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ChemSAR Properties - Serving Property Information
Now that chemical database technology
is well developed, research organizations routinely maintain databases of chemicals bought and
synthesized. Built on these databases are applications such as e-commerce procurement, inventory
management and chemical registration. Many organizations have implemented these applications
using chemical webserver technology such as ChemOffice WebServer. Now a new application has come
to light for estimating, storing and serving chemical property data over the same Internet or
intranet links that carry the other applications. This newest ChemOffice WebServer application
is called ChemSAR Properties. Property information adds greatly to the value of a chemical record.
While it is good to know whether your organization has bought or synthesized a certain chemical,
it is even better to know its physical properties. An interesting side-application of a chemical
registration system would be to estimate, calculate, or store properties when the chemical is
registered.
- Web based application that delivers computed, estimated, orated properties for specified
lists of compounds on demand
- Different computational engines can be easily configured to deliver the computed
properties
- Large jobs can be diverted to network computational resources, freeing desktop workstations
and services
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Properties on Demand
Properties can also be computed as needed. For example, a scientist
might perform a substructure search on a large database to obtain all the compounds containing
a pharmacophore of interest. Then, the scientist could choose desired properties from a checklist,
and request a report in which these properties are tabulated for each of the compounds found
by the substructure search. Properties can be obtained, computed or estimated from databases
in a variety of ways. Some properties are only a function of the formula and shape of a molecule.
For example, molecular moments, surface area, volume, number of possible donors/acceptors, and
so on. Many physical properties like boiling point, vapor pressure, and logP, can be estimated
using a variety of methodologies. Other properties that are based on the electronic structure
of the molecule may require semiempirical or ab initio calculations. Examples of this group are
dipole moments and higher electrostatic moments, and data based on molecular orbital levels,
such as the separation between the highest occupied and lowest unoccupied orbitals (the LUMO-HOMO
gap). Within ChemOffice WebServer there are a number of applications that can supply the requested
properties. Estimation techniques such as CLogP are well known. The Chem3D program provides molecular
mechanics to produce energy-minimized structures, and also includes the Connolly surface and
volume applications. Chem3D can also perform MOPAC calculations to obtain electronic properties
and geometry optimizations at the semiempirical molecular orbital level. And finally, Chem3D
has interfaces to Gaussian and GAMESS for higher-level electronic structure calculations.
Spreadsheet Properties
Depending on which properties the scientist wants, and the
precision required, filling out the property table for a long list of molecules could be a time-consuming
job. With ChemSAR Properties, the job can be dispatched to computational resources in the network,
and the scientist is notified when the results are ready. A convenient way to return the results
is a spreadsheet using the desktop ChemSAR/Excel version. This way the chemical names, structures
and properties are all neatly tabulated for future use when performing simple statistics or exploring
structure-activity relationships. |
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