Characterization of Cyclodextrin/Volatile Inclusion Complexes: A Review

Abstract

Cyclodextrins (CDs) are a family of cyclic oligosaccharides that constitute one of the most widely used molecular hosts in supramolecular chemistry. Encapsulation in the hydrophobic cavity of CDs positively affects the physical and chemical characteristics of the guests upon the formation of inclusion complexes. Such a property is interestingly employed to retain volatile guests and reduce their volatility. Within this scope, the starting crucial point for a suitable and careful characterization of an inclusion complex is to assess the value of the formation constant (Kf), also called stability or binding constant. This task requires the application of the appropriate analytical method and technique. Thus, the aim of the present paper is to give a general overview of the main analytical tools used for the determination of Kf values for CD/volatile inclusion complexes. This review emphasizes on the advantages, inconvenients and limits of each applied method. A special attention is also dedicated to the improvement of the current methods and to the development of new techniques. Further, the applicability of each technique is illustrated by a summary of data obtained from the literature.

Do Cyclodextrins Encapsulate Volatiles in Deep Eutectic Systems?

“…It is not only possible to directly probe the genuine inclusion of the guest in the CD cavity, but the large number of spectral parameters that can be measured and analysed give also access to unique qualitative and quantitative information. 7,9,[27][28][29][30] In the present work, we demonstrate that the measurement of different NMR parameters is extremely beneficial to investigate the sorption behaviour of βCD towards selected VOC in the DES reline (see Fig. 1 for structures).…”

Electrospinning of Essential Oils

“…In most works, complexes of cinnamon EO and cyclodextrins were processed. Cyclodextrins are natural cyclic oligosaccharides with a truncated cone shape characterised by a hydrophilic external surface and a hydrophobic interior cavity (Figure 2a) [26,75,76]. They are extensively used to form inclusion complexes with essential oils, which are trapped in the hydrophobic cavity, in order to improve EOs bioavailability and stability.…”

Fluorescence-Based Detection of Benzene, Toluene, Ethylbenzene, Xylene, and Cumene (BTEXC) Compounds in Fuel-Contaminated Snow Environments

“…These results demonstrate that the fluorescence emission was influenced by the sample matrix and cyclodextrin identity, which in turn affects the interactions of the fluorophore with the aromatic analytes investigated (Figure 7). The fluorescence modulation ratios in the presence of cyclodextrin increased only slightly due to attenuated interactions between the fluorophore and analyte, as noted by the low binding-constant values (Table 2) [58,59]. These slight increases can be attributed to the competitive binding with longchain alkanes.…”