betadex and sodium-borate

An alternative method for simultaneous baseline separation of α and β-acids homologues and isomers in hop by CD-MEKC with UV detection was proposed. The optimized background electrolyte was composed of 30 mmol/L sodium tetraborate solution, 45 mmol/L sodium dodecyl sulfate, 20 mmol/L β-cyclodextrin and 10% v/v acetonitrile. The instrumental conditions were evaluated by using a 3

Topics: Acids; beta-Cyclodextrins; Borates; Chromatography, Micellar Electrokinetic Capillary; Electrophoresis, Capillary; Humulus; Isomerism; Sodium Dodecyl Sulfate; Spectrophotometry, Ultraviolet

In this work, a new chiral micellar electrokinetic chromatography with laser-induced fluorescence detection (chiral-MEKC-LIF) method is proposed to identify and quantify D- and L-amino acids in three lines of transgenic maize and their corresponding nontransgenic parental lines grown under identical conditions. The optimized procedure includes amino acids extraction, derivatization with FITC and chiral-MEKC-LIF separation in a background electrolyte composed of 100 mM sodium tetraborate, 80 mM SDS, and 20 mM beta-CD at pH 10.0. The D- and L-forms of Arg, Ser, Ala, Glu, and Asp, corresponding to the majority amino acids usually found in maize, are separated in less than 25 min with efficiencies up to 890,000 plates/m and high sensitivity (i.e., LODs as low as 160 nM were obtained for D-Arg for a signal-to-noise ratio of three), allowing the detection of 1% D-Arg in the presence of 99% of its opposite enantiomer. Using this method, different D-amino acids are detected in all investigated maize samples providing the reproducible quantification of the D-enantiomeric excess (% d-aa) for each amino acid calculated as % D-aa = 100D-aa/(D-aa + L-aa). Thus, significant differences were observed among the % d-aa values for the different conventional varieties (Aristis, Tietar, and PR33P66 maize) as could be expected from their natural variability. More interestingly, comparing each conventional maize with its corresponding transgenic line, very similar % D-aa values were obtained for one of the studied maize couples (Tietar vs Tietar-Bt) what could be presented as a new proof of their substantial equivalence. However, significant differences in the % d-aa values were observed for the other lines of maize studied. It is concluded that enantioselective procedures can open new perspectives in the study of transgenic organisms in order to corroborate (or not) the equivalence with their conventional counterparts.

Topics: Amino Acids; beta-Cyclodextrins; Borates; Chromatography, Micellar Electrokinetic Capillary; Electrolytes; Fluorescein-5-isothiocyanate; Fluorescence; Fluorescent Dyes; Hydrogen-Ion Concentration; Lasers; Plants, Genetically Modified; Sensitivity and Specificity; Sodium Dodecyl Sulfate; Stereoisomerism; Time Factors; Zea mays

Cyclodextrins (CDs) have been identified as a viable alternative to viral vectors for use in therapeutic applications. Here, the stability of the complex formed between the a multiply charged, cationic, fully substituted heptakis-(6-amino-2-galactosyl)cyclodextrin (BCDX12) with a multiply charged 12-mer hexachlorofluorescein tagged arabinopolynucleotide (Hex-PAH) have been evaluated.. The stability of complexes of Hex-PAH and BCD-X12 was studied with respect to mole ratio (1:1, 1:2, and 1:5 Hex-PAH:BCD-X12), pH, buffer concentration, temperature, and agitation using capillary electrophoresis with laser induced fluorescence detection (CE/LIF). Two neutral CDs and an additional cationic CD were also tested under the same analytical conditions to determine their ability to form complexes.. Hex-PAH:BCDX12 complexes at mole ratios of 1:2 were stable in 10 mM (160 mM total borate concentration) sodium tetraborate buffer at pH 7.5 and at temperatures of 4 degrees C and 25 degrees C over 48 hours. However, the Hex-PAH:BCD-X12 complex was less stable at 37 degrees C and at higher buffer concentrations and pH values. Strong vortex mixing prior to analysis was found to disrupt the complex. Of the four CDs tested for their ability to complex with Hex-PAH, only BCDX12 formed stable complexes with Hex-PAH under the test conditions.. Capillary electrophoresis was found to be well suited to test the stability of cyclodextrin-nucleotide complexes. CE/LIF indicated that only a single Hex- PAH:BCD-X12 complex was formed at all formulation ratios, and that the complexes were electrophoretically identical to each other, and increasing the molar ratio beyond 1:2 did not contribute measurably to complex stability. Storage temperature and agitation conditions were found to influence complex stability. Since no stable complexes were formed with neutral cyclodextrins, the results support the hypothesis of a 'charge associated' complex rather than an inclusion complex, although inclusion complexes cannot be excluded on the basis of these studies.

Topics: Arabinonucleotides; beta-Cyclodextrins; Borates; Electrophoresis, Capillary; Fluoresceins; Fluorescence; Hydrogen-Ion Concentration; Lasers; Oligonucleotides; Temperature