A Reversible Gel for Chiral Separations

Dowling, Victoria A.; Charles, Joseph A. M.; Nwakpuda, Emily; McGown, Linda B.

doi:10.1021/ac0400010

Cited by 22 publications

(15 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We must consider the structures of the chiral compounds as well. Figure 4 shows the structures of the chiral compounds used in this work as well as those examined in the previous work [17,24]. First, comparison of the structures of those compounds used in the migration time studies (Table 4) shows that compounds with two fused rings and extensive p electron systems exhibit greater interactions with the G-gels than those with single ring structures.…”

Section: Studies Of Other Chiral Compoundsmentioning

confidence: 91%

“…It has been demonstrated that gels formed by selfassembly of guanosine compounds (G-gels) exhibit chiral selectivity [16,17]. The building block of G-gels is a G-tetrad formed through Hoogsteen hydrogen bonding between each of four guanines and its two nearest neighbors [18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

“…Previous work showed that a G-gel formed by guanosine-5 0 -monophosphate (GMP), which is anionic at the separation pH of 7, could resolve the D and L forms of the drug propranolol, which is cationic at pH 7, in capillary gel electrokinetic chromatography [17]. Subsequently, it was observed that the G-gels are effective for some chiral compounds but not for others [24].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Chiral selectivity of guanosine media in capillary electrophoresis

Dong

McGown

2011

Electrophoresis

Self Cite

View full text Add to dashboard Cite

Gels formed by self-association of monomeric guanosine compounds join numerous other agents such as cyclodextrins, crown ethers, chiral surfactants, antibiotics, proteins, and polysaccharides for chiral separations. Guanosine gels (G-gels) are self-assembled networks of hydrogen-bonded tetrads formed by guanosine nucleotides and their derivatives. The tetrads stack upon themselves to form columnar, helical aggregates that are stabilized by π-π interactions and centrally located cations. Previous work showed the effectiveness of G-gels formed by guanosine-5'-monophophate for separation of the enantiomers of the cationic drug propranolol using capillary electrophoresis. Subsequently, it was found that not all chiral compounds could be resolved into their enantiomers, leading us to investigate in this work the structural features that appear to be correlated to enantiomerically selective interactions of chiral compounds with G-gels. For those compounds (anionic 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate and zwitterionic tryptophan) for which enantiomeric resolution was achieved, the effects of experimental conditions and G-gel composition were examined. For other compounds with no net charge (hydrobenzoin and zwitterionic amino acids and derivatives), the migration times were used as an indicator of the extent of interaction with the G-gel run buffer. It was found that the extent of interaction alone does not determine the chiral selectivity of the G-gel, indicating that the mechanism of chiral separation involves particular structural characteristics of the chiral compounds.

show abstract

Section: Studies Of Other Chiral Compoundsmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Chiral selectivity of guanosine media in capillary electrophoresis

Dong

McGown

2011

Electrophoresis

Self Cite

View full text Add to dashboard Cite

show abstract

“…The properties of G-gels can be modulated as a function of temperature, monomer concentration, cations, and pH [18]. G-gels have previously been investigated for the separation of chiral compounds using extraction [19,20] and CGEKC [21].…”

Section: Introductionmentioning

confidence: 99%

Guanosine gel for sequence‐dependent separation of polymorphic ssDNA

et al. 2007

Self Cite

View full text Add to dashboard Cite

The separation of fluorescent-labeled ssDNA fragments of equal length based on differences in sequence was achieved through the use of guanosine gels (G-gels) formed by guanosine-5'-monophosphate (GMP) in capillary gel electrokinetic chromatography (CGEKC) with LIF detection. Baseline resolution was achieved for homodimers and homopentamers of A, T, and C. G-gel CGEKC provided better resolution than CZE, MEKC, or a sieving gel in CGE. Resolution improved with increasing GMP, indicating that the interaction is linked to structural organization of the G-gel. Fluorescence intensity and anisotropy show that the order of interaction with G-gels is T>C>A. We then investigated four conformationally similar, polymorphic 76-mers with A/G substitutions that are utilized in forensic DNA typing. Resolution was achieved by CGEKC but not CZE or CGE. In CGEKC, the negatively charged G-gels and oligonucleotides electromigrate toward the positive inlet while being driven by EOF to the negative outlet. The net forward velocity is the greatest for oligonucleotides most closely associated with the slower, more cumbersome G-gel network. For the 76-mers, resolution increases with increasing difference in guanosine content between strands and, for a given difference, with increasing total guanosines in the strands.

show abstract

“…Ephedrine enantiomers were separated and analyzed using the amino acid L-leucine as chiral discriminator [131]. Dowling et al [132] applied a guanosine gel as a chiral selector in CE for the enantioseparation of propranolol. Guanosine gels are reversible organized media that are formed through the self-association of guanosine compounds.…”

Section: Other Chiral Selectorsmentioning

confidence: 99%