carboxymethyl-beta-cyclodextrin and betadex

In this study, magnetic nanoparticles functionalized with carboxylated β-cyclodextrin (CM-β-CD; referred to Fe

Topics: Animals; beta-Cyclodextrins; Cholesterol; Egg Yolk; Ferrous Compounds; Magnetite Nanoparticles; Microscopy, Electron, Transmission; Milk; Spectroscopy, Fourier Transform Infrared; Thermogravimetry; X-Ray Diffraction

The enantioseparation of acidic and neutral compounds can be successfully achieved in capillary electrophoresis (CE) using dual cyclodextrin (CD) systems. This chapter describes how to separate the enantiomers of acidic or neutral substances using dual CD systems made up of a negatively charged CD derivative, i.e., sulfobutyl-β-CD (SB-β-CD) or carboxymethyl-β-CD (CM-β-CD), in combination with a neutral one, namely, heptakis(2,3,6-tri-O-methyl)-β-CD (TM-β-CD). An acidic compound (carprofen) and a weakly acidic drug (pentobarbital) were selected as model compounds.

Topics: beta-Cyclodextrins; Carbazoles; Electrophoresis, Capillary; Hydrogen-Ion Concentration; Models, Theoretical; Pentobarbital; Stereoisomerism

This paper investigated the effects of beta-cyclodextrins (beta-CD) and its two derivatives, hydroxypropyl-beta-cyclodextrin (HPCD) and carboxymethyl-beta-cyclodextrin (CMCD), on the solubility and biodegradation of 2-nitrophenyl by an Acinetbacter sp. Results showed that beta-CD, HPCD and CMCD could not be utilized by Acinetbacter sp. as sole carbon source and none of the CDs had toxic effects on the growth of the bacteria in the experiments; all the CDs could enhance the apparent solubility and accelerate the biodegradation of 2-nitrobipheny. It showed that biodegradation-accelerating effects of CDs on 2-nitrobiphenyl were correlated with their solubility-enhancing effects. Among three CDs investigated, CMCD had the most obvious effects both on the apparent solubility and the biodegradation, followed by beta-CD and HPCD.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Acinetobacter; beta-Cyclodextrins; Biodegradation, Environmental; Biphenyl Compounds; Nitrogen Compounds; Solubility; Spectrophotometry, Ultraviolet

A highly new charged cyclodextrin (CD) derivatives, (6-O-carboxymethyl-2,3-di-O-methyl)cyclomaltoheptaoses (CDM-beta-CDs), was synthesized and characterized as anionic reagents for capillary electrophoresis (CE) in an electrokinetic chromatography mode of separation. Substitution with dimethyl groups at the secondary hydroxyl sites of the CD is aimed at influencing the magnitude and selectivity of analyte-CD interactions, while substitution by carboxymethyl groups at the primary hydroxyl sites provides for high charge and electrophoretic mobility. Full regioselective methylation at the secondary hydroxyl sites was achieved in this work, while substitution at the primary hydroxyl sites generated a mixture of multiply charged products. The separation performance of CDM-beta-CD was evaluated using a variety of analyte mixtures. The results obtained from commercially available negatively charged cyclodextrins, heptakis(2,3-di-O-methyl-6-O-sulfo)cyclomaltoheptaose (HDMS-beta-CD) and O-(carboxymethyl)cyclomaltoheptaose (CM-beta-CD) with an average degree of substitution one (DS 1), were compared to CDM-beta-CD using a sample composed of eight positional isomers of dihydroxynaphthalene. Four hydroxylated polychlorobiphenyl derivatives, a group of chiral and isomeric catchecins, and chiral binaphthyl compounds were also separated with CDM-beta-CD. The effect of adding neutral beta-cyclodextrin (beta-CD) into the running buffer containing charged cyclodextrins was investigated and provided evidence of significant inter-CD interactions. Under certain running buffer conditions, the charged cyclodextrins also appear to adsorb to the capillary walls to various degrees.

Topics: Anions; beta-Cyclodextrins; Chromatography; Cyclodextrins; Electrophoresis, Capillary; Isomerism; Models, Molecular; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Quenched phosphorescence detection of camphorquinone in cyclodextrin-based electrokinetic chromatography provides very favorable detection limits, i.e., 7 x 10(-)(7) M, 3 orders of magnitude lower than conventional UV absorption detection at 200 nm. The detection is based on the dynamic quenching by the analyte of the strong phosphorescence emission of brominated naphthalenesulfonate, under deoxygenated buffer solution conditions. This approach has been used to detect (1S)-(+)- and (1R)-(-)-camphorquinone after enantiomeric separation by CE. Although the use of the negatively charged carboxymethyl beta-cyclodextrin (CM-beta-CD) alone was not successful, the addition of a second, neutral cyclodextrin, alpha-CD, provided an adequate enantiomeric separation of camphorquinone. Using 25 mM borate buffer (pH 8.5) with 10 mM CM-beta-CD and 20 mM alpha-CD (applied voltage 20 kV, ambient temperature), the enantiomeric separation was performed in approximately 14 min. The chiral method was applied to monitor the stereoselectivity of the biotransformation of a racemic mixture of camphorquinone by yeast. It was found that the enantiomeric ratio calculated from the peak areas in the electropherogram (RSD = 5%) after 24 h of incubation decreased from 0.92 for the control solution (culture medium without yeast) to 0.24 for the culture medium; a similar ratio of 0.25 was observed for cell extract solutions. Therefore, racemic camphorquinone is enantioselectively degraded by yeast, the biodegradation of (1S)-(+)-camphorquinone being faster than that of the (1R)-(-)-enantiomer.

Topics: alpha-Cyclodextrins; beta-Cyclodextrins; Bromine; Cyclodextrins; Electrophoresis, Capillary; Luminescent Measurements; Molecular Structure; Naphthalenesulfonates; Spectrophotometry, Ultraviolet; Stereoisomerism; Terpenes; Yeasts