• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E2
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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.

• Korean Journal of Plant Resources
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• v.9 no.1
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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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• v.20 no.3
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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.

• Korean Journal of Pharmacognosy
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• v.33 no.1 s.128
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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.

• Korean Journal of Pharmacognosy
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• v.53 no.1
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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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• v.24 no.4
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• pp.13-31
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• 1994

The fine structure of palisade chloroplasts has been studied in the mature leaves of 3 Dubautia species (D. scabra var. leiophylla, D. knudsenii and D. scabra var. leiophylla${\times}$D. knudsenii) to explore variation at the ultrastructural level, since the parental species exhibit quite different morphological and anatomical features. Types of thylakoidal membrane systems, occurrence and distribution of phytoferritin-like structures, lipid droplets, starch grains, mitochondria and microbodies were examined. Four different types of thylakoidal membranes were found in D. scabra var. leiophylla, 2 rather uniform types in D. knudsenii and 3 intermediate types in their hybrid. D. scabra var. leiophylla and the hybrid were marked by statistically significant differences in mean numbers of thylakoids per granum, while no significant difference was found between D. knudsenii and the hybrid. Phytoferritin-like structures which were about $100-120{\AA}$ in diameter as a whole particle each were found in all 3 species. The amount and distribution of particles varied by species. Lipid droplets, plastoglobuli, and starch grains occurred in all 3 species, but the frequency of starch grains also varied with the species. More frequent and larger starch grains were observed in D. knudsenii than in the other two species. Microbodies, or peroxisome, were observed throughout all species. They occurred, either with or without crystalline inclusions, around the chloroplasts.

• Preventive Nutrition and Food Science
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• v.6 no.3
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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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• v.17 no.4
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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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• v.21 no.4
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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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• v.14 no.2
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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.