Reversed phase chromatographic study of the inclusion selectivity of terpene derivatives with beta-cyclodextrin in water cosolvent mixtures

Terpene compounds include a wide variety of molecules with very different s tructures and physico-chemical properties. Monoterpenes are of interest bec ause of their volatility and aromatic properties. Inclusion complexation of these molecules with cyclodextrins will lead to chemical and volatility pr otection and to a possible controlled release. In this study, reversed phas e liquid chromatography was used to demonstrate that some terpenes can form inclusion complexes with beta-cyclodextrin. The stability of these complex es was studied for aromatic, aliphatic, or acyclic terpenes with various mo bile phases. It is confirmed that mobile phase composition plays a major role in the com plex stability. Moreover, in terms of separation, it was observed that mobi le phase characteristics could modify inclusion selectivity, with retention inversions for some terpene derivatives when beta-cyclodextrin was added t o the mobile phase. It was also demonstrated that "rough" molecular modelli ng can qualitatively predict stoichiometry and relative stability of the fo rmed inclusion complexes.