L-Dimethylaminonaphthalene-5-sulfonyl

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. 

Scheme 12.70. A cartoon representation of the reaction between the Ala-Phe terminus amino acid from Schemes 12.68 and 12.69 with l-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride). After the initial sulfonamide forms, acid hydrolysis is used to destroy the entire peptide. The easily detected (fluorescent) dimethylsulfonamide can be readily...

During the course of protein chemistry research looking for fluorescent compounds sensitive to the surrounding hydrophobicity, Weber designed l-dimethylaminonaphthalene-5-sulfonyl chloride (DNS-Cl) in 1952 [23]. DNS-Cl reacts with primary and secondary amino compounds (Figure 6.2) to form a fluorescent derivative with a yellow-green fluorescence [24]. DNS—amino acids can be separated by both normal-phase and reversed-phase liquid chromatography [25] and... 

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

Oxosteroids, oxo bile acids 5-Dimethylaminonaphthalene-l -sulfonyl hydrazine 82, 83... 

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

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

The effect of pH on the fluorescence of some DNS- (5-dimethylaminonaphthalene-l-sulfonyl-) derivatives has been examined [32]. Fig. 2.7 shows the change in fluorescence intensity of DNS-4-methylthio-3,5-xylenol with variation in the pH of the solution. This may be explained in terms of Fig. 2.8 which shows possible resonance structures of DNS-derivatives. When protonated, as in D, the naphthoquinone-type resonance is prohibited, resulting in a loss of fluorescence. 

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. 

Seiler, N., Knodgen, B. Determination of di-and polyamines by high-performance liquid chromatographic separation of their 5-dimethylaminonaphthalene-l-sulfonyl derivatives. J Chromatogr 145 (1978) 29-39. 

Sensitivity of detection in LC of sugars is greatly enhanced by the introduction of a fluorescent group, thus permitting the use of fluorimetric detection. A reagent frequently employed for this purpose is 5-dimethylaminonaphthalene-l-sulfonyl hydrazine (dan-syl hydrazine). The reagent solution (1%, m/v, in... 

The identification of N-terminal amino acids in peptides and proteins is of considerable practical importance because it constitutes an essential step in the process of sequential analysis of peptide structures. Many N-amino acid derivatives have been proposed for this purpose and the ones most commonly studied by TLC are 2,4-dinitrophenyl (DNP)-and 5-dimethylaminonaphthalene-l-sulfonyl (dansyl, Dns)-amino acids, and 3-phenyl-2-thiohydantoins (PTH-amino acids). Recently, 4-(dimethylamino)azobenzaie-4/-isothio-cyanate (DABITC) and phenyl-isothiocyanate (PITC) have also been investigated as derivatizing agents of amino acids. 

Synthesis of Calixarenes (1)-(4) Compounds p-5,ll,17,23-tetranitro-25,26,27,28-tetrahydroxy-calix[4]arene, (1), and 4,6,10,12,16,18,22,24-octahydroxy-2,8,14,20-tetraethyl-calix[4]resorcinarene, (2), were prepared in-house following procednres described elsewhere [37]. Compoimd 5,ll,17,23-tetra-A /s-(Af-methylmor-pholine)-25,26,27,28-tetrahydroxy-calix[4]arene, (3), was prepared by adapting the procednre described by Pandey [51]. Compoimd 5,ll,17,23-tetranitro-25,26,27,28-tetra(Af-(5-dimethylaminonaphthalene-l-sulfonyl))-cahx[4]arene, (4), was synthesized according to the reported literatnre procedure [52]. 

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