Theoretical and Experimental Studies on Inclusion Complexes of Pinostrobin and β-Cyclodextrins

Abstract

Pinostrobin (PNS) belongs to the flavanone subclass of flavonoids which shows several biological activities such as anti-inflammatory, anti-cancerogenic, anti-viral and anti-oxidative effects. Similar to other flavonoids, PNS has a quite low water solubility. The purpose of this work is to improve the solubility and the biological activities of PNS by forming inclusion complexes with β-cyclodextrin (βCD) and its derivatives, heptakis-(2,6-di-O-methyl)-β-cyclodextrin (2,6-DMβCD) and (2-hydroxypropyl)-β-cyclodextrin (HPβCD). The AL-type diagram of the phase solubility studies of PNS exhibited the formed inclusion complexes with the 1:1 molar ratio. Inclusion complexes were prepared by the freeze-drying method and were characterized by differential scanning calorimetry (DSC). Two-dimensional nuclear magnetic resonance (2D-NMR) and steered molecular dynamics (SMD) simulation revealed two different binding modes of PNS, i.e., its phenyl- (P-PNS) and chromone- (C-PNS) rings preferably inserted into the cavity of βCD derivatives whilst only one orientation of PNS, where the C-PNS ring is inside the cavity, was detected in the case of the parental βCD. All PNS/βCDs complexes had a higher dissolution rate than free PNS. Both PNS and its complexes significantly exerted a lowering effect on the IL-6 secretion in LPS-stimulated macrophages and showed a moderate cytotoxic effect against MCF-7 and HeLa cancer cell lines in vitro.

Comparative Evaluation for Controlled Release of Amoxicillin from RSM-CCD-Optimized Nanocomposites Based on Sodium Alginate and Chitosan-Containing Inclusion Complexes

“…After reaching equilibrium, the concentration of AMX was measured spectrophotometrically using a UV–visible (double-beam) spectrophotometer and compared to a calibration plot using absorbance at λ max = 225.4 nm. Using the following equation, the apparent stability constant K s was determined from the graph of phase solubility where S o is the initial solubility of AMX and K s is the apparent stability constant.…”

Nepafenac-Loaded Cyclodextrin/Polymer Nanoaggregates: A New Approach to Eye Drop Formulation

“…Samples were prepared using a freeze drying method [53,54]. Clear supernatant solutions from phase solubility studies of γCD and HPβCD that had shown A l -type profiles were used to confirm the presence of nepafenac/CDs complexes.…”

Enhanced Solubility and Anticancer Potential of Mansonone G By β-Cyclodextrin-Based Host-Guest Complexation: A Computational and Experimental Study

“…The MβCD (e.g., 2,6-di- O -methyl-βCD; DMβCD) and the HPβCD derivatives exhibit higher aqueous solubility and lower toxicity than the unmodified βCD [21,22,23]. Several experimental and theoretical reports (both classical molecular dynamics (MD) and density functional theory (DFT)) have demonstrated that the water solubility, chemical stability, and anticancer activity of poorly soluble molecules are significantly improved by complexation with DMβCD and HPβCD derivatives [24,25,26,27,28]. However, the information on the inclusion complexes of MG with βCDs has never been previously reported.…”