TY - JOUR
T1 - NMR spectroscopic characterization of inclusion complexes of hydroxy-substituted naphthalenes with native and modified β-cyclodextrins
AU - Sueishi, Yoshimi
AU - Inazumi, Naoya
AU - Hanaya, Tadashi
PY - 2009/6
Y1 - 2009/6
N2 - The equilibrium constants (K) for the inclusion complexation of three kinds of β-cyclodextrins (β-CDs: native β-CD, heptakis(2,6-di-O- methyl)-β-CD, and 6-O-α-d-glucosyl-β-CD) with OH-substituted naphthalenes (2-naphthol, 2,3-dihydroxynaphthalene, and 2,6- dihydroxynaphthalene) were determined from the induced chemical shifts of NMR measurements for inclusion complexes: K = 188-1,250 mol-1 dm 3. The modified β-CDs form stable 1:1 inclusion complexes with OH-substituted naphthalenes, and the high stability of inclusion complexes of 2,6-dihydroxynaphthalene having a hydrophobic body and hydrophilic ends is shown. In addition, the structures of inclusion complexes were characterized by 2D ROESY NMR measurements. The differences in the structure of the inclusion complexes were observed for three kinds of naphthol guest molecules. Based on the results, the inclusion abilities enhanced by methylation of the OH groups at the CD rim or the side chain of branched β-CD are discussed.
AB - The equilibrium constants (K) for the inclusion complexation of three kinds of β-cyclodextrins (β-CDs: native β-CD, heptakis(2,6-di-O- methyl)-β-CD, and 6-O-α-d-glucosyl-β-CD) with OH-substituted naphthalenes (2-naphthol, 2,3-dihydroxynaphthalene, and 2,6- dihydroxynaphthalene) were determined from the induced chemical shifts of NMR measurements for inclusion complexes: K = 188-1,250 mol-1 dm 3. The modified β-CDs form stable 1:1 inclusion complexes with OH-substituted naphthalenes, and the high stability of inclusion complexes of 2,6-dihydroxynaphthalene having a hydrophobic body and hydrophilic ends is shown. In addition, the structures of inclusion complexes were characterized by 2D ROESY NMR measurements. The differences in the structure of the inclusion complexes were observed for three kinds of naphthol guest molecules. Based on the results, the inclusion abilities enhanced by methylation of the OH groups at the CD rim or the side chain of branched β-CD are discussed.
KW - Cyclodextrin
KW - Inclusion complex
KW - NMR
KW - Naphthols
KW - ROESY
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U2 - 10.1007/s10847-009-9545-6
DO - 10.1007/s10847-009-9545-6
M3 - Article
AN - SCOPUS:67349091096
VL - 64
SP - 135
EP - 141
JO - Journal of Inclusion Phenomena and Macrocyclic Chemistry
JF - Journal of Inclusion Phenomena and Macrocyclic Chemistry
SN - 1388-3127
IS - 1-2
ER -