Of dansyl amino acids

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

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.)...

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. 

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

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. 

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. 

However, the CMPA concept for CLEC. introduced by Lindner and co-workers139 for the resolution of dansyl amino acids using a chiral triamine and Zn(II) as transient metal ions parallel to the work of Gil-Av146, allowed the further development and successful use of amino acids and their derivatives together with Cu(II) as CMPAs in reverse-phase systems for the direct resolution of, for example, a-amino acids146. 

Solvent 3. Ethyl acetate-methanol-acetic acid, 2 1 1 (v/v/v) Standard mixture of dansyl amino acids in acetone, 1 mg/mL each Phe, Leu, Gly, Ala, Val. 

Thin-layer chromatography of dansyl-amino acids on a polyamide plate. A After solvents 1 (1.5% formic acid) and 2 (toluene-acetic acid). B After solvents 1,2, and 3 (ethyl acetate-methanol-acetic acid). See text for further details. 

B 7 In the TLC analysis of dansyl amino acids, why does dansic acid move very slowly during development in solvents 2 and 3 ... 

Chiral mobile-phase modifiers 133 Separation of dansylated amino acids using /3-cyclodextrin in mobile phase and reversed-phase column... 

AR Martins, AP Afonso. A practical approach to improve the resolution of dansyl-amino acids by high-performance liquid chromatography. J Liq Chromatogr Relat Technol 19 467-476, 1996. 

Major advances have been made in recent years in the development and optimization of chiral resolutions of derivatized CD-based CSPs [68]. It has been reported that CSPs based on CD derivatives were more enantioselective than CSPs obtained from native CDs [68]. An acetyl /CCD column exhibited enhanced separation for scopolamine in comparison to the native / -CD CSP in the reversed-phase mode [69]. The enantiomeric resolution of some drugs was compared on the native [l-CD and on CSPs based on (S)- and (i )-2-hydroxy-propyl /I-CD, and the best resolution was reported on the derivatized CSPs [44]. Five types of natural and chemically modified [>- or y-C D stationary phases were developed and used for the chiral resolution of dansyl amino acids. The best resolution of dansyl amino acids was provided by y-CD CSPs [70]. 

TABLE 7 Effects of the Structures of /J-CD Phases1 on the Chiral Resolution of Dansyl Amino Acids... 

Bhushan and Parsad [65] resolved dansyl amino acids on erythromycin impregnated thin-layer chromatographic (TLC) silica plates. The mobile phase used was different ratios of 0.5 M aqueous NaCl-acetonitrile-methanol. Further, Bhushan and Thiong o [66] achieved the chiral resolution of dansyl amino acids on silica TLC plates impregnated with vancomycin chiral selector. The mobile phase used for this study was acetonitrile-0.5 M aqueous NaCl (10 4 and 14 3, v/v). The chiral recognition mechanisms of antibiotic CSPs in sub-SFC, SFC, CEC, and TLC modes of chromatography were found to be similar to HPLC. 

FIGURE 6 Chromatograms of the chiral resolution of dansyl amino acids on the Radialpak Ci8 column using water-acetonitrile (80 20, v/v) as the mobile phase containing the Cu(II) complex of 0SVSt)-2-hydroxypropyl-(5 )-phenylalaninamide as the CMPA. I DNS-Glu II DNS-a-Nbu III DNS-Ser. (From Ref. 56.)... 

The approach of CMPAs has also been used in thin-layer chromatography (TLC) for the chiral resolution of a variety of racemic compounds [100-110]. Lepri et al. [104,105] used BSA as a mobile phase additive for the chiral resolution of dansyl amino acids and other drugs by TLC. Armstrong et al. [101,102] used unde-rivatized and hydroxyethyl and hydroxypropyl /I-cyclodextrins for the chiral resolution of dansyl amino acids, alkaloids, and other compounds. Aboul-Enein... 

Chirality of derivatized cyclodextrin was used for recognition of stereoisomers. Phenylazobenzoyl modified y-cyclodextrin was anchored onto silica gel used as stationary phase in HPLC and photoresponsive chromatographic behavior of dansyl amino acid enantiomers was studied [64],... 

Yoshida, K. Nakagama, T. Uchiyama, K. and Hobo, T. (1998) Photo responsive chromatographic behavior of dansyl amino acid enantiomers using azobenzene-modified cyclodextrin stationary phases in... 

Although stack injection has been employed previously [316,582], the benefit of stacking for sample pre-concentration was only studied in detail later [346]. With the sample buffer (0.5 mM) at a 10-fold lower conductivity than the separation buffer (5 mM), simple EK stacking using the gated injection was observed. This was applied to the separation of dansylated amino acids (dansyl-lysine, didansyl-lysine, dansyl-isoleucine, and didansyl-isoleucine) [346]. 

An impressive application of the chelated metal technique was recently reported by LePage et al (26). Optical isomers of dansyl amino acids were resolved using an optically active metal chelate. High alpha values and high efficiency conditions were achieved, as shown in figure 5. 

Figure 8.2. Capillary zone electrophoretic separation of dansyl amino acids. (From ref. 11. Reprinted with permission from J. W. Jorgenson and K. D. Lukacs, Anal. Chem., 53, 1298 (1981). Copyright 1981 American Chemical Society.)...

Mechref Y, Smith JT, El Rassi Z. Micellar electrokinetic capillary chromatography with in situ charged micelles. VII. Expanding the utility of alkylglycoside-borate micelles to acidic and neutral pH for capillary electrophoresis of dansyl amino acids and herbicides. J Liq Chromatogr 1995 18 3769. 

Courderot, C.M. et al. Chiral discrimination of dansyl-amino-acid enantiomers on tei-coplanin phase sucrose-perchlorate anion dependence. Anal. Chim. Acta 2002, 457, 149-155. 

LePage, J.N. Lindner, W. Davies, G. Seity, D.E. Karger, B.L. Resolution of the optical isomers of dansyl amino acids by reversed phase liquid chromatography with optically active metal chelate additives. Anal. Chem. 1979, 51 (3), 433-435. 

The dansyl derivatization has been extensively studied to label a- or 8-amino groups. DNS derivatives are formed within 2 min and are detected by either UV or fluorescence. A typical example of a separation of dansyl amino acids is illustrated in Fig. 3. 

Fig. 3 RP-HPLC analysis of a mixture of dansyl amino acids. Conditions stationary phase 4 /xm Nova Pak Cig mobile phase gradient of methanol and tetrahydrofuran versus aqueous phosphate buffer detection in a fluorescent detector excitation 338 nm, emission 455 nm. Amino acids are abbreviated by the one-letter system. (From Ref. 12.)...

A8. Arnott, M. 8., and Ward, D. N., Separation of dansyl amino acids in a single analysis. Anal. Biochem. 21, 50-56 (1967). 

Dll. Deyl, F., and Rosmus, J., Thin-layer chromatography of dansyl amino acid derivatives. J. Chromatogr. 20, 514-520 (1965). 

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