Analysis of Binding Energetics in Paper and Thin‐Layer Chromatography

Abstract

The binding of organic compounds to inorganic and organic polymers can be resolved by multiple regression analysis of adsorption data. Such data are provided indirectly by adsorption chromatography retentions or directly through measured heats of adsorption. This study uses chromatographic data to explore the nature of low energy binding events in terms of a primary binding descriptor (log P or MR) modified by electronic, steric, and sub‐structural descriptors. Mechanistic details are clearly revealed in the linear structure‐adsorption equations so derived. Aromatic hydrocarbons, phenols, carboxylic acids, pyridines, and other classes adsorb on silica, paper, and Nylon 6 by mechanisms that are highly sensitive to structural change and, thus, easily resolved. The descriptors clearly indicate that binding predominates over the developing solvent effect.

A new Approach to Active‐Site Binding Analysis. Inhibitors of Acetylcholinesterase

“…Binding energy then, is revealed as an additive-constitutive process which should yield to detailed analysis by a factoring procedure. In recent studies of the binding of small molecules to organic and inorganic polymers, we have found that binding is not a molecular process but rather one involving, at most, a few key positions [14]. We are encouraged by this and by Andrew's work to hope that binding to active sites may involve only a fraction of the whole molecule.…”

“…In the analysis of large sets, it is possible to define different regions of lipophilicity (rdependant) and polarizability (MR-dependant) as in a recent study of DHFR binding [6], as well as mixed behaviour in the same region [14]. Thus.…”