Cyclodextrins carboxymethyl

Cyclodextrins carboxymethylated at the secondary rim have been evaluated as chemzymes for glycoside hydrolysis. ... 

Terabe, S., Ozaki, H., Otsuka, K., and Ando, T., Electrokinetic chromatography with 2-O-carboxymethyl-P-cyclodextrin as a moving "stationary" phase, /. Ckromatogr., 332, 211, 1985. 

CM-fi-CD Carboxymethyl-beta-cyclodextrin CSP Chiral stationary phase(s)... 

Prbpy, 5-(2-MePr)bpy and 5-(2,2-Mc2Pr)bpy have been prepared and characterized. The mer-and /uc-isomers of each complex have been isolated by use of cation-exchange column chromatography as the steric requirements of the R group increase, the percentage of the /uc-isomer decreases. Enantiomers of [Ru(5-Prbpy)3] + were separated on SP Sephadex C-25. Electro-kinetic chromatography has been used to separate the enantiomers of [Ru(104)3] " anionic carboxymethyl-/ -cyclodextrin was employed as the chiral mobile phase additive. ... 

S Sabbah, GKE Scriba. Separation of dipeptide and tripeptide enantiomers in capillary electrophoresis using carboxymethyl-beta-cyclodextrin and succinyl-beta-cyclodextrin. Influence of the amino acid sequence, nature of the cyclodextrin and pH. Electrophoresis 22 1385-1393, 2001. 

S Sabah, GKE Scriba. pH-Dependent reversal of the chiral recognition of tripeptide enantiomers by carboxymethyl-/3-cyclodextrin. J Chromatogr A 833 261-266, 1999. 

Therefore, the authors have synthesized heptakis(carboxymethyl)-substituted a-cyclodextrin which was combined with hydrophobic ammonium to afford 9 (Figure 13), whereby the number of carboxylate-ammonium ion pairs was regulated to six. This compound was incorporated into BUM and subjected to singlechannel current measurements. The current-voltage plot gave a single straight line to afford a conductance level of 7.7 pS under several different experimental conditions. Then the modified cyclodextrin successfully controlled the ion channel structure and therefore the conductance. 

Many CDs have been successfully used to solubilize insoluble drugs, here are a partial list of CD derivatives reported in the literature fflFCD, SBE-ft-CDs, randomly methylated-P-cyclodextrin (RM-p-CD), 2,3,6-partially methylat flcyclodextrin (PM-ft-CD), glucosyl-ft-CD (G1-P-CD), maltosyl-p-cyclodextrin (G2- -CD), hydroxyethyl-p-cyclodextrin (He-p-CD), diethyl-P-cyclodextrin (DE-p-CD)P-carboxymethyl-Qethyl- -cyclodextrin (CME-p-CD), and (2,6-oG>-methyl)-p-cyclodextrin (DOM-p-CD). 

On-chip chiral separation of enantiomers of adrenaline, noradrenaline, and dopamine was achieved using a mixture of carboxymethyl-p-cyclodextrin (CMCD) and a polyamidoamine dendrimer (Starburst) [120], On-chip chiral separation of enantiomers of homovanillic acid, DOPA, cDOPA, methoxy-tyramine (MT), metanephrine, and normetanephrine was achieved using a mixture of 18-crown-6-ether and carboxymethyl-P-cyclodextrin [120],... 

Zhao, H. and Vance, G. F. (1997). Intercalation of carboxymethyl-p-cyclodextrin into magnesium-aluminium layered double hydroxides. J. Chem. Soc., Dalton Trans., 1961. 

In electrokinetic chromatography (EKC, electroosmosis, electrophoresis) the highly soluble ionic cyclodextrin-derivatives (e.g. carboxymethyl-6-cyclodextrin) are employed (47). A non-charged guest will migrate in the electric field, because it is transported by the charged cyclodextrin host. 

Chankvetadze et al. have demonstrated the potential of flow-counterbalanced capillary electrophoresis (FCCE) in chiral and achiral micropreparative separations [27], Unlimited increase of separation selectivity can be achieved for binary mixtures, such as (+ )-chlorpheniramine with carboxymethyl-(3-cyclodextrin chiral selector, or a- and (3-isomers of a asparatame dipeptide. The carrier of the chiral selector or pseudo-stationary phase, electroosmotic flow (EOF), pressure-driven flow, or hydrodynamic flow can be used as a counterbalancing flow to the electrophoretic mobility of the analyte or vice versa, resulting in dramatic changes of the effective mobilities of the sample mixture components [28], This approach can be used for micropreparative CE, stepwise separations, and fraction collection of multicomponent mixtures [27],... 

A major problem associated with derivatized cyclodextrins is their chemical inhomogeneity due to various degrees of substitution, as has been demonstrated by Linnemayr et al. [457], e.g. for various commercial samples of methylated, (2-hy-droxyjpropylated and carboxymethylated P-cyclodextrins. This has led to the development of single-isomer derivatized CDs by Vigh and co-workers [458-461], e.g. of hepta-6-sulphato-P-CD [459], heptakis(2,3-diacetyl-6-sulphato)-p-CD [458], and hep-takis(2,3-dimethyl-6-sulphato)-p-CD [460, which are now commercialized by Regis Technologies. 

Cserhati, T. Forgacs, E. Charge-transfer chromatographic study of the complex formation of some steroidal drugs with carboxymethyl y-cyclodextrin. Anal. Biochem. 1997, 246 (2), 205-210. 

Adachi, H. Irie, T. Uekama, K. Manako, T. Yano, T. Saita, M. Combination effects of O-carboxymethyl-O-ethyl-P-cyclodextrin and penetration enhancer HPE-101 on transdermal delivery of prostaglandin Ej in hairless mice. Eur. J. Pharm. Sci. 1993, 1, 117-123. 

Park, S.Y. Park, J.K. Park, J.H. McNeff, C.V. Carr, P.W. Separation of racemic 2,4-dinitrophenyl amino acids on carboxymethyl-beta-cyclodextrin coated zirconia in RPLC. Microchem. J. 2001, 70, 179-185. 

The feasibility of separating the enantiomers of chlopheniramine on a micropreparative scale was also recently shown by applying flow-counterbalanced CE using carboxymethyl (l-cyclodextrin as a chiral selector [200]. All these apphcations were performed at a mg scale or even less and cannot currently compete with the liquid chromatographic methods discussed previously. However, the scope and limitations of the electrophoretic approach still need to be challenged [201]. 

Uekama, K., Horikawa, T., Horiuchi, Y, Hirayama, F. In vitro and in vivo evaluation of delayed-release behaviour of diltiazem from its O-carboxymethyl-O-ediyl-p-cyclodextrin complex. J. Control Release 1993, 25, 99-106. 

Adachi, H., Irie, T., Hirayama, R, Uekama, K. Stabilization of prostaglandin Ej in fatty alcohol propylene glycol ointment by acidic cyclodextrin derivative, O-carboxymethyl- 0-ethyl-(3-cyclodextrin. Chem. Pharm. Bull. 1992, 40, 1586-1591. 

Uekama, K., Adachi, H., Irie, T. et al. Improved transdermal delivery of prostaglandin Ei through hairless mouse skin combined use of carboxymethyl-ethyl-(3-cyclodextrin and penetration enhancers. J. Pharm. Pharmacol. 1992, 44, 119-121. 

Fig. 5 A typical application of capillary electrophoresis for chiral separations of small peptides. Chiral separation of the isomeric dipeptides (A) of Asp-PheOMe and P-Asp-PheOMe and (B) of Asp-PheNH2 and P-Asp-PheNH2. The separation was carried out at pH 3.3 using 15 mg/mL of carboxymethyl-P-cyclodextrin as the chiral selector. (For details of experimental conditions, see Ref. 171.)...

M Fillet, I Bechet, Ph Hubert, J Crommen. Resolution improvement by use of carboxymethyl-P-cyclodextrin as chiral additive for the enantiomeric separation of basic drugs by capillary electrophoresis. J Pharm Biomed Anal 14 1107-1114, 1996. 

Furusaki, E., Ueno, Y., Sakairi, N., Nishi, N., and Tokura, S. 1996. Facile preparation and inclusion ability of chitosan derivative bearing carboxymethyl-beta-cyclodextrin. Carbohydr. Polym. 9, 29-34. 

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