Role of Hydrophobic Effect on the Noncovalent Interactions Between Salicylic Acid and a Series of β-Cyclodextrins

Physicochemical and Structural Characterization of Quercetin-β-Cyclodextrin Complexes

“…21 It should be noted that this reported NMR work on catechin-b-CD complex required no DMSO cosolvent because the flavonoid is water-soluble, and the close similarity in b-CD-induced proton shift changes between (þ)- catechin and quercetin would imply that the added DMSO, though capable of reducing the binding strength of the quercetin-b-CD complex in water (possibly via binding competition or quercetin extraction), will not significantly alter the basic mode of interaction. 24,25 Based on the results of NMR and stability studies, it can be inferred that the B-ring, C-ring, and at least part of the A-ring of quercetin (except C6) exhibit significant interaction with the hydrophobic b-CD cavity.…”

Characterization of permethylated β-cyclodextrin-peptide noncovalently bound complexes using electron capture dissociation mass spectrometry (ECD MS)

“…2 action. For the other basic amino-acid residue H6, if the complex was formed through an H6-CD ion-dipole interaction, uncomplexed c i + ion with i = 1-5 or [z [3][4][5][6][7] :CD] + should be formed upon ECD application. However, these fragment ions were not observed.…”

“…The ordering is c 5 Fig. 3(b), compared to [c 6 :CD] + > [c 2 :CD] + ∼ [c 5 :CD] + ∼ [c 7 :CD] + > [c 4 :CD] + > [c 8 :CD] + in Fig. 3(a).…”

“…Cyclodextrins (CDs) that consist of ␣-1-4 linked glucose units are a well-documented model system for 'host-guest' chemistry in solution (Scheme 1) [1][2][3][4][5][6][7]. Depending on the number of constituting glucose units, they are referred to as ␣(6), ␤(7), or ␥(8)-cyclodextrins.…”

“…The rims are composed of hydrophilic hydroxyl groups, whereas the outer surface and the inner cavity are hydrophobic [4]. A guest with a hydrophobic phenyl group is known to favorably include into the cavity in solution, thus forming an inclusion noncovalently bound complex [1][2][3][4][5][6][7][8]. The ability of CDs to form inclusion complexes has led to their application in separation sciences (e.g., chiral analysis) and has drawn the interest of pharmaceutical scientists in drug formulation and delivery [7][8][9][10][11].…”