- Photolysis of the sulfonamide bond of metal complexes of N-dansyl-1,4,7,10-tetraazacyclododecane in aqueous solution: A mechanistic study and application to the photorepair of cis,syn-cyclobutane thymine photodimer
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Sulfonamide constitutes a ubiquitous functional group that is frequently used in organic chemistry, analytical chemistry, and medicinal chemistry. We report herein on the photolysis of a dansylamide moiety of 1-dansyl-1,4,7,10- tetraazzacyclododecane (Nda
- Aoki, Shin,Tomiyama, Yumiko,Kageyama, Yoshiyuki,Yamada, Yasuyuki,Shiro, Motoo,Kimura, Eiichi
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- Effect of prolonged exposure to organic solvents on the active site environment of subtilisin Carlsberg
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The potential of enzyme catalysis as a tool for organic synthesis is nowadays indisputable, as is the fact that organic solvents affect an enzyme's activity, selectivity and stability. Moreover, it was recently realized that an enzyme's initial activity is substantially decreased after prolonged exposure to organic media, an effect that further hampers their potential as catalysts for organic synthesis. Regrettably, the mechanistic reasons for these effects are still debatable. In the present study we have made an attempt to explain the reasons behind the partial loss of enzyme activity on prolonged exposure to organic solvents. Fluorescence spectroscopic studies of the serine protease subtilisin Carlsberg chemically modified with polyethylene glycol (PEG-SC) and inhibited with a dansyl fluorophore, and dissolved in two organic solvents (acetonitrile and 1,4-dioxane) indicate that when the enzyme is initially introduced into these solvents, the active site environment is similar to that in water; however prolonged exposure to the organic medium causes this environment to resemble that of the solvent in which the enzyme is dissolved. Furthermore, kinetic studies show a reduction on both Vmax and KM as a result of prolonged exposure to the solvents. One interpretation of these results is that during this prolonged exposure to organic solvents the active-site fluorescent label inhibitor adopts a different binding conformation. Extrapolating this to an enzymatic reaction we argue that substrates bind in a less catalytically favorable conformation after the enzyme has been exposed to organic media for several hours.
- Bansal, Vibha,Delgado, Yamixa,Fasoli, Ezio,Ferrer, Amaris,Griebenow, Kai,Secundo, Francesco,Barletta, Gabriel L.
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- Synthetic method of dansyl chloride for preparing fluorescent probe (by machine translation)
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The preparation method comprises the following steps: dissolving rhodamine sulfonic acid in an organic solvent to obtain an emulsion; sequentially dropwise adding thionyl chloride and phosphorus pentachloride into the suspension; controlling the temperature of the system to 40 - 45 °C; reacting 4 - 6h; adjusting pH to 5 - 6; and collecting the product to obtain the folic acid chloride. The invention further discloses a fluorescent probe prepared from the dansyl chloride. In the synthesis process of the target fluorescent compound, by adding the phosphorus pentachloride catalyst, the use amount of thionyl chloride is reduced, the reaction condition is mild, and the method can be carried out at a lower temperature. (by machine translation)
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Paragraph 0029-0035
(2020/07/14)
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- Preparation method of 6-deuterated dansyl chloride
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The invention belongs to the technical field of isotope derivatization reagent preparation, and particularly relates to a preparation method of 6-deuterated dansyl chloride. According to the preparation method, 6-deuterated dansyl chloride can be prepared from reaction raw materials including 5-amino-1-naphthalene sulfonic acid, sodium hydride, deuterated methyl iodide, phosphorus oxychloride andphosphorus pentachloride. The preparation method has the advantages of easily available raw materials, low toxicity, few intermediate products and high yield.
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Paragraph 0076-0078
(2020/12/14)
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- Dual signaling of thallium(III) ions via oxidative cleavage of a sulfonhydrazide linkage
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The thallium is widely used in various research and industrial applications but is very toxic. In this work, we developed a novel reaction-based dual signaling probe for the selective and sensitive determination of Tl3+ via the oxidative cleavage of a rhodamine–dansylhydrazide conjugate. The designed probe showed pronounced colorimetric and fluorescence signaling behavior toward Tl3+ with a detection limit of 1.3 × 10–7 M (0.027 ppm), as well as selectivity over other common metal ions, anions, and oxidants. The Tl3+ signaling process required less than 2 min and was not influenced by the solution pH within the range of 4.0–5.5; however, the signal diminished significantly above pH 6.0. To demonstrate the practical applicability of the designed probe, a simple and convenient colorimetric assay for the determination of Tl3+ in commercial reagents was established using an office scanner as a readily available signal capturing device.
- Ahn, Sangdoo,Chang, Suk-Kyu,Choi, Myung Gil,Lee, Yu Jeong,Park, Tae Jung,Yoo, Jae Hoon
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- A N-(2-aminophenyl)-5-(dimethylamino)-1-naphthalenesulfonic amide (Ds-DAB) based fluorescent chemosensor for peroxynitrite
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A dansyl derivative (Ds-DAB) was prepared and used as a fluorescent probe for peroxynitrite (ONOO-) detection. The results showed that the addition of peroxynitrite to the aqueous solution of Ds-DAB would result in obvious fluorescence enhancement. This probe is highly specific for peroxynitrite in aqueous solution, avoiding interference from other reactive oxygen species (ROS) and nitrogen species (RNS). The advantages of high selectivity, fast reaction rate, and peroxynitrite bioimaging render Ds-DAB suitable for peroxynitrite detection.
- Lin, Ku-Kuei,Wu, Shou-Cheng,Hsu, Kuang-Mei,Hung, Chen-Hsiung,Liaw, Wen-Feng,Wang, Yun-Ming
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supporting information
p. 4242 - 4245
(2013/09/12)
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- A trifluoroacetic acid-labile sulfonate protecting group and its use in the synthesis of a near-IR fluorophore
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Sulfonated molecules exhibit high water solubility, a property that is valuable for many biological applications but often complicates their synthesis and purification. Here we report a sulfonate protecting group that is resistant to nucleophilic attack but readily removed with trifluoroacetic acid (TFA). The use of this protecting group improved the synthesis of a sulfonated near-IR fluorophore and the mild deprotection conditions allowed isolation of the product without requiring chromatography.
- Pauff, Steven M.,Miller, Stephen C.
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supporting information
p. 711 - 716
(2013/02/25)
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- The 2-Dansylethoxycarbonyl (=2-{[5-dimethylamino)naphthalen-1-yl]sulfonyl}ethoxycarbonyl; Dnseoc) group for protection of the 5'-hydroxy function in oligodeoxyribonucleotide synthesis
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Use of the 2-dansylethoxycarbonyl (=2-{[5-(dimethylamino)naphthalen-1-yl]sulfonyl])ethoxycarbonyl; Dnseoc) group as an intermediate 5'-OH protecting group in oligodeoxyribonucleotide synthesis using the automated phosphoramidite approach is described in a model study to an alternative strategy in RNA synthesis.
- Bergmann,Pfleiderer
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p. 203 - 215
(2007/10/02)
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- Photochemical Dissociation of p-Nitrobenzyl Sulfonate Esters via an Intramolecular Electron Transfer
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The photochemistry of p-nitrobenzyl sulfonate esters, p-nitrobenzyl 5-dimethylaminonaphthalene-1-sulfonate (NDS) and p-nitrobenzene pyrene-1-sulfonate (NPS) has been investigated by both steady-state and laser flash photolysis techniques.These sulfonates are photochemically dissociated to give the parent sulfonic acids.Quantum yields for photodissociation of NDS and NPS with excitation at 365 nm in degassed acetonitrile solution are 0.20 +/- 0.05 and 0.16 +/- 0.04, respectively.Photodissociation of these sulfonates is considered to proceed via an intramolecularelectron transfer from the excited singlet state of the 5-dimethylaminonaphthalene or pyrene moiety to the p-nitrobenzyl moiety from the fact that the transient absorption bands at 390 and 550 nm due to the radical cation of the 5-dimethylaminonaphthalene moiety, 420 and 450 nm due to the radical cation of the pyrene moiety, and at 340 nm due to the radical anion of the p-nitrobenzyl moiety are detected in laser spectroscopy.Intramolecular-electron-transfer-induced bond cleavage is observed at the oxygen-carbon bond of these sulfonate esters, producing the organic strong acids.Although photodissociation of o-nitrobenzyl esters of carboxylic and sulfonic acids is known, that of p-nitrobenzyl esters has not been previously reported.From the mechanistic point of view, the photochemical behaviour of these p-nitrobenzyl sulfonate esters is quite different from that of o-nitrobenzyl esters.While the latter involves a photoinduced intramolecular rearrangement, the former involves a photoinduced intramolecular electron transfer.
- Naitoh, Kazuhiko,Yamaoka, Tsuguo
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p. 663 - 670
(2007/10/02)
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- ARYL-VINYLSULFONE--REAGENTIEN ZUM SCHUTZ UND NACHWEIS VON THIOLFUNKTIONEN
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Aryl vinyl sulfones selectively react with thiol groups to acid-stable compounds which easily are cleaved by mild bases to thiol compounds.Ester and amide groups are not attacked under these conditions.Therefore, these compounds are good protecting groups or labels in peptide chemistry.The following aryl vinyl sulfones were investigated: phenyl vinyl sulfone 1, p-carbethoxyphenyl vinyl sulfone 15 and the fluorescent 5-dimethylaminonaphthyl 1-vinyl sulfone 5 and 5-methoxynaphthyl-1 vinyl sulfone 10.The last two compounds are very useful reagents for the quantitative determination of SH-groups in polypeptides such as enzymes.
- Horner, L.,Lindel, H.
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