The Analysis of Electronic Factors in Quantitative Structure-Activity Relationships Using Distribution Coefficients
Robert A. Scherrer, Susan Howard · ACS symposium series · 1979
In an earlier paper ( 1 ) we illustrated some of the advantages of using distribution coefficients instead of partition coefficients for the QSAR analysis of ionizable compounds. We wish to expand on one particular aspect: assessing the role electronic effects play in the manifestation of the biological activity of some compounds. Before what I say on this subject will be meaningful to you, you have to be convinced of one basic concept. That is that regression analyses in log D [and (log D) 2 if required] relate to the amount of compound at a site, or in a membrane, etc. By distribution coefficient we mean the ratio of lipid to aqueous concentration without regard to species form in the aqueous phase. The lipid phase is assumed to contain the undissociated compound. You are already familiar with log D by another name, "apparent log P," the measured log P at the pH of