Methods for Selective Modifications of Cyclodextrins.

Highly soluble cyclodextrin derivatives: chemistry, properties, and trends in development.

Publisher Summary This chapter presents a compilation of 13 C-nuclear magnetic resonance (NMR) data for oligosaccharides in the form of tables. The literature-survey presented in the chapter covers most of the data of 1982, and all of the information given had been measured for solutions in D 2 O unless stated otherwise. The data for peracetates of xylobioses and of glucobioses were recorded for solutions in CDCl 3 . All data have been copied from the original articles. For mutarotated mixtures of trisaccharides and larger oligosaccharides, the complete set of data is given for the α anomer, but only the chemical shifts for the reducing end of the anomer are given, provided that all other chemical shifts (for the remaining units) are identical. The sampling and assignment techniques used for the measurement of 13 C-NMR spectra of oligosaccharides are identical to those for monosaccharides. Particularly for oligosaccharides, it is important to measure the spectra at the same temperature—that is, with a precision better than ±0.5 p.p.m., when data are to be compared accurately.

Carbon-13 nuclear magnetic resonance data for oligosaccharides

Synthesis of chemically modified cyclodextrins

Cyclodextrins have been utilized as biomimetic models for a wide variety of processes ranging from enzymatic catalysis and membrane transport to protein ac tive-site-substrate binding interactions. As a consequence, numerous articles characterizing cyclodextrins as well as delineating their unique properties pervade the chemical literatur e.22–148 Even though the results of those studies promise great potential in terms of analytical chemistry, especially as they pertain to chromatographic separations, relatively few articles concerning their applications have been published. In view of the present inadequacy, this article is dedicated to the systematic reviewing of the use of cyclodextrins in chromatography and chemical separations. The topics to be covered include the use of cyclodextrins as selective isomeric precipitating agents, their use and role in chromatographic stationary or mobile phases, and their ability to enhance chromatographic detections. As a prerequisite to this discussion, a d...

Applications of Cyclodextrins in Chromatographic Separations and Purification Methods

The methylated analogues of s-cyclodextrin dissolve in cold water 10 – 20 times better than s-cyclodextrin itself, however, quite unusually on heating they crystallize from the solution. The structure of heptakis-(2,6-di-O-methyl)- and heptakis-(2,3,6-tri-O-methyl)-s-cyclodextrin was proved by gas-liquid chromatographic and 1H-NMR and 13C-NMR spectroscopic investigations. The corresponding model compounds were synthetized and, according to 13C-NMR spectroscopic investigations, a part of the so far published NMR assignations have to be corrected.

Synthesis and 13C‐NMR Spectroscopy of Methylated beta‐Cyclodextrins

During the enzymatic degradation of γ-cyclodextrin by Aspergillus oryzae α-amylase all of the maltooligomers from maltose to maltooctaose were detectable in the reaction mixture We have succeeded in the isolation of every single maltooligomer in pure form The qualitative and quantitative distribution of the maltooligomers were determined by HPLC during the enzymatic hydrolysis We used the maltooligomers in the enzyme kinetic investigations as both substrates and inhibitors Kinetic parameters were determined and compared in each case The application of these maltooligomers in preparative carbohydrate chemistry is in progress We can use them as the carbohydrate components of artificial antigens Other derivatives of maltooligomers, having diagnostic and enzymanalytical importance, have also been prepared

Enzymatic Degradation of Cyclodextrins; Preparation and Application of their Fragments

The ability of cyclodextrins to give inclusion or “host-guest” complexes by insertion of various organic and inorganic molecules into their hydrophobic cavity is well-known. But these cavities are remarkably rigid. We have produced a crown ether-like compound starting from beta-cyclodextrin, in which the inner cavity is enlarged and more flexible.

I. Jodál

Papers

Synthesis and 13C‐NMR Spectroscopy of Methylated beta‐Cyclodextrins

Enzymatic Degradation of Cyclodextrins; Preparation and Application of their Fragments

Preparation of macro crown ether-like compounds by the Smith degradation of cyclodextrins

Regioselective hydrogenolysis of 4,6-o-benzylidene derivatives of hexopyranosides. preparation of “glyvenol”-like compounds