• Journal of Korean Society for Atmospheric Environment
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• v.30 no.1
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• pp.1-17
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• 2014

Temporal variations of optical properties of urban aerosol in Seoul were estimated by the Optical Properties of Aerosols and Clouds (OPAC) model, based on hourly aerosol sampling data in Seoul during the year of 2010. These optical properties were then used to calculate direct radiative forcing during the study period. The optical properties and direct radiative forcing of aerosol were calculated separately for four chemical components such as water-soluble, insoluble, black carbon (BC), and sea-salt aerosols. Overall, the coefficients of absorption, scattering, and extinction, as well as aerosol optical depth (AOD) for water-soluble component predominated over three other aerosol components, except for the absorption coefficient of BC. In the urban environment (Seoul), the contribution of AOD (0.10~0.12) for the sum of OC and BC to total AODs ranged from 23% (spring) to 31% (winter). The diurnal variation of AOD for each component was high in the morning and low in the late afternoon during the most of seasons, but the high AODs at 14:00 and 15:00 LST in summer and fall, respectively. The direct negative radiative forcing of most chemical components (especially, $NO_3{^-}$ of water-soluble) was highest in January and lowest in September. Conversely, the positive radiative forcing of BC was highest in November and lowest in August due to the distribution pattern of BC concentration.

• Journal of Environmental Science International
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• v.28 no.1
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• pp.107-123
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• 2019

The aerosol chemical components in $PM_{2.5}$ in several regions (Seoul, Busan, Daejeon, and Jeju Island) were investigated with regard to their concentration characteristics and optical properties. The optical properties of the various aerosol components (e.g., water-soluble, insoluble, Black Carbon (BC), and sea-salt) were estimated using hourly and daily aerosol sampling data from the study area via a modeling approach. Overall, the water-soluble component was predominant over all other components in terms of concentration and impact on optical properties (except for the absorption coefficient of BC). The annual mean concentration and Aerosol Optical Ddepth (AOD) of the water-soluble component were highest in Seoul (at the Gwangjin site) ($26{\mu}g/m^3$ and 0.29 in 2013, respectively). Further, despite relatively moderate BC concentrations, the annual mean absorption coefficient of BC ($21.7Mm^{-1}$) was highest in Busan (at the Yeonsan site) in 2013, due to the strong light absorbing ability of BC. In addition, high AODs for the water-soluble component were observed most frequently in spring and/or winter at most of the study sites, while low values were noted in summer and/or early fall. The diurnal variation in the AOD of each component in Seoul (at the Gwangjin site) was slightly high in the morning and low in the afternoon during the study period; however, such distinctions were not apparent in Jeju Island (at the Aweol site), except for a slightly high AOD of the water-soluble component in the morning (08:00 LST). The monthly and diurnal differences in the AOD values for each component could be attributed to the differences in their mass concentrations and Relative Humidities (RH). In a sensitivity test, the AODs estimated under RH conditions of 80 and 90% were factors of 1.2 and 1.7 higher, respectively, than the values estimated using the observed RH.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.680-685
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• 2008

In this study, we assessed the functional characteristics of Aralia continentalis Kitagawa (AcK) and Aralia continentalis Kitagawa leaf (AcK-leaf), including crude saponin contents, antioxidant activity, nutritive elements, dietary fiber, and chlorophyll contents. The results of our analysis of nutritive elements in AcK, the contents of the general components, inorganic components, and vitamins were all relatively high. The contents of inorganic components were also high in the following order: K>Ca>P>Na>Mg. Among vitamins, $\beta$-carotene and vitamin C contents were all high. The crude saponin content was 63.7 mg/g in the AcK and 63.5 mg/g in the AcK leaf, and the antioxidant activity was determined to be relatively high. With regard to the dietary fiber content, the total dietary fiber content was 2.13% (soluble 0.40, insoluble 1.72) in the AcK and 5.98% (soluble 1.06, insoluble 4.89) in the AcK leaf, and the total chlorophyll content was 92.58 mg in the AcK and 147.25 mg/100 g in the AcK-leaf.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.279-285
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• 2014

Nutritional composition, including total phenolics, tannins and nutrient components, of acorns of Q. actissima, Q. serrata, Q. variabilis and Q. mongolica were analyzed. Acorns were collected from each tree species, which were grown in a seed orchard. Contents of both total phenolics and tannins in acorns of Q. serrata were higher than those of Q. actissima (p<0.05). Interestingly, Q. serrata contained the highest amount of water soluble tannins (71 mg/g dw) and the lowest levels of water insoluble tannins (8.1 mg/g dw) among 4 oak species, resulting that acorns of Q. serrata had the lowest proportion of insoluble tannins. Among 4 oak species tested, Q. mongolicav acorns contained the highest levels of both total dietary fiber (TDF) and ascorbic acid, while the content of beta-carotene in Q. mongolicav was 52-fold lower than that in Q. variabilis ($520{\mu}g/100g$). Our result showed that nutritional composition of acoms was significantly different between oak species, indicating that tastes or nutritional values might be different as well among major oak species in Korea.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.563-567
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• 2004

Nutritional components, such as approximate compositions, and amino acid, mineral, vitamin, sugar, and fatty acid contents, of artificially cultivated Pleurotus ferulea were analyzed. Contents of carbohydrates, crude lipids, dietary fibers, crude proteins, total amino acids, particularly essential amino acids, minerals, water-insoluble and-soluble vitamins, glucose, and unsaturated fatty acids such as linoleic acid of P. ferulea were higher than those of P. ostreatus and P. eryngii. Results indicate P. ferulea has abundant essential nutrients and thus is good source of functional healthy food.

• Applied Biological Chemistry
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• v.36 no.3
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• pp.154-157
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• 1993

Based upon the antioxidative effectiveness of ether extracts of defated Crataegus pinnatifida B., phenolic antioxidative components were separated by gel column chromatography and identified by MS and H-NMR. Two or three individual compounds were found in free, soluble and insoluble bound phenolic acids, respectively and they were identified as caffeic acid, protocatechuic acid, phloroglucinol and pyrogallol.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.267-271
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• 2000

Abstract Two glucans (PONGa and PONGb) differing in their anomeric and glycosidic linkage structures were isolated from the water-insoluble materials (PON) of Pleurotus ostreatus basidiocarps, which activated the complement system and were almost soley composed of D-glucose. The isolatIon was achieved by repeated precipitations with ethanol and adsorption on concanavalin A (Con A) of paN suspension in thymol/NaCL Based on methylation analysis. IR, GLC-MS, $^1H,{\;}and{\;}^{13}C-NMR$ spectroscopies, PONGa was found to be a branched a-glucan composed of ${\alpha}-linked$ D-glucopyranose residues and ${\alpha}-linked$ units with 6-branching points, whereas PONGb was a linear ${\beta}-1,3-glucan$ composed mainly of ${\beta}-1,3-linked$ D-glucopyranose residues. The PONGb particles reacted more potently than the PONGa particles as C3 activator in alternative complement hemolysis and crossed-immunoelectrophoresis using anti-human C3, thereby suggesting that the complement activating components of PON were ${\beta}-(13)-glucans rather$ than ${\alpha}-glucan$ components.onents.

• Journal of Plant Biology
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• v.31 no.4
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• pp.277-288
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• 1988

The effects of ammonium ion and glutamate on CO2 fixation abilities and related carbon metabolism were investigated in pea (Pisum sativum L. cv. Sparkle) leaf discs under conditions favoring photorespiration (21% O2, 0.03% CO2) and nonphotorespiration (5% O2, 0.03% CO2). A concentration of more than 10 mM of NH4+ decreased the photosynthetic CO2 fixation and those inhibitory effects were more remarkable in 21% O2 than in 5% O2 conditions. The effect of glutamate on CO2 fixation was found to be independent of the O2 level, as glutamate increased the CO2 fixation under both 21% and 5% O2 conditions. L-methionine-dl-sulfoximine, an irreversible inhibitor of glutamate synthetase, however, inhibited the CO2 fixation markedly under 21% O2, but did not affect it under 5% O2 conditions. The treatment with NH4+ elevated the relative amounts of 14C incorporated into soluble components from 14CO2 with no relation to O2 levels, while glutamate increased 14C into insoluble components and neutral sugars. Glutamate, especially, seemed to stmulate the biosynthesis of starch under 5% O2 condition. These results indicated that NH4+ stimulated the degradation of sugar or starch and this proposal was confirmed by the increasing of pyruvate kinase activity in leaf discs treated with ammonium ion.

• Korean Journal of Pharmacognosy
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• v.13 no.4
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• pp.145-152
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• 1982

Three species of genus Polygonum, namely P. cuspidatum, P. sachalinense and P. ellipticum are distributed in Korea. Polygonum ellipticum Migo is a perennial herb in Polygonaceous plants. The root of the plant (Polygoni Rhizoma, 'Ho-jang') have been used as laxative, diuretic and for the treatment suppurative dermatitis in the oriental medicine. As the part of the study for the comparison of the three species in their components, the authors attempted to isolate the anthraquinones and stilbene derivative from the rhizome of P. ellipticum. The methanolic extract of dried rhizome of this plant was fractionated into ether soluble and insoluble fraction and each fraction was applied to column chromatography to isolate above mentioned components. Anthraquinone derivatives were isolated first; comp. I, mp $204{\sim}205^{\circ}$ (physcion), comp. II, mp $254{\sim}255^{\circ}$ (emodin), comp. IV, mp $191{\sim}192^{\circ}$ $(emodin-8-O-{\beta}-D-glucoside)$ and comp. III, mp $280{\sim}282^{\circ}$ $({\beta}-sitosterol-glucoside)$. They were identified by chemical properties and UV, IR and NMR spectra and by the direct comparison with authentic samples. Stilbene derivative was isolated secondly; comp. V, mp $255{\sim}256^{\circ}$ which was reported to possess antibacterial and antifungal activities.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.738-742
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• 1990

Cell wall components were decreased during maturation and postharvest of persimmon fruits. Contents of pectin and alkali-soluble hemicellulose were increased during maturity, but those of acid-soluble hemicellulose were decreased. Contents of pectin and alkali-soluble hemicellulose were decrease in soft persimmon, whereas acid-soluble hemicellulose was increased remarkably. Cellulose contents were increased during maturation and this tend was notable in soft persimmon. Contents of cell wall polysaccharides per 100g-fresh weight were decreased. Contents of total pectin and insoluble pectin were increased during maturation but decreased in soft persimmon. Content of water-soluble pectin was increased during maturation and postharvest.