The impact of β-myrcene – the main component of the hop essential oil – on the lipid films

Abstract

β-myrcene (myrcene) is the main component of the hop essential oil, the latter being a plant derived extract of a wide range of antimicrobial properties. To get a deeper insight in the role of myrcene in the membrane-related activity of the total extract, in this work the effect of this terpene on the lipid monolayers was investigated. The aim of the studies was to analyze and to compare the influence of myrcene on the one component films formed by the lipids typical of plant and fungi membranes and differing in the structure of both polar and non-polar part of the molecule. The experiments involved the surface pressure-area measurements, the penetration and the relaxation studies, Brewster angle microcopy and Grazing incidence X-ray diffraction (GIXD) studies. It was found that myrcene causes the decrease of the condensation and/or stability and changes the morphology of the lipid monolayers, however its exact effect is determined by the concentration and by the lipid type. Moreover, the mechanisms leading to the alterations within the organization of the film are different depending on the monolayer material and they may involve the extraction of the molecules from the interface and/or accommodation of terpene in the lipid environment. It was also summarized that although myrcene and the hop essential oil affect the properties of the lipid films they act on the studied membranes according to different mechanisms. • β-myrcene changes the fluidity, stability and morphology of the lipid monolayers. • β-myrcene may penetrate into the film or extract the molecules from the interface. • The mechanism of action of β-myrcene and the hop essential oil is different.