• Journal of Korean Society for Atmospheric Environment
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• 제19권E2호
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• pp.75-81
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• 2003

Variational data assimilation, which is recently introduced to the air quality modeling, is a promising tool for obtaining optimal estimates of initial conditions and other important parameters such as emission and deposition rates. In this paper. two advanced techniques for variational data assimilation, based on the adjoint and quasi-inverse methods, are tested for a simple air quality problem. The four-dimensional variational assimilation (4D-Var) requires to run an adjoint model to provide the gradient information in an iterative minimization process, whereas the inverse 3D-Var (I3D-Var) seeks for optimal initial conditions directly by running a quasi -inverse model. For a process with small dissipation, I3D-Vu outperforms 4D-Var in both computing time and accuracy. Hybrid application which combines I3D-Var and standard 4D-Var is also suggested for efficient data assimilation in air quality problems.

• 한국자원식물학회지
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• 제9권1호
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• pp.55-62
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• 1996

The caffeic acid, 4-O-$\beta$-D-glucopyranosyl caffeic acid, 4-O-$\beta$-D-glucopyranosyl-$\rho$-coumaric acid and 7-O-$\beta$-D-glucuronide of ($\pm$)-eriodictyol have been isolated from the root of Vitis thunbergii var. sinuata. The structures of compounds were determined by chemical and spectroscopic methods.

• Archives of Pharmacal Research
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• 제20권3호
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• pp.291-296
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• 1997

The studies were carried out to evaluate the constituents in the aerial part of Isodon excisus var. coreanus (Labiatae). From the aqueous fraction of methanol extract, compound I (${\alpha}$-[[3-(3, 4-dihydroxyphenyl)-1-oxo-2-propenyl]oxy]-3,4-dihydroxy-benzenepropanoic acid), compound II (9-methyl-dihydroferulic acid-4-O-.betha.-D-glucopyranosyl $(1{\rightarrow}2)$-${\alpha}$-L- rhamnopyranosyl (1.rarw.4)-.betha.-D-glucopyranoside), compound III (ent-7.alpha., 11${\alpha}$,15.betha.-trihydroxy-kaur-16-en-1-O-.betha.-D-glucopyranoside) and compound IV ($2{\alpha}$,3${\beta}$,$7{\alpha}$,23-tetrahydroxy-olean-12 -en-28-oic acid 28-O-${\beta}$-D-glucopyranoside) were isolated and identified on the basis of their physicochemical and spectroscopic evidences[IR, FAB(-)MS,$^{1}H-NMR,$$^{13}C-NMR,$$ HMQC$$^{1}H-^{1}H $COSY and HMBC (Heteronuclear Multiple Bond Connectivity)]. Especially, New compounds II and III were named Isodonin A and Isodonin B respectively.

• 생약학회지
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• 제33권1호통권128호
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• pp.1-4
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• 2002

The phytochemical study of the underground parts of Gardenia jasminoides var. radicans Makino (Rubiaceae) led to the isolation of five coumarins. On the basis of spectroscopic evidences, the structures of these compounds were charaterized as ferulic acid(l), 5,8-di-(3-methyl-2,3-dihydroxybutyloxylpsoralen)(2), skimmin(3), uracil(4), $3-0-{\alpha}-D-glucopyranosyl-(1{\rightarrow}4)-{\beta}-D-glucopyranosyloxypeucedanin$ hydrates(5), respectively.

• 생약학회지
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• 제53권1호
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• pp.16-20
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• 2022

Five ent-kaurane type diterpene glycosides were isolated from the aerial parts of Inula britannica var. chinensis Regel (Compositae) through repeated column chromatography. Their chemical structures were elucidated as 16β-H-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (1), 16β-hydroxy-17-acetoxy-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (2), 16β,17-dihydroxy-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (3), 16α,17-dihydroxy-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (4) and 17-O-β-D-glucopyranosyl-16β-H-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (5), respectively, by spectroscopic analysis. Among these compounds, 1-4 were isolated for the first time from this plant.

• Applied Microscopy
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• 제24권4호
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• pp.13-31
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• 1994

피자식물내 엽육조직 미세구조연구의 일환으로 형태해부학적으로 매우 다른 특성을 지닌 국화과 Dubautia속 식물 3종(Dubautia scabra var. leiophylla, D. knudsenii, D. scabra var. leiophylla, D. knudsenii)의 엽육조직이 연구되었다. 부모종 엽육조직의 형태해부학적 특성과 그들의 잡종 엽육조직세포의 분화 정도를 추정하기 위하여 palisade mesophyll내의 chloroplasts, microbodies, mitochondria 및 grana내의 thylakoid membrane system, phytoferritin-like structures, plastoglobuli와 starch grain 등 엽록체 내부의 초미세구조 형질들을 중점적으로 비교 분석하였다. 잡종의 엽육조직세포들은 형태해부학적 엽육형질 및 thylakoidal membrane system 등의 형질에서 부모종 엽육조직의 중간적 특성 (intermediacy)을 나타내어 전형적인 bilateral inheritage를 보여주었으며, thylakoid membrane number/granum, phytoferritin-like structures, starch grain의 분포 등에서는 어느 한 부모종 형질과 더 유사하게 관찰되었다. 미소체 및 미토콘드리아는 대체로 비슷한 양상으로 관찰되었고 phytoferritin-like structures는 국화과 식물 엽록체내에서 처음 보고되는 미세구조이다.

• Preventive Nutrition and Food Science
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• 제6권3호
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• pp.137-141
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• 2001

Water-soluble crude polysaccharide (TM-1) prepared from the leaves of Teucrium viscidum var. miquelianum was fractionated into three polysaccharide fractions, TM-2, TM-3 and TM-4 by the addition of cetyltrimethylammonium bromide. The major polysaccharide fraction, TM-2, consisted of glucose, galactose, rhamnose, mannose, glucuronic acid and galacturonic acid, and all fractions contained galactose and glutose as the major neutral sugars. TM-4 showed the highest anti-complementary activity. When TM-4 was futher fractionated by anion exchange chromatography, TM4- II a and TM4-II b showed the most Potent anti-complementary activity. TM4- II a was composed mainly of galactose, arabinose and glucose in the molar ratios of 2.13 : 0.94 : 1.00 respectively, and contained a small amount of galacturonic acid and glucuronic acid.

• Natural Product Sciences
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• 제17권4호
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• pp.261-266
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• 2011

During the process of screening for antioxidative effects of natural plants in Korea, by measuring the superoxide quenching activity, methanol extract of the whole plant, Galium verum var. asiaticum (Rubiaceae), was found to show potent antioxidant activity. Subsequent activity-guided fractionation of methanol extract of Galium verum var. asiaticum led to the isolation of five phenolic compounds. Using spectroscopic techniques, the chemical structures were elucidated as: caffeic acid (1), narcissin (2), rutin (3), luteolin-7-O-${\alpha}$-L-rhamnopyranosyl (1 ${\rightarrow}$ 2)-${\beta}$-D-glucopyranoside (4), and luteolin-7-O-${\beta}$-D-glucopyranoside (5). These compounds were isolated for the first time from this plant. Among them, compound 1 showed the most significant riboflavin-originated superoxide and xanthine-originated superoxide quenching activities. Compounds 3 and 4 exhibited mild superoxide quenching effects compared with vitamine C.

• The Korean Journal of Ecology
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• 제21권4호
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• pp.345-349
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• 1998

thirteen dictyostelid cellular slime molds were isolated from forest soils, cattle dung and manure inisland Ulneungdo, South Korea. They were ten species including Dictyostelium aureo-stipes var. aureo-stipes, D. brefeldianum, D. macrocephalum, D. caudabasis, D. sphaerocephalum, D. giganteum, D. crassicaule, Polysphondylium pallidum, P. violaceum and P. tenuissimum as well as three species unidentified. D. aureo-stipes var. aureo-species of genus Polysphondylium distributed widely. It was thought that species diversi쇼 was considerabley higher.

• Archives of Pharmacal Research
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• 제14권2호
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• pp.124-129
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• 1991

One new triterpenoidal bisdesmoside, saponin C (3) were isolated from the leaves of Kalopanax pictum var. chinense along with two known saponins, saponin B (2, sapindoside C) and saponin A (1, sapoindoside B). On the basis of chemical and spectral evidences, the structure of a new triterpenoidal saponin has been elucidated to be 3-O-$\beta$-D-glucopyranosyl (1$\rightarrow$4)$\beta$-D-xylopyranosyl (1$\rightarrow$3)-$\alpha$-L-rhamnopyranosyl (1$\rightarrow$2)-$\alpha$-L-arabino-pyranosyl-23-hydroxyolean-12-en-28-O-$\alpha$-L-rhamnopyrano syl (1$\rightarrow$4)-$\beta$-D-glucopyranosyl (1$\rightarrow$6)-$\beta$-D-glucopyranosyl ester.