Dansyl amino acids

Tnethanolaimne dansyl amino acids, enhancement dansyl amides... 

Sodiiun dodecylsulfate, cetyltrimethylam-monium chloride, sodium cholate, -cyclodextrin dansylated amino acids and polycyclic aromatic hydrocarbons > 45-fold 1% in water the greatest enhancement of fluorescence is that of sodium cholate on pyrene [263]... 

These workers used binary solvent systems over a range of mole fractions to determine, for each solute, the constants a and b of equation (8.2). For methyl and phenacyl esters, TLC was used, while overpressured layer chromatography (OPLC) was used for dansyl amino acids. Nurok and co-workers (11) also evaluated how the quality of a simulated separation varies with changing solvent strength by using the inverse distance function (IDF) or planar response function (PRF), as follows ... 

Righetti and co-workers [11] were one of the first to demonstrate the utility of classical isoelectric focusing for the chiral separation of small molecules in a slab gel configuration. In their system, dansylated amino acids were resolved enan-tiomerically through complexation with (i-cyclodextrin. Preferential complexation between the cyclodextrin and the derivatized amino acid induced as much as a 0.1 pH unit difference in the pK s of the dansyl group. 

Woods, R. and Wang, Kung-Tsung "Separation of Dansyl Amino Acids by Polyamide Layer Chromatography". Blochlm. Blophys. Acta., (1967), 133, 369. 

Mixing the additive in the eluent used as a mobile phase can also modify the chromatographic system (dynamic modification), but the use of modified adsorbents has led to an improvement of resolution. Example works include that by Armstrong and Zhou [11], who used a macrocyclic antibiotic as the chiral selector for enantiomeric separations of acids, racemic drugs, and dansyl amino acid on biphenyl-bonded silica. 

Figure 14 Chiral separation of dansyl amino acids by chiral polyacrylamide gel electrophoresis. Peak identification 1 = dansyl-L-glutamic acid, 2 = dansyl-D-glutamic acid, 3 = dansyl-L-serine, 4 = dansyl-D-serine, 5 = dansyl-L-leucine, 6 = dansyl-D-leu-cine. (From Guttman, A., Paulus, A., Cohen, A. S., Grinberg, N. and Karger, B. L., /. Chromatogr., 448, 41, 1988. With permission.)...

The Af-dansylated amino acid (e.g., glycine, leucine, proline) exhibits a yellow fluorescence. The sensitivity of detection for amino acids by this method is about 10 9 mol of amino acid. The advantage of this prodecure in comparison with that using dansyl chloride is the fact that it can be carried out in homogenous aqueous solution without addition of a cosolvent. 191... 

Capillary zone electrophoresis, an up-to-date high resolution separation method useful for proteins and peptides, has been shown to be a useful method for determining electrophoretic mobilities and diffusion coefficients of proteins [3], Diffusion coefficients can be measured from peak widths of analyte bands. The validity of the method was demonstrated by measuring the diffusion coefficients for dansylated amino acids and myoglobin. 

Dansylated amino acids Synthetic 0.1 jtmol L"1 (glutamine)... 

Dansyl chloride (dimethylaminonaphthalene-5-sulphonyl chloride) will react with free amino groups in alkaline solution (pH 9.5-10.5) to form strongly fluorescent derivatives (Figure 10.14). This method can also be used in combination with chromatographic procedures for amino acid identification in a similar manner to the FDNB reagent but shows an approximately 100-fold increase in sensitivity. This makes it applicable to less than 1 nmol of material and more amenable for use with very small amounts of amino acids liberated after hydrolysis of peptides. The dansyl amino acids are also very resistant to hydrolysis and they can be located easily after chromatographic separation by viewing under an ultraviolet lamp see Procedure 10.1. 

The formation of DNP or dansyl amino acid derivatives followed by chromatography or electrophoresis is a useful technique in certain circumstances. The preparation of DNP derivatives may be indicated when the sample for analysis contains a variety of other substances, removal of which would be complicated, leading possibly to considerable analytical errors. However, the derivative formation and extraction is time consuming and itself can introduce inaccuracies into the analysis and should be used only when it offers an advantage over the separation of untreated amino acids. 

Sharp, V.S. et al.. Enantiomeric separation of dansyl amino acids using macrocyclic antibiotics as chiral mobile phase additives by narrow-bore high-performance liquid chromatography. Chirality, 16, 153, 2004. 

Peyrin, E. et al., Dansyl amino acid enantiomer separation on a teicoplanin chiral stationary phase effect of eluent pH, J. Chromatogr. A, 923, 37, 2001. 

Peyrin, E. et ah. Interactions between d,L dansyl amino acids and immobilized teicoplanin study of the dual effect of sodium citrate on chiral recognition, Chromatographia, 53, 645, 2001. 

CE has been applied extensively for the separation of chiral compounds in chemical and pharmaceutical analysis.First chiral separations were reported by Gozel et al. who separated the enantiomers of some dansylated amino acids by using diastereomeric complex formation with Cu " -aspartame. Later, Tran et al. demonstrated that such a separation was also possible by derivatization of amino acids with L-Marfey s reagent. Nishi et al. were able to separate some chiral pharmaceutical compounds by using bile salts as chiral selectors and as micellar surfactants. However, it was not until Fanali first showed the utilization of cyclodextrins as chiral selectors that a boom in the number of applications was noted. Cyclodextrins are added to the buffer electrolyte and a chiral recognition may... 

Enantioseparation of dansyl amino acids, free amino acids, hydroxy acids, and dipeptides... 

Chen, Z., Ozawa, H., Uchiyama, K., and Hobo, T. (2003). Cyclodextrin-modified monolithic columns for resolving dansyl amino acid enantiomers and positional isomers by capillary electrochromatography. Electrophoresis 24, 2550-2558. 

Valko, I. E., Siren, H., and Riekkola, M. L. (1997). Determination of association constants of dansyl-amino acids and beta-cyclodextrin in N-methylformamide by capillary electrophoresis. Electrophoresis 18, 919-923. 

Fig. S6. Separation of D,L-dansyl amino acids. Conditions 0.65 oiAf L 2>isopropyl-dien-Zn(II) 0.17 A NH,Ac to pH 9.0 with aqueous NI 35/65 CH,CN/H,0 T - 30 flowrate 2 tnl/min column 15 cm by 4.6 mm i.d. S iun Hypersil C solutes CySO H -cysteic acid Ser - serine Trp - tryptophan thr - threonine Norval - norvaline Leu w leucine Norleu - norleucine Phe phenylalanine. Detection at 254 nm. Reprinted with permission from LePage ef at. C246), Am/. Chem. Copyright 1979 by the American Chemical Society.

Dansyl amino acids Cu-Dien-Zodl) ACN-HtO (40 60) Octadecyl 250... 

Dansyl-amino acids HP-/3 (DS 6.3) Nonlinear regression 59 pH dependence, pKa shift during complexation... 

Dansyl-amino acids P Double reciprocal 60 nonaqueous CE (A-methylformamide), 17-correction... 

Dansyl-amino acids P Nonlinear regression 61 estimation of Stokes radii and diffusion coefficents... 

G Galavema, R Corradini, A Dossena, R Marchelli, G Vecchio. Histamine-modified f -cyclodextrins for the enantiomeric separation of dansyl-amino acids in capillary electrophoresis. Electrophoresis 18 905—911, 1997. 

SG Penn, G Liu, ET Bergstrom, DM Goodall, JS Loran. Systematic approach to treatment of enantiomeric separations in capillary electrophoresis and liquid chromatography. I. Initial evaluation using propranolol and dansylated amino acids. J Chromatogr A 680 147-155, 1994. 

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