TY - JOUR
T1 - Evaluation of newly synthesized and commercially available charged cyclomaltooligosaccharides (cyclodextrins) for capillary electrokinetic chromatography
AU - Culha, Mustafa
AU - Schell, Fred M.
AU - Fox, Shannon
AU - Green, Thomas
AU - Betts, Thomas
AU - Sepaniak, Michael J.
N1 - Funding Information:
This work was sponsored by the Division of Chemical Sciences, Office of Basic Energy Sciences, U.S. Department of Energy under Grant DE-FG02-02ER15331 with the University of Tennessee, Knoxville. The authors acknowledge Greg Hurst of Oak Ridge National Laboratory for his assistance with the MALDI-TOF MS experiments and David Baker of the University of Tennessee for helpful discussions regarding the syntheses.
PY - 2004/1/22
Y1 - 2004/1/22
N2 - A highly new charged cyclodextrin (CD) derivatives, (6-O-carboxymethyl-2,3- di-O-methyl)cyclomaltoheptaoses (CDM-β-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-β-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-β-CD) and O-(carboxymethyl)cyclomaltoheptaose (CM-β-CD) with an average degree of substitution one (DS 1), were compared to CDM-β-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-β-CD. The effect of adding neutral β-cyclodextrin (β-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.
AB - A highly new charged cyclodextrin (CD) derivatives, (6-O-carboxymethyl-2,3- di-O-methyl)cyclomaltoheptaoses (CDM-β-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-β-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-β-CD) and O-(carboxymethyl)cyclomaltoheptaose (CM-β-CD) with an average degree of substitution one (DS 1), were compared to CDM-β-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-β-CD. The effect of adding neutral β-cyclodextrin (β-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.
KW - Capillary electrophoresis
KW - Characterization
KW - Chiral separations
KW - Heptakis(6-O-carboxymethyl-2,3-di-O-methyl)cyclomaltoheptaose
KW - Neutral positional isomers
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U2 - 10.1016/j.carres.2003.10.004
DO - 10.1016/j.carres.2003.10.004
M3 - Article
C2 - 14698882
AN - SCOPUS:0346786356
SN - 0008-6215
VL - 339
SP - 241
EP - 249
JO - Carbohydrate Research
JF - Carbohydrate Research
IS - 2
ER -