Illustrated Glossary of Organic Chemistry

Quantitative structure-activity relationship (QSAR): A structure-activity relationship in which a drug's biological properties are quantitatively correlated with its molecular structure. The mathematical correlation is often in form of a linear equation.


QSAR equation for the biological activity of thyroid hormones: logBA =1.35πX + 1.34πY - 1.32[Y- size I] - 0.36πZ - 0.66σY,Z - 0.89D - 2.836. BA is a measure of a certain type of activity. π and σ are parameters related to the substituents X, Y, and Z.