Amines, dansylation

Derivatization is also useful to detect volatile metabolites. Liu et al. [282] described a specific, rapid, and sensitive in situ derivatization solid-phase microextraction (SPME) method for determination of volatile trichloroethylene (TCE) metabolites, trichloroacetic acid (TCA), dichloroacetic acid (DCA), and trichloroethanol (TCOH), in rat blood. The metabolites were derivatized to their ethyl esters with acidic ethanol, extracted by SPME and then analyzed by gas chromatography/negative chemical ionization mass spectrometry (GC-NCI-MS). After validation, the method was successfully applied to investigate the toxicokinetic behavior of TCE metabolites following an oral dose of TCE. Some of the common derivatization reagents include acetyl chloride and TV-methyl-iV- ft-b u (y Idi methyl si I y I) tro (1 uoroacctam i nc (MTBSTFA) for phenols and aliphatic alcohols and amines, dansyl chloride and diazomethane for phenols, dansyl chloride for amines, acidic ethanol and diazomethane for carboxylic acids, and hydrazine for aldehydes. 

Peptide analysis, sequencing and synthesis All fluorescent dye labels with reactive groups for amine, dansyl chloride, dabsyl chloride. Fluorescent isothiocyanates. N-Terminal amino acid analysis, peptide sequencing, peptide synthesis, labeling peptides in solution, solid-phase synthesis of labeled peptides 37... 

Tris(2,2 -bipyridyl)ruthenium(n) (Rulbyp) ) is used as the electrogenerated CL (ECL) reagent for the amino compounds in the LC-CL detection system. The CL reaction is supposed to proceed as follows initially, the oxidation of Rulbypls to Ru(byp) is performed at the electrode surface, and then Ru(byp) reacts with amines to emit light at 620 nm. The ECL intensity is proportional to the amount of amines, and the order of increasing CL intensities is tertiary > secondary > primary amines. Dansyl derivatization of primary, secondary, and tertiary amines are used to increase the sensitivity. DNS-Glu can be determined by ECL with the detection limit of 2 pmol. 

Appllca.tlons. Various A/-derivatives of amino acids (qv) are resolvable on BSA columns. These /V-amino acid derivatives include ben2enesulfonyl-, phthalimido-, S-dimethylarnino-l-naphthalenesulfonyl- (DANSYL-), 2,4-dinitrophenyl- (DNP-), and 2,3,6-trinitrophenyl- (TNP-) derivatives (30). Amines such as Prilocain, ( )-2-(prop5lamino)-(9-propiono-toluidide, a local anesthetic (Astra Pharm. Co.), are also resolved on BSA. The aromatic amino acids DL-tryptophan, 5-hydroxy-DL-tryptophan, DL-kynurenine [343-65-7] C qH 2N 2 3 3-hydroxy-DT.-kynurenine [484-78-6] and dmgs... 

An excellent discussion on derivatization techniques has been given by Lawrence (17) including a detailed discussion on pre-column derivatization (18) and post-column derivatization (19). Probably, the more popular procedures are those that produce fluorescing derivatives to improve detector sensitivity. One of the more commonly used reagents is dansyl chloride (20), 5-dimethylamino-naphthalene-1-sulphonyl chloride (sometimes called DNS-chloride or DNS-C1). The reagent reacts with phenols and primary and secondary amines under slightly basic conditions forming sulphonate esters or sulphonamides. 

Reports on the use of fluorescent derivatives abound (5). Some reagents have become widely used. The dansyl group is probably the most thoroughly studied. Dansyl chloride has been widely used as a fluorescent derivatizing reagent for HPLC (6,7). It reacts readily with primary and secondary amino groups (7) and with phenols (8), but forms derivatives of alcohols very slowly (9). The lower detection limit for dansyl derivatives of aliphatic amines is in the range of 300 femtomoles per injection. 

Dansyl chloride that exhibits a blue intrinsic fluorescence, reacts with many amines and phenols to yield derivatives with fluorescence of another color. 

Note Tertiary amines do not react with dansyl chloride and can be detected by spraying afterwards with Wagner s reagent [1]. The detection limits for amines are in the lower nanogram range. 

Dansylamides 104,106 — 108 Dansylamino acids 73,107,108 Dansylation 72 ff amines (prim, and sec.) 73 amino acids 73 -, phenols 73 prechromatographic 72 ff with dansyl semicadaveride 73, 53... 

It has been demonstrated that dendrimers can be used also as fluorescent sensors for metal ions. Poly(propylene amine) dendrimers functionalized with dansyl units at the periphery like 34 can coordinate metal ions by the aliphatic amine units contained in the interior of the dendrimer [80]. The advantage of a dendrimer for this kind of application is related to the fact that a single analyte can interact with a great number of fluorescent units, which results in signal amplification. For example, when a Co ion enters dendrimer 34, the fluorescence of all the 32 dansyl units is quenched with a 32-fold increase in sensitivity with respect to a normal dansyl sensor. This concept is illustrated in Fig. 3. 

Dansyl chloride Dns-Cl Primary and secondary amines, phenols, euaino acids and imidazoles 550, 617-619... 

Dansyl chloride is the most widely used of the derivatizing reagents. It forms derivatives with primary and secondary amines readily, less rapidly with phenols and imidazoles, and very slowly with alcohols. The reaction medium is usually an aqueous-organic sixture (e.g., 1 1 acetone-water) adjusted to a pH of 9.5-10. Dansyl chloride has two major application areas. It is used to determine small amounts of amines, amino acids and phenols, as... 

The amine-reactive 5-(dimethylamino)naphthalene-l-sulfonyl (dansyl) chloride 28 [80] and related fluorophores [81, 82], as well as the 5-((2 aminoethyl)amino) naphthalene-1-sulfonic acid (EDANS) 29, are included in the naphthalene fluorophore family. Derivatives of the latter, such as compound 30, exhibit a Lm.ix/ Lem 336/520 nm, molar absorptivity (e) of 6.1 x 103 M-1 cm-1, and a fluorescent quantum yield of 0.27 in water [83], The use of EDANS is particularly interesting in FRET experiments [84, 85]. Furthermore, 4-amino-3,6-disulfonylnaphthalimides (e.g., Lucifer yellow 31), associated to a longer absorption (Lmax 428 nm) [86] are suitable polar tracers [87]. 

Amines are another important group of analytes. Mellbin and Smith [72] compared three different fluorescent reagents, dansyl chloride, 4-chloro-7-nitrobenzo-1,2,5-oxadiazole, and o-phthaldialdehyde, for derivatization of alkylamines. The dansyl tag was found to be the most effective. Hamachi et al. [73] described the application of an HPLC-POCL method for determination of a fluorescent derivative of the synthetic peptide ebiratide. Another comparative study was done by Kwakman et al. [74], where naphthalene-2,3-dialdehyde and anthracene-2,3-dial-dehyde were evaluated as precolumn labeling agents for primary amines. The anthracene-2,3-dialdehyde derivatives were not stable, especially in the presence of hydrogen peroxide, and the POCL detection of these derivatives was therefore... 

Enhancements in the sensitivity with which amino acids containing a primary amine group can be determined have been achieved by derivatization. Chen and Sato [37] reported derivatization with divinyl-sulfone-reduced limits of detection by several orders of magnitude, while Lee and Nieman [38] reported derivatization with dansyl-chloride-reduced limits of detection by a factor of three. 

Vogtle F, Gestermann S, Kauffmann C et al (2000) Coordination of C02+ ions in the interior of polypropylene amine) dendrimers containing fluorescent dansyl units in the periphery. J Am Chem Soc 122 10389-10404... 

Dansyl Chloride (afluorotag) is invariably used to obtain fluorescent derivatives of proteins, amines and phenolic compounds, the excitation and emission wavelengths being 335 to 365 nm and 520 nm respectively. 

A good correlation between experimental retention times and calculated selectivities and molecular connectivities was found using the PRISMA model for seventeen dansylated biogenic amines present in foodstuffs and animal fodder251. 

Ab initio SCRF/MO methods have been applied to the hydrolysis and methanol-ysis of methanesulfonyl chloride (334). ° The aminolysis by aromatic amines of sulfonyl and acyl chlorides has been examined in terms of solvent parameters, the former being the more solvent-dependent process.Solvent effects on the reactions of dansyl chloride (335) with substituted pyridines in MeOH-MeCN were studied using two parameters of Taft s solvatochromatic correlation and four parameters of the Kirkwood-Onsager, Parker, Marcus and Hildebrand equations. MeCN solvent molecules accelerate charge separation of the reactants and stabilize the transition... 

The uniformity of these hyperbranched PAA grafts on PE films was studied by forming derivatives with visible and fluorescent dyes. These hyperbranched films were modified by treating an activated 3-PAA/PE film with an amine terminated p-methyl red dye (MR) 9 or with a dansyl amine 10 to form MR/3-PAA/PE or dansyl/3-PAA/PE films, respectively. Visual inspection under a light or fluorescence microscope showed that the methyl red-labeled and fluorescently labeled films were uniform in color and fluorescence. The methyl red/3-PAA/PE film derivafive showed a responsive color change wifh change in pH. The MR labeled 3-PAA/PE film was red after immersion in an acidic ethanol solution and yellow after treatment with a basic ethanol solution. 

Bushey, M.M., Jorgenson, J.W. (1989). Separation of dansylated methyl-d3-amine by micellar electrokinetic capillary chromatography with methanol modified mobile phase. Anal. Chem. 61 491—493. 

Further side-chain chemistry can be carried out either at one of the side chains attached to the five-membered ring [228-232] or at the pyrrolidine nitrogen [215, 224, 231, 233-239], For example, upon heahng 3-triphenylmethyloxazolidin-5-one (210) at reflux for 16 h with Cjq in equimolar amounts, 211 can be isolated in 39% yield [204], Subsequent treatment of 211 with trifluoromethanesulfonic acid, then with pyridine and dansyl chloride (DnsCl) yields the dansyl pyrrolidine derivative 213 in 76% yield (Scheme 4.35). The amine 212 is an intermediate in this reachon. 

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