Thermodynamic Studies of Interactions between Sertraline Hydrochloride and Randomly Methylated β-Cyclodextrin Molecules Supported by Circular Dichroism Spectroscopy and Molecular Docking Results

Abstract

The interaction between sertraline hydrochloride (SRT) and randomly methylated β-cyclodextrin (RMβCD) molecules have been investigated at 298.15 K under atmospheric pressure. The method used—Isothermal Titration Calorimetry (ITC) enabled to determine values of the thermodynamic functions like the enthalpy (ΔH), the entropy (ΔS) and the Gibbs free energy (ΔG) of binding for the examined system. Moreover, the stoichiometry coefficient of binding (n) and binding/association constant (K) value have been calculated from the experimental results. The obtained outcome was compared with the data from the literature for other non-ionic βCD derivatives interacting with SRT and the enthalpy-entropy compensation were observed and interpreted. Furthermore, the connection of RMβCD with SRT was characterized by circular dichroism spectroscopy (CD) and complexes of βCD derivatives with SRT were characterized through the computational studies with the use of molecular docking (MD).

Primary vs secondary: Directionalized guest coordination in β-cyclodextrin derivatives

“…As a result, in computational investigations of host-guest coordinations, there is a tendency to simplify the modelling procedure by neglecting conformational flexibility and considering only a single binding mode. [11][12][13][14][15][16][17][18] As a result, the computational inspection of host-guest binding is simplified to a singlestate calculation that can be treated via single-point calculations with normal mode approximation or restrained sampling in the neighborhood of the initial bound configuration. However, recent modelling reports with comprehensive conformational sampling suggest the pivotal role of the conformational flexibility of both components involved in host-guest coordination and a general multi-modal binding behavior in host-guest complexes, [19][20][21][22][23] which suggests that the single-state approximation, regardless of the accuracy level of the employed Hamiltonian, could introduce systematic biases of unknown magnitude.…”

Sulfobutylation of Beta-Cyclodextrin Enhances the Complex Formation with Mitragynine: An NMR and Chiroptical Study

“…Therefore, achiral guest molecules often show induced CD signals around their UV/Visible absorption bands upon encapsulation within the CyD cavity [ 39 , 40 , 41 ]. In addition, the intrinsic CD pattern of chiral compounds may be modified on inclusion due to conformational adaptation and/or interaction of their electronic transition dipoles with those of the σ-bonds of D-glucosyl units [ 42 , 43 , 44 ]. Accordingly, it is reasonable to think that CyD binding of MTR generates some CD spectral alterations.…”

“…However, at an angle of about 30–40° between the direction of the transition moment and the symmetry axis, contributions of the different oscillator pairs cancel each other out and thus no CD activity can be measured. In the case of inclusion complexes of chiral compounds, the CEs induced by this mechanism are superimposed on the intrinsic CD signals of the guest, rendering them stronger or weaker [ 42 , 44 ]. Upon increase in SBEβCyD concentration in the MTR solution, the magnitude of the negative CE at 216 nm reduced by about 30% ( Figure 7 A).…”

β‐Cyclodextrin and folic acid host–guest interaction binding parameters determined by Taylor dispersion analysis and affinity capillary electrophoresis

“…To improve the solubility, stability, and bioavailability of FA, β-CD complex in water has been investigated using electrospray ionization mass spectrometry, isothermal titration calorimetry (ITC), and nuclear magnetic resonance spectrometry [17]. Circular dichroism spectroscopy [18], fluorescence spectroscopy [19][20][21], ITC [22,23], and molecular docking simulation [24][25][26] have been used to study interactions between CDs and other drug molecules. It is noted that the in-depth characterization of CD-drug complexes for drug development is improved by developing new analytical tools.…”