Capped cyclodextrin

Tabushi, Iwao; Shimokawa, Kazuhiro; Shimizu, Nobuaki; Shirakata, Hiroko; Fujita, Kahee

doi:10.1021/ja00440a083

Cited by 159 publications

(47 citation statements)

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“…a 0.2 M phosphate buffer of pH 11.6. 'Earlier workers (17,20,23) obtained values of 2.0, 1.4, and 2.2 mM, using similar methods based on the displacement of the ANS.…”

Section: Discussionmentioning

confidence: 92%

See 1 more Smart Citation

Dissociation constants of host–guest complexes of alkyl-bearing compounds with β-cyclodextrin and "hydroxypropyl-β-cyclodextrin"

Tee¹,

Gadosy²,

Giorgi³

1996

Can. J. Chem.

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Dissociation constants (Kd) of host-guest complexes formed from P-cyclodextrin or "hydroxypropyl-P-cyclodextrin" (P-CD and Hp-P-CD) and several types of aliphatic guests (alcohols, alkanesulfonate ions, alkylamines, and a-amino acids), with up to eight carbons in a chain, are reported. These constants were determined by inhibition kinetics and by a spectrofluorometric displacement method based on competition with 1-anilino-8-naphthalenesulfonate ion as a fluorescent probe. The value of Kd for a particular amine is close to that for the corresponding alcohol. For linear alkyl derivatives, there are strong correlations between pK, (= -log Kd) and the chain length of the guest, with slopes around 0.5, complementing trends that were noted earlier. Furthermore, the strengths of binding of various aliphatic derivatives to P-CD and to Hp-P-CD are close, with Kd values for the two CDs usually being within a factor of 2 of each other. Overall, for the binding of over 50 alkyl-bearing derivatives, there is a good correlation of pKd for Hp-P-CD with that for P-CD, with unit slope. These observations imply that the binding of simple aliphatic guests to Hp-P-CD is not greatly influenced by the modification of the hydroxyl groups on the primary side of the P-CD cavity but this may not be true for longer aliphatic derivatives (>Cx) or for aromatics that penetrate farther into the CD cavity.

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“…a 0.2 M phosphate buffer of pH 11.6. 'Earlier workers (17,20,23) obtained values of 2.0, 1.4, and 2.2 mM, using similar methods based on the displacement of the ANS.…”

Section: Discussionmentioning

confidence: 92%

“…To determine dissociation constants of amineCD complexes we used competition between the amines and the fluorescent probe ANS for the CD (17)(18)(19)(20)(21)(22)(23). First, dissociation constants (KANS) for the CD.ANS complexes were determined in a basic solution, the same as that to be used with the amines.…”

Section: Methodsmentioning

confidence: 99%

Dissociation constants of host–guest complexes of alkyl-bearing compounds with β-cyclodextrin and "hydroxypropyl-β-cyclodextrin"

Tee¹,

Gadosy²,

Giorgi³

1996

Can. J. Chem.

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“…The constant lfn denotes the minimum number of structural units required to bind a solute molecule and K is the intrinsic binding constant, while the product Kn is the first binding constant As shown in Figure 3, the plot of [2] 12 although polymers containing /3-cyclodextrin as pendant groups were superior. 13 Needless to say, these cyclodextrins each have an inclusion cavity of hydrophobic character, but 2 does not.…”

Section: Resultsmentioning

confidence: 99%

Binding of Organic Solutes to a Polymer Containing Pendant Sugar Groups

Kobayashi

Sumitomo

1981

Polym J

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Polymers conta;mng sugars as pendant groups are receiving a growing amount of attention because of the possibility for their use in a wide range of applications for which natural polysaccharides are not suitable. Several types of sugar-containing polymers have been developed in order to make use of hydrophilicity/· 2 chirality,3.4 and biological activity 5 · 6 of sugars. From this standpoint, we synthesized an amphiphilic polymer 2, from glucose and chloromethylstyrene as starting materials. 7 The 2 Scheme solution properties of 2 suggested that it behaved as a nonionic polysoap in water, and a spectrophotometric investigation showed that an organic solute such as methyl orange was strongly bound to the hydrophobic regions of 2 in water.The present study was undertaken in order to confirm the solute binding properties of 2 using magnesium 1-anilino-8-naphthalenesulfonate (ANS) as the organic solute. ANS has been used extensively as a hydrophobic probe, that is nonfluorescent in water but becomes highly fluorescent on binding to non-polar regions in proteins, 8 • 9 biomembranes, 10 cyclodextrins, 11 -13 and synthetic polymers. 14 The ANS binding constants of 2 were determined and compared with those of analogs. EXPERIMENTALPolymer 2 used was prepared from its precursor 1 with a number-average degree of polymerization of 420. 7 . ANS, supplied by Nakarai Chemicals, Ltd., was recrystallized twice from hot water. Fluorescence spectra were recorded with a JASCO FP-550 spectrofluorometer at room temperature. The excitation wavelength was 380 nm and both the excitation and emission slits were set at 10 nm. RESULTS AND DISCUSSIONFigure 1 depicts fluorescence emission spectra of ANS in the absence and presence of the polymer 2. Fluorescence of ANS alone was negligible, but 2 induced a striking enhancement of the fluorescence.Simultaneously, the emission maximum A.:;,., also blue-shifted; it decreased abruptly with increasing polymer concentrations and took on a constant value (475 nm) at polymer concentrations higher than 10-3 M. The large blue shift by 50nm on binding to 2 indicates that the bound ANS remained in a hydrophobic microenvironment. It is suggested that the emission maximum of the adsorb-517

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“…This relatively simple problem of regioselectivity, namely getting a single product out of 14, which could otherwise be separated 23 , has been the prime challenge in this area for the past few decades. In the field of CDs, seminal work by Tabushi and Knowles paved the way to compounds with two 24 or three 25 identical functions in the 1970s and developed in the next 30 years 20,21 , but heterofunctionalization of CDs was only accomplished after difficult separation of mixtures of regioisomers 26,27 . It is only recently that strategies to get concave molecules with more than two different functions emerged.…”

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confidence: 99%

Site-selective hexa-hetero-functionalization of α-cyclodextrin an archetypical C6-symmetric concave cycle

et al. 2014

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Access to C n (n44) symmetric cyclic concave molecules with a different function on each of their n subunits is an unmet challenge. The reason lies in the lack of a post-functionalization method whose site selectivity is sufficiently understood, predictable and modulable to access most functionalization patterns. Here we disclose a new site-directing rule for a debenzylation reaction on cyclodextrins that solves this problem and allows the unprecedented access to penta-and ultimately hexa-differentiations of such C 6 concave cycles. This achievement opens the access to objects with very high-density information.

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Capped cyclodextrin

Cited by 159 publications

References 0 publications

Dissociation constants of host–guest complexes of alkyl-bearing compounds with β-cyclodextrin and "hydroxypropyl-β-cyclodextrin"

Dissociation constants of host–guest complexes of alkyl-bearing compounds with β-cyclodextrin and "hydroxypropyl-β-cyclodextrin"

Binding of Organic Solutes to a Polymer Containing Pendant Sugar Groups

Site-selective hexa-hetero-functionalization of α-cyclodextrin an archetypical C6-symmetric concave cycle

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