CASE Ultra is an easy to use and capable QSAR software. It can automatically derive alerts from data using statistical methods or use alerts obtained using expert knowledge for predicting bioactivity of untested compounds.
CASE Ultra version 1.5.2.0 and above will support both Statistical Alert based models and Expert Rule based predictions. We have released Expert Rule Based System for predicting bacterial mutagenicity. This is in line with ICH M7 recommendation to test a chemical with two QSAR methodologies, i.e. statistical and expert rule based.
During model building, CASE Ultra mines alerts (fragments of chemical structures) that are statistically related to the activity being modeled. A CASE Ultra model is therefore a collection of relevant alerts with a detailed account of their statistical relationship with the activity. In addition, a number of physicochemical descriptors (logP, water solubility, charges, E-states, surface descriptors, etc.) are employed to build local QSARs for each alert.
When a chemical is tested with a CASE Ultra model, a search is made through all the alerts of the model to see which ones are present in the test chemical. The final prediction is based on the identified alerts and their relationship with the model’s end point.
If no positive alerts are identified in a test chemical and part of its structure is not covered by the chemical space of the model being used, the test chemical is flagged as “out of domain” for the model. This is a good way of checking if the test chemical falls within the applicability domain of the model.