• Natural Product Sciences
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• v.18 no.3
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• pp.195-199
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• 2012

Nine iridoid glycoside derivatives were elucidated from the methanolic extract of the aerial parts of Galium spurium (Rubiaceae) through repeated column chromatography. Their chemical structures were characterized as 10-O-trans-p-coumaroylscandoside (1a), 10-O-cis-p-coumaroylscandoside (1b), 10-O-trans-p-coumaroyl-10-O-deacetyldaphylloside (2), 10-O-cis-p-coumaroyl-10-O-deacetyldaphylloside (3), asperulic acid methylester (4), asperuloside (5), asperulosidic acid (6), scandoside (7), and deacetyl asperulosidic acid (8) by spectroscopic analysis. This is the first report of the characterization of compounds 1a, 1b, 2, 3 and 7 from this plant.

• Korean Journal of Pharmacognosy
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• v.36 no.3 s.142
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• pp.191-194
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• 2005

Four compounds were isolated from the twigs of Vaccinium oldhami (Ericaceae) through repeated column chromatography. Their chemical structures were elucidated as (+)-catechin, (-)-epicatechin, proanthocyanidin A-2, and cinnamtannin $B_1$, respectively, by spectroscopic analysis.

• Bulletin of the Korean Chemical Society
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• v.22 no.11
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• pp.1207-1212
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• 2001

A new photochemically bifunctional epoxy and dimethacrylate compounds were synthesized for investigating the photosensitivity under UV irradiation. Photosensitivity of the synthesized chalcone-based compounds was investigated by using UV-visible absorption and Fourier transformed infrared (FT-IR) spectroscopies. The result of spectroscopic analysis substantiated that the two chalcone-based compounds have functions of both photocrosslinking and photopolymerization by UV exposure in the presence of photoinitiator. Two kinds of photochemical reactions proceeded competitively during UV exposure. Particularly, we studied the effect of photopolymerization on the rate of photocrosslink due to cycloaddition in the two oligomeric compounds.

• Journal of the Korean Chemical Society
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• v.65 no.6
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• pp.489-494
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• 2021

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.200.4-201
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• 2003

Ten compounds were isolated from the methanolic extract of the whole plants of Diodia teres through repeated silica gel and Sephadex LH-20 column chromatography. Their chemical structures were elucidated as three iridoid glycosides, a coumarin glycoside, and six flavonoids by spectroscopic analysis. These compounds were isolated for the first time from D. teres.

• Near Infrared Analysis
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• v.1 no.1
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• pp.23-26
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• 2000

The objectives of this study were to examine the ability to predict soluble solid and firmness in intact apple based on the visible/near-infrared spectroscopic technique. Two cultivars of apples, Delicious and Gala, were handled, tested and analyzed. Reflectance spectra, Magness-Taylor (MT) Firmness, and soluble solids in apples were measured sequentially. Maximum and minimum diameters, height, and weight of apples were recorded before the MT firmness tests. Apple samples were divided in to a calibration set and a validation set. The method of partial least squares (PLS) analysis was used. a unique set of PLS loading vectors (factors) was development for soluble solid and firmness. The PLS model showed good relationship between predicted and measured soluble solids in intact apples in the wavelength range of 860∼1078 nm. However, the PLS analysis was not good enough to predict the apple firmness.

• Korean Journal of Pharmacognosy
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• v.32 no.4 s.127
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• pp.322-326
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• 2001

For the quality control of Leonuri Herba, alkaloid compound, leonurine, was isolated from the MeOH extract of Leonurus sibiricus L. (Labiatae) and identified by the spectroscopic analysis. A quantitative analysis of leonurine using HPLC method showed that the average contents were $0.124{\pm}0.065%$ in 34 samples collected throughout the regions of Korea.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.389-398
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• 2011

Although the currently available surface spectroscopic techniques provide powerful means of studying atoms and simple molecules on surfaces, the identification of complex molecules and functional groups is a major concern in surface analysis. This article describes a recently developed method of surface molecular analysis based on reactive ion scattering (RIS) of low energy (< 100 eV) $Cs^+$ beams. The RIS method can detect surface molecules via a mechanism in which a $Cs^+$ projectile picks up an adsorbate from the surface during the scattering process. The basic principles of the method are reviewed and its applications are discussed by showing several examples from studies of molecules and their reactions on surfaces.

• Korean Journal of Pharmacognosy
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• v.32 no.2 s.125
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• pp.157-162
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• 2001

For the quality control of Cassiae Semen, anthraquinone compound, aurantio-obtusin, was isolated from the MeOH extract of Cassiae Semen (Leguminosae) and identified by the spectroscopic analysis. A quantitative analysis of aurantio-obtusin using HPLC method showed that the average contents of aurantio-obtusin were $0.03{\pm}0.01%$ in 50 samples collected throughout the various regions of Korea.

• Journal of IKEEE
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• v.20 no.4
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• pp.337-343
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• 2016

This study conducted the gamma ray spectroscopic analysis of the microcolumnar CsI:Tl deposited onto the SiPMs using thermal evaporation deposition. The SEM measured thickness of microcolumnar CsI:Tl and of its individual columns. From the SEM observation, the measured thickness of CsI:Tl were $450{\mu}m$ and $600{\mu}m$. The gamma ray spectroscopic properties of microcolumnar CsI:Tl, $450{\mu}m$ and $600{\mu}m$ thick deposited onto the SiPMs were analyzed using standard gamma ray sources $^{133}Ba$ and $^{137}Cs$. The spectroscopic analysis of microcolumnar CsI:Tl deposited onto the SiPMs included the measurements of response linearity over the $^{137}Cs$ gamma ray intensity; and gamma ray energy spectrum. Furthermore from the gamma ray spectrum measurement of $^{133}Ba$ and $^{137}Cs$, $450{\mu}m$ thick CsI:Tl showed good efficiency when measured with $^{133}Ba$ and $600{\mu}m$ thick CsI:Tl was highly efficient when measured with $^{137}Cs$.