Molecular Modeling and Physicochemical Properties of Supramolecular Complexes of Limonene with α- and β-Cyclodextrins

Abstract

This study evaluated three different methods for the formation of an inclusion complex between alpha- and beta-cyclodextrin (α- and β-CD) and limonene (LIM) with the goal of improving the physicochemical properties of limonene. The study samples were prepared through physical mixing (PM), paste complexation (PC), and slurry complexation (SC) methods in the molar ratio of 1:1 (cyclodextrin:limonene). The complexes prepared were evaluated with thermogravimetry/derivate thermogravimetry, infrared spectroscopy, X-ray diffraction, complexation efficiency through gas chromatography/mass spectrometry analyses, molecular modeling, and nuclear magnetic resonance. The results showed that the physical mixing procedure did not produce complexation, but the paste and slurry methods produced inclusion complexes, which demonstrated interactions outside of the cavity of the CDs. However, the paste obtained with β-cyclodextrin did not demonstrate complexation in the gas chromatographic technique because, after extraction, most of the limonene was either surface-adsorbed by β-cyclodextrin or volatilized during the procedure. We conclude that paste complexation and slurry complexation are effective and economic methods to improve the physicochemical character of limonene and could have important applications in pharmacological activities in terms of an increase in solubility.

Bioadhesive hydrogel comprising bilirubin/β-cyclodextrin inclusion complexes promote diabetic wound healing

“…The TGA-DSC curve of β-CD was consistent with findings from previous studies ( Figure 1(D,E) ) (Dos Passos Menezes et al. 2017 ). The rapid decline in the DSC curve near 330 °C indicated the decomposition of water ( Figure 1(E) ).…”

Encapsulated Limonene: A Pleasant Lemon-Like Aroma with Promising Application in the Agri-Food Industry. A Review

“…It was observed that only partial complexation was obtained, with non-complete formation of 1:1 inclusion complexes. Limonene-β-CD complex seems to be slightly more stable than limonene-α-CD with binding energies of −4.54 kcal and −4.05 Kcal, respectively [124]. A similar trend was observed by Astray et al who determined the binding constant of limonene-(α/β)-CDs complex formation by UV-Vis technique coupled with molecular mechanics' calculations [125].…”

Bradycardic and Antiarrhythmic Effects of the D-Limonene in Rats

“…D-limonene (DL) (Figure 1), is an alcoholic monoterpene and the major constituent of the essential oil extracted from citrus species such as lemon, lime and orange. 7 Previous studies have demonstrated that DL has low toxicity and presents antioxidant, 8,9 vasodilatation, 10,11 and antihypertensive proprieties. 12 The effect of DL on the heart has not yet been elucidated and investigations into its action mechanism can provide new insights about DL and the cardiovascular system.…”