User guide

Query structures
A query is simply a search for information that is stored in a database. If you have ever searched the Internet using a
Web browser, then you have performed a simple query.
A query structure is a parameter you use to search a chemical database (the database must include structures for the
query to be useful). The query structure can include bond and atom properties that you specify to narrow or broaden
the list of search results. Here are two query structure examples:
Figure 11.1: Two example structure queries. A) The results will include any connected atom at the location specified
by ‘R’; B) The results will include either a single or double bond at the location specified by ‘S/D’.
To perform a query, you first draw the query structure in ChemBioDraw. You then enter the structure in a database
application such as ChemBioFinder 13.0. The application then searches one or more databases that you specify and
returns the query results.
Search limitations
Several factors determine the search results that are returned. To get the results you expect, you must first ensure
that the structure you draw accurately represents the query you want to perform. For example, if your query structure
requires that no carbon atoms in an aromatic structure can be part of any ring, you are likely to return no results or an
error, depending on the query system used.
Your search application you use can also affect your query. If the application does not accurately interpret your query
structure or the structures in the database, you may receive inaccurate results.
Generic labels
A generic label represents a nonspecific attachment. It can be either an unspecified atom, functional group, or struc-
tural feature. When you perform a query, the query will look for structures based on the type of generic label you use
and where it is in the query structure. Records that match the query structure are returned in the search results.
For example, the query structure below uses the letter ‘Q’ to indicate that a nonhydrogen, noncarbon atom must
appear at the specified location.
ChemBioDraw 13.0
Chapter 11: Query structures 197 of 401