What is a Structure Activity Relationship?

Predicting biological activity from structure

Structure Activity Relationships (SAR) can be used to predict biological activity from molecular structure.  This powerful technology is used in drug discovery to guide the acquisition or synthesis of desirable new compounds, as well as to further characterize existing molecules.

The biological effects of a new chemical compound can often be predicted from its molecular structure using data about other similar compounds. This is because similar compounds may have similar physical and biological properties. There is a relationship between molecular structures and their biological activity, and this principle is referred to as Structure Activity Relationship (SAR).

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SAR tools like CDD Vault can detect correlations and build models used to evaluate new chemical structures to predict their biological activity. They can then be applied to building desirable new compounds and characterizing  them.   Existing compounds can be further evaluated using SAR for likely side-effect activities.

SAR depends on the recognition of which structural characteristics correlate with chemical and biological reactivity. Thus the ability to draw conclusions about an unknown compound depends upon both the structural features that can be characterized as well as the database of molecules against which they are compared. When combined with appropriate professional judgment, SAR can be a powerful tool to understanding functional implications when similarities are found. For example, in the case of risk assessment of uncharacterized compounds, data from the most sensitive toxicological endpoints should be included in the analysis, such as carcinogenicity or cardiotoxicity.

Figure 1 - CDD Vault displays an SAR Table showing common structural features found for molecules that have the desired biological activity.

Structure Activity Relationship is typically evaluated in a table form, called an SAR table.  SAR tables consist of the compounds, their physical properties, and activities. Experts review the table by sorting, graphing, and even scanning structural features in order to find possible relationships.

CDD Vault is a hosted cloud application that provides a full suite of research informatics tools in an intuitive, easy to use web interface. Watch a short demo video and learn more about SAR analysis using CDD Vault.