The effect of the monocyclic monoterpene tertiary alcohol γ-terpineol on biointerfaces containing cholesterol

The compound γ-terpineol, which presents potential as microbicide and anticancer drug, was incorporated in cholesterol Langmuir monolayers, pure or mixed with DPPC. The compound expands the monolayers at higher molecular areas, but condenses them at lower areas, indicating a structural molecular rearrangement of γ-terpineol at the-water interface upon compression. Such effect was confirmed with rheological, surface potential, Brewster angle microscopy and infrared data, which indicated, respectively, reduction of the compressional modulus of the lipid monolayer, decrease of the surface potential, formation of aggregates, and alteration of the trans/gauche conformers ratio for methylene groups. Distinctive effects were observed for cholesterol monolayers without or with the presence of DPPC. Such results may help understand how the interaction of γ-terpineol with lipidic surfaces is modulated by lipids able to mediate the packing state of biointerfaces.