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The aim of this study was to obtain solid carvacrol-cyclodextrin (CD) complexes for use in the pharmaceutical industry. To this end, the complexation of carvacrol at different pH values was studied in detail, to determine the type of CD and the reaction environment that supported the highest amount of encapsulated carvacrol. Evidence of the capability of hydroxypropyl-β-cyclodextrins (HP-β-CD) to form inclusion complexes with carvacrol (KC = 5042 ± 176 L mol−1) and more high complexation efficiency (2.824) was demonstrated for HP-β-CDs using two different energy sources, ultrasound (US) (KC = 8129 ± 194 L mol−1 24 h) and microwave irradiation (MWI) (KC = 6909 ± 161 L mol−1), followed by spraying the resulting solution in a spray dryer. To confirm complex formation, the complexes were characterized using various instrumental methods to corroborate the carvacrol incorporation into the hydrophobic cavity of HP-β-CD. The obtained carvacrol solid complexes were analyzed by 1H nuclear magnetic resonance (1H-NMR) and 2D nuclear magnetic resonance (ROSEY), differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR) characterization. The structures of the resulting complexes were also characterized by molecular modeling. Furthermore, 1 mM HP-β-CD-carvacrol complex has been shown to reduce cell proliferation in HCT-116 colorectal cancer cells by 43%, much more than in a healthy lung fibroblast MRC-5 cell line (11%). [ABSTRACT FROM AUTHOR]

In the present work, the nematic glassy state of the non-symmetric LC dimer α-(4-cyanobiphenyl-4′-yloxy)-ω-(1-pyrenimine-benzylidene-4′-oxy) undecane is studied by means of calorimetric and dielectric measurements. The most striking result of the work is the presence of two different glass transition temperatures: one due to the freezing of the flip-flop motions of the bulkier unit of the dimer and the other, at a lower temperature, related to the freezing of the flip-flop and precessional motions of the cyanobiphenyl unit. This result shows the fact that glass transition is the consequence of the freezing of one or more coupled dynamic disorders and not of the disordered phase itself. In order to avoid crystallization when the bulk sample is cooled down, the LC dimer has been confined via the dispersion of γ-alumina nanoparticles, in several concentrations. [ABSTRACT FROM AUTHOR]

The objective of the present study is to obtain linalool- cyclodextrin (CDs) solid complexes for possible applications in the food industry. For this purpose, a detailed study of linalool complexation was carried out at different pH values, to optimize the type of CDs and reaction medium that support the highest quantity of encapsulated linalool. Once demonstrated the ability of hydroxypropyl-β-cyclodextrin (HP-β-CDs), to form inclusion complexes with linalool (KC = 921 ± 21 L mol−1) and given their greater complexation efficacy (6.788) at neutral pH, HP-β-CDs were selected to produce solid inclusion complexes by using two different energy sources, ultrasounds and microwave irradiation, subsequently spraying the solutions obtained in the Spray Dryer. To provide scientific solidity to the experimental results, the complexes obtained were characterized by using different instrumental techniques in order to confirm the inclusion of linalool in the HP-β-CDs hydrophobic cavity. The linalool solid complexes obtained were characterized by using 1H nuclear magnetic resonance (1H-NMR) and 2D nuclear magnetic resonance (ROSEY), differential scanning calorimetry, thermogravimetry and Fourier transform infrared spectrometry. Moreover, the structure of the complex obtained were also characterized by molecular modeling. [ABSTRACT FROM AUTHOR]