What is SAR analysis?

Structural Analysis Relationship (SAR) analysis is the evaluation of the relationship between the structure of chemical compounds, of interest to medicine, to their biological functions in the body. SAR analysis is especially significant in drug development since it enables the discovery of novel drugs to treat diseases.

Molecular compounds with the same core functional groups, such as, for example, the benzene double rings in antibiotics, gives them more or less similar biological function. Such molecular compounds work by binding specific active sites in target biological molecules such as receptors of cells leading to a conformational change of the latter. Such conformational change alters some biological function in the biological pathway that the target molecule is involved.

These molecular compounds can then be tweaked by removing or addition of chemical ligands to modify their chemistry and hence also affect their function in the body. Several modified molecules also called hits in drug discovery, are then analyzed using bioinformatics tools and then by biological experiments such as microarrays, to ascertain a lead compound. The lead compound is then further modified to achieve the best-desired properties and the final compound is then used in making drugs.

Usually, finding potent molecular/chemical compounds for a particular biological function, data mining in biological databases is conducted and hits are then analyzed using bioinformatics tools to reach a lead compound. The function of these structural hits can even be predicted by analyzing their structure and comparing them to other known compounds of similar structure or functional groups. Experiments are then performed to validate what was postulated. Experiments are significant since they enable scientists to ascertain aspects such as thermodynamics, pharmacokinetics, side effects/toxicity, stereochemistry, and elimination of the compounds.

Today, novel chemical compounds can be drawn on computers using computer models that work on data from biological databases. These novel compounds can then be synthesized, from scratch, and analyzed.