Cyclodextrin derivatives, for

Bicchi C, ArtufFo G, D Amato A, Manzin V, Galli A, Galli M, Cyclodextrin derivatives for the GC separation of racemic mixtures of volatile compotmds, Part VI The influence of the diluting phase on the enantioselectivity of 2,6-di-O-methyl-3-O-pentyl-fi-cyclodextrin, /Resolut Chromatogr 16 209—214, 1993. 

In analogy to the carboxylate binding by zinc-containing cyclodextrin 10 (see Sect. 2), Lewis acidic centers such as a copper(II) histamine unit may also serve for the chelation of the (deprotonated) 2-aminoacetate substructure of a-amino acids [51], Rizzarelli, Marchelli et al. used a respective j8-cyclodextrin derivative for the formation of the ternary complexes 36 and 37 with racemic... 

The review articles dealing with the application of cyclodextrin derivatives for a direct gas chromatographic separation of optically active components in the essential oils have been published by Bicchi et al. [15, 16]. 

C. Garcia-Ruiz, A.L. Crego and M.L. Marina, Comparison of charged cyclodextrin derivatives for the chiral separation of atropisomeric polychlorinated biphenyls by capillary electrophoresis. Electrophoresis, 24, 2657-2664, 2003. 

Sricharussin, W, Spajaree, C., Manee, Rung, T., and Sangsuri3ra, N. (2009). Modification of cotton febrics with j8-cyclodextrin derivative for aroma finishing,100,682-687. 

Zhong, Q. He, L. Beesley, T. E. Trahanovsky,W. S. Sun, R Wang, C. Armstrong, D.W. Development of dinitrophenylated cyclodextrin derivatives for enhanced enantiomeric separations by high-performance liquid chromatography. J. Chromatogr., A 2006,1115, 19—45. 

Takahisa, E. and K. H. Engel, 2005b. 2,3-Di-0-methoxymethyl-6-0-ferf-butyl-dimethylsilyl-Y-cyclodextrin A new class of cyclodextrin derivatives for gas chromatographic separation of enantiomers,... 

Thiele C, Auerbach D, Jung G et al (2011) Nanoparticles of anionic starch and cationic cyclodextrin derivatives for the targeted delivery of drugs. Polym Chem 2 209-215... 

Separation Technologies Inc., of Whippany, NJ, USA. In 1991, the same company received two global patents for the use of two specific cyclodextrin derivatives for the separation of enantiomers by capillary GC. This technology is known by the trade name of Chiraldex. Various Chiraldex columns have been developed, using the prefixes A, B and G for the a-, and y-CDs, respectively [92], Similarly, Supelco have also developed various chiral stationary phases under the trade name of Dex a-Dex, S-Dex and y-Dex CSPs on fused silica capillary columns containing premethylated a-, and y-CDs coupled to a phenyl that contains a stationary polysiloxane... 

Hynes JL, Shamsi SA, O Keeffe F, Darcy R, Warner IM (1998) Cationic P-cyclodextrin derivative for chiral separations. J Chromatogr A 803 261-271... 

Gas chromatography (GC) has also been used for preparative purposes, but is restricted to relatively volatile racemates such as anesthetics, pheromones or monoterpenes and, therefore, very few applications are reported. Nevertheless, in the cases to which GC may be applied, it could be considered as an economical alternative to HPLC. Most of the resolutions of enantiomers were performed on cyclodextrin-derived CSPs [109, 144-153], and only on very few occasions were other chiral selectors used [153]. 

A chiral GC column is able to separate enantiomers of epoxy pheromones in the Type II class, but the applications are very limited as follows a custom-made column packed with a p-cyclodextrin derivative as a liquid phase for the stereochemical identification of natural 3,4- and 6,7-epoxydienes [73, 74] and a commercialized column of an a-cyclodextrin type (Chiraldex A-PH) for the 3,4-epoxydiene [71] (See Table 3). The resolution abilities of chiral HPLC columns have been examined in detail, as shown in Table 7 and Fig. 14 [75,76, 179]. The Chiralpak AD column operated under a normal-phase condition separates well two enantiomers of 9,10-epoxydienes, 6,7-epoxymonoenes and 9,10-epoxymonoenes. Another normal-phase column, the Chiralpak AS column, is suitable for the resolution of the 3,4-epoxydienes. The Chiralcel OJ-R column operated under a reversed-phase condition sufficiently accomplishes enantiomeric separation of the 6,7-epoxydienes and 6,7-epoxymonoenes. 

Addition of an aqueous solution of PEG to a saturated aqueous solution of a-CD at room temperature did not lead to complex formation unless the average molecular weight of PEG exceeded 200 [46]. Moreover, carbohydrate polymers such as dextran and pullulan failed to precipitate complexes with PEG, and the same was true for amylose, glucose, methyl glucose, maltose, maltotriose, cyclodextrin derivatives, such as glucosyl-a-CD and maltosyl-a-CD, and water-soluble polymers of a-CD crosslinked by epichlorohydrin. These facts suggested to Harada et al. the direction for further research. 

Preparation of cyclodextrin derivatives substitution at a secondary hydroxyl group of the cyclodextrin annulus. Murakami and cowor-kers described a new and convenient method for the regioselective tosylation of the 2-hydroxyl groups of alpha, beta, and gamma cyclodextrin by means of a cyclic tin intermediate. The method is based on the reaction of dibutyltin oxide with 1,2-diols to form five-membered dibutyl-stannylidene derivatives. Useful yields of the 2-6>-tosyl derivatives of the cyclodextrins were obtained. 

Bicchi C, D Amato A, Rubiolo P, Cyclodextrin derivatives as chiral selectors for direct gas chromatographic separation of enantiomers in the essential oil, aroma and flavor J Chromatogr A 843 99-121, 1999. 

Perpentylated cyclodextrins are liquids even below room temperature. Cyclodextrin derivatives (Lipodex-stationary phases, Table 2) have been used in undiluted form for the separation of enantiomers of many classes of compounds on deactivated glass capillary columns169 176 (Figures 18 and 19). 

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