• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.793-799
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• 2011

We report the complexation behavior of calix[4]arenemonoquinone-triacid (CTAQ), which is an electroactive and water-soluble receptor for calcium ion. UV-visible and NMR spectroscopic studies revealed that CTAQ in aqueous media forms 1:2 as well as 1:1 (metal ion:CTAQ) stoichiometric complexes with $Ca^{2+}$, $Sr^{2+}$, and $Ba^{2+}$ ions. The nonlinear fitting of titration curves based on UV-visible absorption spectra showed that the binding constants of CTAQ for $Ca^{2+}$ ion are 4 $({\pm}2){\times}10^6\;M^{-1}$ for 1:1 and 1.4 $({\pm}0.5){\times}10^{11}\;M^{-2}$ for 1:2 complex. NMR conformational studies and the titration curves corroborate that the $Ca^{2+}$:CTAQ complex in aqueous solution is not present in the form of merely 1:1 one, being consistent with UV-visible spectrophotometric results. The Monte Carlo simulation supports the presence of a stable conformer of 1:2 complexes in which a $Ca^{2+}$ ion is interposed between two CTAQs at the global minimum. This is the first model of 1:2 stoichiometric complex of calix[4]arene and alkaline earth ions in aqueous media.

• 박물관보존과학
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• 제14권
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• pp.81-89
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• 2013

본고는 우리나라 청색계 염재인 쪽과 황색계 염재인 울금, 치자, 황련, 황벽으로 염색한 청색, 녹색계열의 직물편에 대한 비파괴 자외-가시광 분광 분석 및 3차원 형광 분광 분석 내용이다. 직물의 종류에 따라 각 염재의 분석결과에 영향을 주는지 여부를 확인하기 위하여 견과 면에 염색한 직물시편을 제작하였다. 염색 직물편에 대한 자외-가시광 반사도 측정 결과 쪽으로 염색한 경우 직물의 종류에 관계없이 쪽의 고유한 반사 스펙트럼이 나타났다. 녹색 계열의 직물은 3차원 형광 분광 분석결과 직물의 영향없이 황색 염재인 울금, 황련 및 황벽의 고유한 형광 스펙트럼이 확인되나 치자 및 쪽의 형광 스펙트럼은 나타나지 않았다. 이와 같은 결과는 견이나 면에 염색된 청색 및 녹색 염료의 종류를 규명하는 자료로 활용할 수 있을 것으로 판단된다.

• 대한화장품학회지
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• 제15권1호
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• pp.51-62
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• 1989

Inclusion complex formation of octyldimethl p-aminobenzoate with $\beta$-cyclodextrin in aqueous solution and in the solid state was studied by the solubility method, spectroscopic(UV, FT-lR) and X -ray diffractometry. The solid complex of octyldimethy p-aminobenzoate with $\beta$-cyclodextrin was obtained in molar ratio of 1 : 2(guest/host). A spatial relationship between host and guest molecule was clearly reflected in the magnitude of the apparent stability constant (K') and in the stoichiometry of the inclusion complex. Furthermore, a typical type Bs phase-solubility diagram was obtained for octyldimethyl p-aminobenzoate and p -cyclodextrin in water at $25^{\circ}C$. The results indicated that the solubility of the guest molecule was higher by the formation of $\beta$-cyclodextrin inclusion complex.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1233-1236
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• 2010

2,3-Dichloro-1,4-naphtoquinone 1 compound was reacted with octadecanethiol 2 in two different mole ratio. Compound 3 was obtained from the reaction of 1 and 2 in 1:2 mole/mole ratio. Compounds 7 and 8 were obtained from reaction of 1 and 2 in 1:1 mole/mole ratio and known compound 9 was synthesized as by-product in this reaction. Novel compounds 5a-e were obtained from reaction of 1 and related thiols 4a-e. Known compounds 6c and 6e were synthesized as by-product in this reaction. The structures of the compounds were characterized by elemental analysis, UV-vis, FTIR, $^1H$-NMR, $^{13}C$-NMR and Mass spectroscopies.

• Natural Product Sciences
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• 제24권3호
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• pp.155-158
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• 2018

A new flavonol derivative, meliglabrin (1) along with three known flavonols, ternatin (2), meliternatin (3), and 5,4'-dihydroxy-3,7,3'-trimethoxyflavon (4) were isolated from the leaves of Melicope glabra (Blume) T.G. Hartley. Their structures were determined using extensive spectroscopic methods, including UV, IR, HRESIMS, 1D and 2D NMR. Compounds 1 - 4 were evaluated for their cytotoxicity against murine leukemia P-388 cells, compound 4 showed moderate activity.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.63-66
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• 2004

Transparent MgO thin films were deposited on glass substrates by electron beam evaporation of MgO (99.99%) under $O_2$ atmosphere at 150-250 $^{\circ}C$. These films were characterized for their useful properties such as thickness, transmission, and refractive index using ultraviolet / visible (UV/VIS) spectrophotometer, scanning electron microscopy (SEM), and Spectroscopic Ellipsometry. The thickness of MgO films were measured by alpha step instrument and found to be 600 nm to 1000 nm and are meeting the stoichiometry. The transmission spectrum of these films shows transmittance values ${\sim}$92%..

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
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• pp.47-49
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• 1995

We report the spectroscopic properties of column-III nitrifies of GaN, GaInN, and AlGaN. The column-III nitride semiconductors are promising materials to realize the current-injection-type blue-and ultraviolet (UV)-light-emitting devices with high performance. To acheive the lasing with low threshold, the devices are must constructed to double heterostructure by succesive epitaxial growth technique, and we must confine the carriers in the potential barrier and optical confinement in wave guide between barrier and active layers has different refractive index. The refractive index of column-III nitride semiconductors, however, are rarely reported. The measured refractive index was 2.9, and the observed characteristic peak near the enrgy gap was analysed using a dielectric function and may due to excitonic contribution.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.205-211
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• 2005

Water-soluble polyethyleneimine (PE) derivatives containing nucleic acid bases and hydrophilic amino acids such as homoserine (Hse) and serine were prepared by the activated ester method as nucleic acid models. From spectroscopic measurements, the polymers were found to interact with DNA accompanied by an induction of conformational change. Hypochromicity in UV spectra indicated that a stable polymer complex was formed between poly (A) with PEI­Hse-Ura by complementary hydrogen bonding with equimolar nucleic base units (adenine:uracil=1:1). The induced conformation of DNA by the interaction with the polymer containing uracil and homoserine (PEI-Hse-Ura) was concluded to be a super triple helical structure. The formation of the polymer complex, DNA: PEI-Hse-Ura, was found to be affected by the presence of metal ions such as $Ca^{2+}\;and\;Cu^{2+}$.

• 한국작물학회지
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• 제45권2호
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• pp.83-87
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• 2000

The five phenolic compounds of peony root were isolated by Sephadex LH-20 column chromatography. Their chemical structures were identified by spectroscopic methods (UV, FT-IR, FAB-MS and $^1H$ .&^13C$-NMR). The complete structures of these compounds were elucidated to be (+)-taxifolin-3-0-$\beta$-D-glucopyranoside, benzoic acid, gallic acid, (-)-epicatechin and (+)-catechin. The concentrations of five phenolic compounds in the peony root of three Korean cultivars (Youngchonjakyak, Euisungjakyak and Jomjakyak) were determined by reverse-phase HPLC. The constituents concentration in Youngchonjakyak were generally higher than in Euisungjakyak and Jomjakyak. The concentrations of (+)-taxifolin-3-O-$\beta$-D-glucopyranoside, benzoic acid, gallic acid, (-)-epicatechin and (+)-catechin in three different cultivars were ranged 0.23-0.52%, 0.20-0.30%, 0.26-0.28%, 0.09-0.12% and 0.34-0.63%, respectively.

• Natural Product Sciences
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• 제10권2호
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• pp.69-73
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• 2004

Continuation of a phytochemical study of Cichorium intybus L. (Astraceae) growing in Egypt, resulted in the isolation and identification of a new sesquiterpene lactone 3,4-dihydrolactucin, in addition to the eight known compounds; kaempferol, isoscutellarin, cichoriin, umbelliferone, lupeol, lupeol acetate, ${\beta}-sitosterol$, and ${\beta}-sitosterol-3-O-glucoside$. Chemical structures of the isolated compounds were assigned based on different physical, chemical, and spectroscopic techniques including IR, UV, MS, 1D- and 2D-NMR spectra. Furthermore, the antimicrobial, and spasmogenic activities of some fractions and isolates were also assessed.