Dimethylaminonaphthalene chloride

For the sulfonation step, amino acids were added as their sodium salts. The reactions were carried out in cold aqueous solution, in which the sulfonamides were immediately precipitated. By the same method dansylations of amino acids could be accomplished with N-( 1 -dimethylaminonaphthalene-5-sulfonyl)-Af -methylimidazolium chloride ... 

Boyle, R. (1966) The reaction of dimethyl sulfoxide and 5-dimethylaminonaphthalene-l-sulfonyl chloride./. Org. Chem. 31, 3880-3882. 

Estradiol 5-Dimethylaminonaphthalene-l -sulfonyl chloride Lissamine rhodamine B sulfonyl chloride 87... 

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. 

One of the most widely used reagents for introduction of a fluorophor into primary and secondary amines is 5-dimethylaminonaphthalene-l-sulfonyl chloride, com-... 

Phenols I-Dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride)... 

Dansylation is often used for the determination of free and N-terminal amino acids. Dansyl chloride (5-dimethylaminonaphthalene-l-sulfonyl chloride, DNS-C1) reacts with the amino substituent of amino acids to form highly fluorescent derivatives [75,76]. The method is particularly useful for the analysis of trace components due to the high sensitivity of the products. The derivatives are usually separated by TLC on various types of layers. Separations of DNS-amino acids by flat-bed techniques have been reviewed [77]. Separations by column chromatography have been examined on polyamide [78] and Amberlite IRC-SO [79]. Although many variations of the dansylation reaction with amino acids have been reported, the one described below [77] appears to be the most common. 

A solution of 1-dimethylaminonaphthalene (CAUTION possible carcinogen) (0.17 g, 1 mmol) in dry ether (2 ml) is stirred at room temperature as butyllithium ( 1.7 M in hexane, 4.5 mmol) is added. The mixture is stirred for 48 h and then cooled to 0° and kept at that temperature as butylmagnesium chloride (2 m in ether, 6.8 mmol) is added. After 20 min the mixture is cooled to -5° and maintained at this temperature for 4 h while dry oxygen is passed into the stirred solution. The mixture is poured into a stirred mixture of water (100 ml), acetic acid (10 ml) and zinc powder (1 g), and stirring is continued until effervescence ceases. The mixture is filtered, and the ethereal layer is separated, washed with saturated aqueous sodium hydrogencarbonate... 

SYNS 1 -CHLOROSULFONYL-5-DIMETHYL-AMINONAPHTHALENE DANSYL DANSYL CHLORIDE DIMETHYLAMINONAPHTHALENE-SULFONYL CHLORIDE 1-DIMETHYLAAIINO-NAPHTHALENE-5-SULFONYL CHLORIDE 1-piMETHYXAMINO)-5-NAPHTHALENESULFONYL-CHLORIDE 5-DIMETHYLAMINONAPHTHYL-5-SL LFONYL CHLORIDE... 

Dansyl chloride (5,N,N-dimethylaminonaphthalene-1-sulfonyl chloride) Fluorescent (ex. 360-385 nm, em. 460-495 nm) UV 254 nm Low pmol 60-90 min precolumn Multiple products, critical concentration, difficult separation leads to long separation time Stable product... 

Fluorescent dye-polypeptide conjugates were prepared by labeling with either fluorescein isothiocyanate adsorbed onto Celite (51) or with 1-dimethylaminonaphthalene sulfonyl chloride (DNS) dissolved in ethanol (65). The degree of labeling was determined from the amount of dye on the polypeptide estimated by fluorescent intensity or ultraviolet absorption measurements and from the concentration of the polypeptide determined by Kjeldahl nitrogen. There were generally two to four dye residues per polypeptide molecule. 

Rosier and Van Peteghem (1988) described a rapid method for the extraction, derivatization, and determination by HPLC of the 5-dimethylaminonaphthalene-l-sulphonyl (dansyl chloride) derivatives of putrescine, cadaverine, histamine, spermidine, and spermine from fish. Comparison of this procedure to earlier methods reflected considerable reduction in the time needed for sample preparation (from approx 8 to 0.5 hr) and cost (use of water and methanol instead of acetonitrile). 

Dansyl chloride (DNS-Cl) (l-dimethylaminonaphthalene-5-sulphonyl-chloride). This reagent was originally introduced into protein chemistry for end-group analysis over twenty years ago (Gray and Hartley, 1963) and has been widely used because of the simplicity of the reaction and its ability to react with both primary and secondary amines, unlike OPA and fluram. Furthermore, in contrast to other fluorescent reagents, the dansyl derivatives are stable to acid hydrolysis, and can therefore be used in N-group labelling before hydrolysis. HPLC separations of dansyl derivatives have recently been published (Tapuhi et al., 1981). Sensitivity of detection is at the low picomole level. The sensitivity is limited because of the side-reactions which can occur with lysine and, to a lesser extent, histidine and tyrosine. 

Similarly, phosphohpids containing primary amino groups can be derivatized with DNS-Cl (l-dimethylaminonaphthalene-5-sulphonyl chloride). DNS derivatives are highly fluorescent and, using an excitation wavelength of 342 nm and emission wavelength of 500 nm, a lower limit of detection of about 20 pmol has been achieved (Chen et al., 1981). 

A very sensitive fluorimetric nethod (16) based on the reaction of clonidine hydrochloride with l-dimethylaminonaphthalene-5-sulphonyl chloride (dan-syl chloride) to give a highly fluorescent derivative. 

Another methodology described in this volume is the use of l-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride) in the estimation of ammo acid levels. A double-isotope dansyl microassay for cerebral amino acids is described in detail, including the use of thin-layer chromatographic techniques for the separation of the dansyl derivatives The usefulness of the double-isotope labeling in overcoming problems inherent m the dansyl procedure is discussed by the author. Apart from a liquid scintillation counter, which is available in most laboratories, no sophisticated or expensive equipment is required for the microassay On the other hand, extensive and time-consuming manual manipulations are required for the procedure. 

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