.


After conducting a CAS Lexicon search, the Recent Search History and History page entries are listed as a References search with a query labelled CAS Lexicon followed by the searched terms and associated Boolean operators.


Biosequence Global Crossover Modifications

Upon viewing a biosequence result set whose global crossover would retrieve more than 1000 patent documents, the global References crossover button appears inactive and an associated, dismissible message also displays.


To enable the global References crossover, the user should modify the query or filter the result set to limit the referenced patents to less than 1000.

Download MOLFiles and SDFiles in V3000 Format

The option to download .mol and .sdf files in V3000 format was added to the appropriate download menus.


V3000 .mol files can be downloaded from substance flyout menus and substance detail pages; V3000 .sdf files can be downloaded from substance flyout menus, substance detail pages, and substance result set pages.