Quantitative structure activity relationships, commonly called QSAR, is a branch of chemistry concerned with predicting the biological activity of molecules based on their structural properties. The word "quantitative" is pronounced /ˈkwɑːntətɪv/ with stress on the first syllable. "Structure" is pronounced /ˈstrʌktʃər/ with stress on the second syllable. "Activity" is pronounced /ækˈtɪvəti/ with stress on the second syllable. "Relationships" is pronounced /rɪˈleɪʃənʃɪps/ with stress on the second to last syllable. Together, the phrase is pronounced /ˈkwɑːntətɪv ˈstrʌktʃər ækˈtɪvəti rɪ
Quantitative Structure-Activity Relationships (QSAR) refers to a computational modeling technique used in the field of chemistry and pharmacology to predict the biological activity or property of a chemical compound based on its structural features. It is a statistical approach that correlates the physicochemical properties of a molecule with its biological activity or behavior, providing insights into the structure-activity relationship.
In QSAR, various molecular descriptors such as molecular weight, polarity, hydrophobicity, and electronic properties are calculated for a set of chemical compounds with known activities or properties. These descriptors are then associated with the corresponding experimental data through mathematical algorithms, such as multiple linear regression or artificial neural networks. The resulting QSAR model can then be used to predict the activity or property of new, untested compounds based on their structural characteristics.
QSAR models find extensive applications in drug discovery, environmental studies, toxicology, and material science, among other fields. By providing insights into the relationship between the chemical structure and the biological or physical behavior of a compound, QSAR helps guide the design and development of new drugs, identification of environmental pollutants, and evaluation of the toxicity of chemical substances.
Overall, QSAR is a valuable tool that bridges the gap between experimental and computational chemistry, offering a cost-effective and time-efficient approach to predict and understand the biological activities or properties of chemical compounds based on their structure.