Substitution in .beta.-cyclodextrin directed by basicity: preparation of 2-O- and 6-O-[(R)- and (S)-2-hydroxypropyl] derivatives

Rao, C. Trinadha; Lindberg, Bengt; Lindberg, J. Johan; Pitha, Josef

doi:10.1021/jo00003a082

Cited by 63 publications

(19 citation statements)

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“…Figure 10 shows the 1 H-NMR spectra of the molecular tube in D 2 O and in DMSO-d 6 . The 1 H-NMR spectra show that peaks of the glucose units of ␣-CD, the protons of the bridge, and H 1 proton of ␣-CD with the bridge [18] can be observed. By comparing the 1 H-NMR spectra with that of 1,3-diethoxy-2-propanol, a model compound of the bridge of MT, it is known that the signals of H a and H b of the bridge overlap with those of ␣-CD.…”

Section: Scheme 2 the Preparation Of Molecular Tubes (Mt)mentioning

confidence: 99%

Molecular Recognition: Preparation of Polyrotaxan and Tubular Polymer from Cyclodextrin

Harada

Kamachi

1997

Polym. Adv. Technol.

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Section: Scheme 2 the Preparation Of Molecular Tubes (Mt)mentioning

confidence: 99%

Molecular Recognition: Preparation of Polyrotaxan and Tubular Polymer from Cyclodextrin

Harada

Kamachi

1997

Polym. Adv. Technol.

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“…A downfield shift of H-1 for about 0.14 ppm effected by 2-O-substitution allows to estimate the partial DS in this position (x 2 ), while the total DS can be calculated from the ratio of a substituent signal, e. g. of CH 3 in hydroxypropyl (HP) or in quaternary ammonium groups, to the summarized H-1 signals. [18,19] Degradation to monomers, chromatography and mass spectrometry Liquid Chromatography: While NMR experiments predominantly supply the partial DS values x i , hydrolysis and HPLC analysis can complete this information, provided the substituents are stable under the acidic conditions applied (most of the ethers). Separation of the un-, mono-, di-and trisubstituted glucose fractions c 0 , c 1 , c 2 , and c 3 , can easily be achieved due to differences in mass and polarity.…”

Section: Nmr Spectroscopymentioning

confidence: 99%

Structure analysis of 1,4-glucan derivatives

Mischnick

Heinrich

Gohdes

et al. 2000

Macromol. Chem. Phys.

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Cellulose, starch and cyclodextrin ethers and esters are produced for many fields of application as for example oil recovery, building and ceramic materials, textile and paper industry, food, cosmetics, and pharmaceuticals. For further development of new types of derivatives and also for a better understanding of their properties a detailed analysis of the usually complex mixtures is required. By complete degradation, separation and quantification of appropriate monomer derivatives the regioselectivity in the glucose unit can be determined. For the determination of the substitution pattern in the polymer chain partial random degradation, oligomer analysis by mass spectrometry, and subsequent statistical evaluation can be applied. The composition of products obtained by enzymatic degradation also reflects the pattern in the polymer chain. In addition a possible heterogeneity of the material must be taken into consideration, since any degradation averages the structural information.

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“…There are no cyclodextrin (CD) derivates with less than six glucopyranose units (Marques, ). HPβCD is derived from beta‐cyclodextrins (βCD) using propylene oxide and its water solubility is much higher than that of βCD (Rao, Lindberg, Lindberg, & Pitha, ).…”

Section: Introductionmentioning

confidence: 99%

Encapsulation of clove essential oil in hydroxypropyl beta-cyclodextrin for characterization, controlled release, and antioxidant activity

Babaoğlu

Bayrak

Özdemır

et al. 2017

Journal of Food Processing and Preservation

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The aim of this study was to investigate the physicochemical characteristics, release behavior, and antioxidant activity of clove essential oil‐hydroxypropyl beta‐cyclodextrin (CEO‐HPβCD) inclusion complexes. Clove essential oil was encapsulated by the kneading method with hydroxypropyl beta‐cyclodextrin in a 1:1 molecular ratio. The entrapment efficiency of the encapsulated particles was 97.04% ± 1.57. The average particle size was 165.87 ± 1.65 nm and polydispersity index was .25 ± .03. In vitro release profile of CEO‐HPβCD inclusion complexes indicated slow and sustained release. DPPH scavenging activity of free clove essential oil and encapsulated particles was 25.20% ± 1.02 and 28.70% ± .77, respectively. Total phenolic content of free clove essential oil was 18.59 ± 1.60 mg GAE/100 mg oil while total phenolic content of particles was 22.57 ± 1.48 mg GAE/100 mg oil. The results of the study revealed that using hydroxypropyl beta‐cyclodextrin to encapsulate clove essential oil can be beneficial for the food and pharmaceutical industries. Practical applications Clove essential oil has many biological activities due to its major compound eugenol. Choosing the appropriate method is a significant step for keeping active constituents. Encapsulation that is a beneficial process to control of the bioactive components can prevent degradation and loss of active compounds and prolong the shelf life of entrapped materials. This study can lead to use kneading method which is a low cost and easy encapsulation technique, for conservation of volatile active components, so these compounds can be used more intensely in the form of powder.

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Substitution in .beta.-cyclodextrin directed by basicity: preparation of 2-O- and 6-O-[(R)- and (S)-2-hydroxypropyl] derivatives

Cited by 63 publications

References 0 publications

Molecular Recognition: Preparation of Polyrotaxan and Tubular Polymer from Cyclodextrin

Molecular Recognition: Preparation of Polyrotaxan and Tubular Polymer from Cyclodextrin

Structure analysis of 1,4-glucan derivatives

Encapsulation of clove essential oil in hydroxypropyl beta-cyclodextrin for characterization, controlled release, and antioxidant activity

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