Determination of solvation descriptors for terpene hydrocarbons from chromatographic measurements.

Gas chromatographic retention data on 107 terpene hydrocarbons from the literature together with other data have been used to obtain a set of Abraham descriptors for these 107 compounds. For 88 aliphatic cyclic terpene hydrocarbons, a fragmentation scheme was constructed that allows key descriptors to be estimated just from structure. The total set of descriptors, including those estimated by the fragmentation schemes, were then used to predict water-octanol partition coefficients for the 88 compounds, there being good agreement with values calculated from a number of well-known programs. For a small number of terpene hydrocarbons, there was good agreement between predicted and experimental values of nasal pungency thresholds, and predicted and experimental gas-blood, gas-oil, and gas-water partition coefficients. It is suggested that the descriptors obtained for the 107 terpene hydrocarbons can be used to predict water-solvent partition coefficients, gas-solvent partition coefficients, and partition coefficients in a number of biological systems.