Inclusion interactions and molecular microcapsule of Salvia sclarea L. essential oil with beta-cyclodextrin derivatives

摘要

The inclusion interactions of beta-cyclodextrin (beta-CD), heptakis (2,6-di-methyl)-beta-CD (DM-beta-CD), mono[2-O-(2-hydroxyethyl)]-beta-CD (2-HE-beta-CD), and mono[2-O-(2-hydro-xypropyl)]-beta-CD (2-HP-beta-CD) with Salvia sclarea L. essential oil (SEO) were investigated by spectrofluorimetry, and the various factors affecting the inclusion process were examined in detail. At the same time, the formation constants at different temperatures and the thermodynamic parameters (triangle openH, triangleopenS and triangle openG) were calculated. The molecular microcapsule of SEO with beta-CD was prepared by the method of saturated aqueous solution, and the stability of the microcapsule was determined. The results suggest that the stoichiometry of the SEO–CDs inclusion complexes was 1:1 (molar ratio), the formation constants of CDs with SEO decreased with the increasing of temperature, and the order that the capability associated with SEO was beta-CD > DM-beta-CD > 2-HE-beta-CD > 2-HP-beta-CD. The thermodynamic measurements showed that the inclusion process was an exothermic and enthalpy-driven process accompanied with a negative entropic contribution, and Van der Waals force plays an importance role in the process. In addition, the content of SEO inthe microcapsule was 0.14 g/g and its stabilization was obviously improved.