Physicochemical parameters in biological correlation analysis: meaning and limits.

Correlation analysis assumes that the physicochemical factors governing the transport, metabolism and drug-receptor interaction can be factored into hydrophobic-lipophilic component, polarizability and dispersion forces, electronic and steric effects and into indeterminate factors. Using computerized regression analysis, a generalized equation can be formulated to correlate the biological response of a set of compounds with their chemical structures in terms of physicochemical parameters of substituents. In order to explore the scope of each defined physicochemical parameter, correlations between biological effects and some combination of substituent indices are discussed.