Physical properties and biological activities of hesperetin and naringenin in complex with methylated β-cyclodextrin

• Waratchada Sangpheak,
• Jintawee Kicuntod,
• Roswitha Schuster,
• Thanyada Rungrotmongkol,
• Peter Wolschann,
• Nawee Kungwan,
• Helmut Viernstein,
• Monika Mueller and
• Piamsook Pongsawasdi

Beilstein J. Org. Chem. 2015, 11, 2763–2773, doi:10.3762/bjoc.11.297

• to MM energy. To correct this energy section, the same set of 25 to 80 MD snapshots was carried out by the single point DFT M062X/6-31+g (d,p) calculation in this study. The results of QM/PBSA and QM/GBSA binding free energies were in agreement with MM/PBSA and MM/GBSA energies. The experimental ∆G

• for analysis. The MM- and QM-PBSA/GBSA calculations were conducted to estimate the binding free energy of the inclusion complex [40][60]. For QM calculation, the single point M06-2X/6-31+G** level of theory including the empirical dispersion correction energy [46] was treated on the same set of

Binding mode and free energy prediction of fisetin/β-cyclodextrin inclusion complexes

• Bodee Nutho,
• Wasinee Khuntawee,
• Chompoonut Rungnim,
• Piamsook Pongsawasdi,
• Peter Wolschann,
• Alfred Karpfen,
• Nawee Kungwan and
• Thanyada Rungrotmongkol

Beilstein J. Org. Chem. 2014, 10, 2789–2799, doi:10.3762/bjoc.10.296

• binding or even unbinding preference was observed in the complexes where the larger chromone ring is located in the cavity. All MM- and QM-PBSA/GBSA free energy predictions supported the more stable fisetin/β-CD complex of the bound phenyl ring. Van der Waals interaction is the key force in forming the

• complexes. In addition, the quantum mechanics calculations with M06-2X/6-31G(d,p) clearly showed that both solvation effect and BSSE correction cannot be neglected for the energy determination of the chosen system. Keywords: cyclodextrin; fisetin; flavonoid; MM-PBSA; molecular dynamics simulation; QM-PBSA

• summation of solvation free energy, either MM-PBSA/GBSA or QM-PBSA/GBSA established the same conclusive evidence of a better formation of inclusion complexes II and III than complex I. The QM-PBSA/GBSA methods were able to predict the Gibbs free energy of the fisetin/β-CD complex comparatively close to the