• 한국식품영양학회지
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• 제5권1호
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• pp.23-32
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• 1992

Kinetic studies of nucleophilic substitution reactions of dansyl, bansyl, dabsyl chlorides with pyridines have been investigated at $0^{\circ}C$ in a range of methanol-acetonitrile binary solvent mixtures. The order of magnitude for reactivity of substrates with pyridines in the same reaction condition is dabsyl chloride>dansyl chloride> bansyl chloride. The value of $\rho$n(-2.29~ -4.66) and $\beta$(0.537~0.901) associated with a change substituent in the nucleophile are large and indicate a relatively advanced bond formation in the transition state. Solvatochromic correlations were predicted the increase of bond formation transition state according to the increasing MeCN contents, showing the greater contribution of polarity polarizability ($\pi$*) than hydro-gen bond donar acidity($\alpha$). We conclude that the reactions of dansyl, bansyl, dabsyl chlorides with pyridines proceed via associative Sn2 type reaction mechanism.

• Bulletin of the Korean Chemical Society
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• 제13권4호
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• pp.395-398
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• 1992

Rate of solvolysis of dansyl chloride in aqueous binary mixtures of acetone, methanol and ethanol are reported. Kinetic solvent isotope effects in methanol and product selectivities in alcohol-water mixtures are also reported. Kinetic data are interpreted with the Grunwald-Winstein and Kivinen equations. The value of $k_{CH3OH}/k_{CH3OD}=1.76$ suggests that a general have catalyzed and/or an $S_AN$ pathway is operative in methanol, a less polar solvent. Rate-rate profiles for solvolysis of dansyl chloride in the aqueous binary media indicate a change in reaction channel from $S_AN$ (in less polar media) to $S_N2$ (in more polar media) mechanism.

• Bulletin of the Korean Chemical Society
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• 제6권3호
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• pp.162-164
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• 1985

Nucleophilic substitution reaction of dansyl chloride with anilines in various solvents have been investigated. The Bronsted ${\beta}$ and Hammett ${\rho}_N$ values indicated that the bond formation is advanced more than the bond breaking at the transition state. Solvatochromic correlations also predicted the importance of bond formation at the TS, showing a greater contribution of polarity (${\pi}^{\ast}$) compared to hydrogen bond donor acidity (${\alpha}$). The effect of solvent on rate was found to violate the reactivity-selectivity principle.

• BMB Reports
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• 제37권2호
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• pp.260-267
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• 2004

Transducin (T), the heterotrimeric guanine nucleotide binding protein in rod outer segments, serves as an intermediary between the receptor protein, rhodopsin, and the effector protein, cGMP phosphodiesterase. Labeling of T with dansyl chloride (DnsCl) inhibited its light-dependent guanine nucleotide binding activity. Conversely, DnsCl had no effect on the functionality of rhodopsin. Approximately 2-3 mol of DnsCl were incorporated per mole of T. Since fluoroaluminate was capable of activating DnsCl-modified T, this lysine-specific labeling compound did not affect the guanine nucleotide-binding pocket of T. However, the labeling of T with DnsCl hindered its binding to photoexcited rhodopsin, as shown by sedimentation experiments. Additionally, rhodopsin completely protected against the DnsCl inactivation of T. These results demonstrated the existence of functional lysines on T that are located in the proximity of the interaction site with the photoreceptor protein.

• 대한화장품학회지
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• 제42권4호
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• pp.413-420
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• 2016

하이드록시 산(hydroxy acid, HA)은 피부 각질층에 대한 박리효과로 노화방지와 피부 보습을 높이는데 효과를 보여, 피부 외용제와 화장품으로서 많은 활용을 하고 있다. 그 중에서 가장 효과적으로 빠른 시간 내에 나타나는 각질 박리는 화장품 제형 pH에 의해 효과를 보이는 것으로 많은 보고가 있다. 그러나 pH에 의한 자극, 부작용에 의한 염려로 인해 사용에 많은 어려움이 있다. 본 연구의 목적은 피부 각질층에 (1) 하이드록시 산의 농도와 (2) 종류, (3) pH를 변화시킨 화장품을 인체 피부에 도포하여 각질 박리 효과에 대한 영향을 측정하는 데에 있다. 건강한 성인 22명을 대상으로 하박 내측에 DHA (dihydroxyacetone), DC (dansyl chloride)로 피부 표면 각질을 염색하여, 시험제품을 도포한 뒤 각질박리 효과를 측정하였다. (1) GA (glycolic acid)의 농도에 따라 각질 박리 효과는 농도 의존적으로 증가하는 것으로 나타났다. (2 )하이드록시 산의 종류에 따라 pH를 산성과 중성으로 제조한 제품을 대상으로 각질 박리 효과를 측정한 결과, 중성 pH의 GA는 각질 박리 효과가 나타나지 않았다. 이에 반해 SA (salicylic acid)는 산성 pH와 중성 pH에서 모두 통계적으로 유의한 각질 박리 효과가 나타났다. (3) 중성 pH의 SA는 DHA와 DC로 염색한 피부 표면에서 모두 우수한 각질 박리 효과를 나타내었다. 이러한 결과는 pH에 민감한 사람들에게 각질 박리 효과를 기대하는 화장품을 사용할 수 있는 기회를 제공하며, 피부 장벽의 손상 없이 안전한 화장품을 제조할 수 있을 것이라 사료된다.

• 대한환경공학회지
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• 제28권2호
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• pp.223-228
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• 2006

본 연구에서는 fluorescence derivatization 기법과 HPLC를 이용하여 수중에 nanograms per liter로 존재하는 극미량 N-nitrosodimethylamine(NDMA)를 분석하고자 하였다. 이를 위해 먼저 다양한 조건 하에서의 fluorescence intensity를 측정함으로써 derivatization 기법을 최적화하였는데, fluorescence detector의 excitation/emission wavelength는 340 nm(excitation)과 530 nm(emission)에서, denitrosation 후 용액의 pH는 9-12의 범위에서, 그리고 dansyl chloride의 농도는 330-500 mg/L 범위에서, 최대 fluorescence intensity를 보여주였다. 용매추출을 통한 수질 시료의 분석에서, 표준농도와 검출농도의 차이는, 저농도(10-200 ng/L) 범위에서 12-162%, 고농도(100-1000 ng/L) 범위에서 6-23%를 보여, 저농도 범위에서 더 많은 차이가 나는 것으로 나타났으나, 두 농도 범위 모두 표준농도와 검출농도의 평균 대비율이 1에 매우 근접해 있어, 수십에서 수백 nanograms NDMA per liter의 분석이 가능함을 보여주었다. 하수처리장 처리수에 주입한 NDMA의 분석에서도 다른 물질에 의한 간섭없이 정확한 농도 검출이 가능했는데, 이는 목적물질을 선별적으로 분석해내는 derivatization 과정에 의한 것으로 나타났다. HPLC와 fluorescence derivatization 기법을 이용한 NDMA의 분석은 상수 및 하수를 사용하는 다양한 실험 연구에서 NDMA를 분석하는 방법으로 효과적으로 사용될 수 있을 것이다.

• Journal of Preventive Medicine and Public Health
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• 제35권4호
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• pp.282-286
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• 2002

Objectives : The level of 4-hydroxyproline (4-Hyp) in human urine was measured using high performance liquid chromatography (HPLC) with a fluorescence detector. This method is useful for medical examinations and investigating the radicals induced by physical, chemical, mental stresses. This method is superior to many published several methods in terms of its low cost and ability to analyze many samples. Methods : The urine from workers in a tire manufacturing company (22 male pre- and post-shift workers) and 18 office-workers as controls were analyzed. Data concerning age, the cumulative drinking amount and the cumulative smoking amount was collected with a questionnaire. The optimum applied amount of dansyl-Cl, the optimum reaction temperature and time, the recoveries and the optimum pH of the eluent and buffer were determined.4-Hyp from human urine was derivatized with dansyl-Cl (dimethylamino-naphthalene-1-sulfonyl chloride) after removing the a-amino acid by a treatment with phthalic dicarboxaldehyde (OPA) and cleaned with Bond Elut C18 column. The 4-Hyp derivatives were separated on a reversed phase column by gradient elution with a phosphate buffer (5 mmol, pH 8.0) and acetonitrile, and detected by fluorescence measurements at 340 nm (excitation) and 538 nm (emission). Results : The detection limit for the urinary free 4-Hyp was $0.364{\mu}mol/l$. The recovery rate of 4-Hyp was 99.7%, and the effective pH of the phosphate buffer and borate buffer were 3.0 and 8.0, respectively. From statistical analysis, age, drinking and smoking did not affect the urinary free 4-Hyp in both the controls and workers. The range of urinary 4-Hyp in the controls, pre-shift, and post-shift workers were 0.33-16.44, N.D-49.06, and $0.32-56.27{\mu}mol/l$. From the pared-sample t-test, the urinary 4-Hyp levels in post-shift workers ($11.82{\pm}6.73\;nmmol/mg\;Cre$) were 2-fold higher than in pre-shift workers ($5.36{\pm}5.53\;nmol;/mg\;Cre$) and controls ($4.91{\pm}4.89\;nmol;/mg\;Cre$). Conclusions : This method was developed with high sensitivity, accuracy, and precision. The present method was effectively applied to analyze the urinary free 4-Hyp in both controls and workers.

• 한국식품영양과학회지
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• 제22권6호
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• pp.815-822
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• 1993

This experiment was carried out to determine the separation condition of 1-dimethylaminonaphthalene-5-sulfony(Dansyl) derivatives of amino acids by reverse-phase high performance liquid chromatography with Nova-Pak C18 column. Determined solvent system was solvent A(200mA phosphate buffer pH 6.8 15%, acetonitrile 11%, water 74%) and solvent B(acetonitrile 65%, methanol 28%, water 7%). Linear gradient of solvent B was applied from 12% to 80% for 50min. Complete separation of 20 amino acids including asparagine and glutamine which constitute protein was achieved within 50min. As the detection limit was the range of picomole, the resolution power was excellent. Reproducibility of the retention time was less than mean $\pm$0.05min. According to the above optimum chromatographic conditions, the amino acid composition of some food and human blood was examined. The most affluent amino acid was alanine in human blood, aspartic acid and glutamic acid in soy sauce, alanine and threonine in soy milk and proline in milk and yoghurt.

• 대한화학회지
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• 제39권4호
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• pp.257-265
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• 1995

시중에 시판되고 있는 우유를 전처리하여 이 우유에 포함된 유리 아미노산을 dansyl-chloride로 유도체화시켜 C-18 컬럼을 이용한 역상 LC법으로 분리한 다음 표준물 첨가법으로 정량했다. 미량의 D-아미노산의 분리에서는 LC의 Column-Switching System을 이용하였으며 비키랄 컬럼을 통과한 단실 D/L-아미노산에 $Cu(N-benzyl-L-proline)_2$를 이동상에 첨가한 키랄 분리를 수행하여 L-아미노산에서 D-아미노산을 분리 정량했다. 이 방법은 우유시료 중에 존재하는 16가지 아미노산의 정량이 가능하며 이중에 12가지의 D-아미노산이 column switching 방법을 통한 키랄 분리로 정량이 가능하다. 우유 100 mL에 총 유리 아미노선이 41.00 mg 포함되어 있음을 확인했으며, D-아미노산은 D-glutamic acid가 2.05%, D-alanine 2.93%만이 포함되어 있음을 확인했다.

• Rapid Communication in Photoscience
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• 제2권1호
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• pp.24-27
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• 2013

A polymeric photobase generator containing oxime-urethane groups is applied to a fluorescence micropatterning material. Polymer bearing oxime-urethane groups was prepared by copolymerization of methyl methacrylate with methacryloyloxyethyl benzophenoneoxime urethane (MBU). The reaction of amino groups in the irradiated copolymer film with dansyl chloride (Dns-Cl) was monitored by using UV absorption, IR absorption and fluorescence spectroscopy. The fluorescence spectrum of the Dns-Cl-treated irradiated copolymer film shows a strong fluorescence with a fluorescence maximum wavelength at 510 nm. A blue fluorescent micropattern with a line width of $2{\sim}3{\mu}m$ was obtained. Treatment of the irradiated copolymer film with Dns-Cl and rhodamine B mixture led to the formation of green, red, and orange-colored fluorescence micropatterns. Thus, various colored micropatterns on a single polymer film can be obtained by selective excitation of each dye molecules.