Acid dissociation of cyclohexaamylose and cycloheptaamylose

Gelb, Robert I.; Schwartz, Lowell M.; Bradshaw, John J.; Laufer, Daniel A.

doi:10.1016/0045-2068(80)90039-5

Cited by 89 publications

(37 citation statements)

References 15 publications

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“…1d. Since the pK a value of γ -CD is 12.1 [38], nearly all hydroxyl groups of γ -CD molecule are changed to negative oxygenic ions at pH 13.5, and thus hydrogen bonding between neighboring γ -CD units in the DPB-γ -CD nanotube becomes ineffective leading to the collapse of the nanotubular structure. It is also observed that the mean hydrodynamic radius of the aggregated γ -CD decreases.…”

Section: Dls Analysismentioning

confidence: 99%

Investigation on γ-cyclodextrin nanotube induced by -diphenylbenzidine molecule

Shen

2006

Journal of Colloid and Interface Science

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Section: Dls Analysismentioning

confidence: 99%

Investigation on γ-cyclodextrin nanotube induced by -diphenylbenzidine molecule

Shen

2006

Journal of Colloid and Interface Science

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“…Considering that the pKa values for a-CD, b-CD and g-CD are 12.33, 12.20 and 12.08, respectively (31)(32)(33), it is proposed that the reaction mechanism is shown in Scheme 2 for the hydrolysis of CF with OH 2 in the presence of CDs. The rate constant observed (k obs ) according to the reaction mechanism shown in Scheme 2 is the following Equation (3):…”

Section: Resultsmentioning

confidence: 99%

Basic hydrolysis of carbofuran in the presence of cyclodextrins

Morales

Manso

Mejuto

2012

Supramolecular Chemistry

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“…The pKa of secondary hydroxyl groups has been reported to be 12.08-12.33. 20,21 An upfieldshift was also observed at pH values 412, probably due to the dissociation of secondary hydroxyl groups. The pH at the end point of titration was about 10.…”

Section: A-amino-3a-deoxy-(2as3as)-cyclodextrins K Takahashi Et Almentioning

confidence: 91%

“…The chemical shifts of the H1 and H4 protons and C1 and C4 carbons are known to reflect the conformation around the glycosidic bonds. [20][21][22] A change in the observed 13 C chemical shift of ca. 2 p.p.m.…”

Section: A-amino-3a-deoxy-(2as3as)-cyclodextrins K Takahashi Et Almentioning

confidence: 99%

Characterization and structural determination of 3A-amino-3A-deoxy-(2AS, 3AS)-cyclodextrins by NMR spectroscopy

Takahashi

Andou

Fujiwara

2012

Polym J

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The proton and carbon nuclear magnetic resonance (NMR) resonances have been assigned for 3A-amino-3A-deoxy-(2AS,3AS)-a-, b-and c-cyclodextrins (CyDs) (3a, 3b and 3c). In these CyDs, a glucose residue has been replaced by an altro-pyranose unit with an axial hydroxyl group. Assignments were made with one-dimensional NMR and COSY, TOCSY, ROESY and CHSHF (heteronuclear shift correlation) spectra. Titration by NMR shift changes gave amino-group pK a values of 7.73 and 8.84 for 3b and 6A-amino-6A-deoxy-b-CyD (6b), respectively. Polymer Journal ( Keywords: altro-cyclodextrin; hydrogen bonding; NMR; structural assignment; titration INTRODUCTIONCarbohydrates are key recognition elements in biological processes. However, in most cases, the role of carbohydrates and the detailed mechanisms of these events are still poorly understood. It seems that a clear model of the structure of carbohydrates is very important for understanding the role of carbohydrates in these processes. Carbohydrates look much simpler than other biomolecules as they differ from each other mainly by stereochemistry. However, carbohydrates actually have much more information capacity than proteins because they vary by linkages and stereochemistry and can be branched. The structure determination of complex oligosaccharides involves discovering the primary structure, stereochemistry, sequence, linkages and anomeric configurations; thus, it is actually a very challenging problem.Cyclodextrins (CyDs) are naturally occurring cyclic carbohydrates consisting of 6-8 glucopyranosyl residues linked by a-1,4 glycosidic bonds. They have a hydrophobic cavity and form inclusion complexes with various guest molecules in aqueous solution and solid state.

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Acid dissociation of cyclohexaamylose and cycloheptaamylose

Cited by 89 publications

References 15 publications

Investigation on γ-cyclodextrin nanotube induced by -diphenylbenzidine molecule

Investigation on γ-cyclodextrin nanotube induced by -diphenylbenzidine molecule

Basic hydrolysis of carbofuran in the presence of cyclodextrins

Characterization and structural determination of 3A-amino-3A-deoxy-(2AS, 3AS)-cyclodextrins by NMR spectroscopy

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