Integral Sign Change Problem Check in Quantitative Structure-Activity/Property Relationships: A Tutorial

Integral Sign Change Problem Check in Quantitative Structure- Activity/Property Relationships: A Tutorial

Sign change problem (SCP) in multivariate Quantitative Structure-Activity/Property Relationships (QSAR/QSPR) is the inconsistency in the direction of association between molecular descriptors and the dependent variable. Sign change is observed when the signs of the elements of the reference vector (correlation vector for the data set obtained from variable selection) are compared to the signs o...

History of Quantitative Structure-Activity Relationships

Development of quantitative structure-pharmacokinetic relationships.

Quantitative structure-activity relationships (QSAR) relating biological activity to physiochemical descriptors have been successfully used for a number of years. It is also long recognized that pharmacokinetic parameters may play an important and even determinant role in drug action. This prompted several researchers to focus attention to pharmacokinetic parameters as potential descriptors in ...

Quantitative Structure^retention Relationships (qsrr) Inchromatography

To relate structure and chromatographic retention an approach is needed that lacks the rigour of thermodynamics but which provides otherwise inaccessible information. Such an approach is a combination of detailed models with certain thermodynamic concepts. Linear free-energy relationships (LFER) may be regarded as linear relationships between the logarithms of the rate or equilibria constants f...

Nonlinear Prediction of Quantitative Structure-Activity Relationships

Predicting the log of the partition coefficient P is a long-standing benchmark problem in Quantitative Structure-Activity Relationships (QSAR). In this paper we show that a relatively simple molecular representation (using 14 variables) can be combined with leading edge machine learning algorithms to predict logP on new compounds more accurately than existing benchmark algorithms which use comp...