• Natural Product Sciences
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• 제17권4호
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• pp.279-284
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• 2011

Phytochemical studies on the whole extract of Sedum hybridum L., a Mongolian medicinal plant, has been undertaken to isolate active principles responsible for its anti-oxidative and antibacterial activities. Eighteen known compounds, i.e. (1) quercetin, (2) kaempferol, (3) herbacetin-8-O-${\beta}$-D-xylopyranoside, (4) myricetin, (5) gossypetin-8-O-${\beta}$-D-xylopyranoside, (6) gallic acid, (7) 2,4,6-tri-O-galloyl-D-glucopyranose, (8) 6-O-galloylarbutin, (9) myricetin-3-O-${\alpha}$-L-arabinofuranoside, (10) quercetin-3-O-${\alpha}$-L-arabinofuranoside, (11) caffeic acid, (12) ethylgallate, (13) (-) epigallocatechin-3-O-gallate, (14) palmitic acid, (15) stearic acid, (16) stearic acid ethyl ether, (17) ${\beta}$-sitosterol and (18) ${\beta}$-sitosteryl-O-${\beta}$-D-glucopyranose have been isolated and their molecular structures identified by spectroscopic analysis. Thirteen substances including seven flavonol components (1, 2, 3, 4, 5, 9 and 10), five gallic acid derivatives (6, 7, 8, 12 and 13) and caffeic acid (11) exhibited significant, dose-dependent, DPPH radical scavenging activity. Galloyl esters 12 and 13 were revealed to be main active principles for the antibacterial property of the extract of Sedum hybridum L.

• Archives of Pharmacal Research
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• 제29권4호
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• pp.298-301
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• 2006

This study was investigated the bactericidal effects of calcium oxide (CaO) on three common foodborne pathogenic bacteria: Escherichia coli, Listeria monocytogenes, and Salmonella typhimurium. Each bacteria level was determined in a CaO solution (0.01, 0.03, 0.05, 0.10, 0.15, and $0.20\%$ [w/v]) exposed for either 15 sec, 30 sec, 1 min, 2 min, 3 min, 5 min, 10 min, or 30 min. All three bacteria were not greatly affected by CaO solutions at concentrations of 0.01 and $0.03\%$, however, the decline of E. coli $(99\%;\;2.78\;log_{10}CFU/mL)$, L. monocytogens $(45\%;\;1.44\;log_{10}CFU/mL)$, and S. typhimurium $(70\%;\;2.08\;log_{10}CFU/mL)$ was greatest when they were exposed to $0.05\%$ CaO solution for 10 min. Moreover, the bactericidal action of CaO was maintained for at least 24 h of storage. The results of this study provide evidence that CaO, as a substitute for synthetic chemical substances has potential for use in the disinfection and sanitization of foods and food processing equipment.

• The Korean Journal of Ecology
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• 제12권2호
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• pp.109-122
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• 1989

The vegetation and landscape of Hokkaido were phytosociologically referred. The region of F a g e t e a c r e n a t a e on Hokkaido is divided into two types of deciduous broad-leaved forest: the oak (Quercus mongolica var. grosseserrata) forests mixed with conifers (mainly Abies sachalinensis) and the beech (Fagus crenata) forests of northernmost distribution in far-east Asia. The oak forests, which is dominated by Quercus mongolica var. grosseserrata in Japanse islands, seem to be developed from different climatic and edaphic conditions, especially in the amount and sharing pattern of precipitation in a year, and weak acid brown forest soil, volcanic ash soil and sandy soil. On the all-inclusive phytogeographical view-point, Hokkaido is situated at northernmost region of F a g e t e a c r e n a t a e (cool-temperate zone)neighboring with subarctic and subalpine vegetation, vegetation, but the evergreen broad-leaved forest (C a m e l l i e t e a j a p o n i c a e, warm-temperate zone) is abscent.

• 한국식품영양과학회지
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• 제39권10호
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• pp.1411-1417
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• 2010

총 폴리페놀 함량은 로즈마리에서 가장 높은 폴리페놀 함량을 보였고, 구절초, 라벤더, 레몬그라스도 $72{\sim}80\;{\mu}g$/mg의 비교적 높은 폴리페놀 함량을 보였다. 반면 카렌듈라와 목향은 다른 허브류보다 20~40% 정도의 낮은 폴리페놀의 함량을 보였다. 그리고 총 플라보노이드 함량에서는 레몬그라스, 로즈마리, 구절초, 카렌듈라, 라벤더, 목향 순으로 높은 함량을 나타냈다. 로즈마리, 라벤더, 구절초, 레몬그라스는 최고농도에서 90% 이상의 높은 DPPH 소거능이 있었고, $IC_{50}$값은 로즈마리 $6.23{\pm}0.58\;{\mu}g/mL$, 라벤더 $18.29{\pm}0.68\;{\mu}g/mL$, 구절초 $20.33{\pm}1.04\;{\mu}g/mL$, 레몬그라스 $22.38{\pm}0.77\;{\mu}g/mL$, 카렌듈라 $60.03{\pm}4.01\;{\mu}g/mL$, 목향 $65.64{\pm}2.64\;{\mu}g/mL$이었다. 이들 허브 추출물들의 항균 활성을 살펴보면, S. aureus 균주는 최고농도 100 mg/mL에서 구절초 14.5 mm, 로즈마리 15 mm로 가장 뛰어난 항균활성을 나타내었고, E. coli O157:H7 균주는 최고농도 100 mg/mL에서 구절초 16 mm, 로즈마리 17 mm로 우수한 항균효과를 나타냈다. 따라서 허브류 중에서 로즈마리 추출물이 가장 높은 총 폴리페놀의 함량을 보였고, 총 플라보노이드의 함량은 레몬그라스에서 가장 높았다. 또한 S. aureus와 E. coli O157:H7 2종류의 균에 대한 항균 효과는 로즈마리와 구절초에서 가장 뛰어난 효과를 확인하였다.

• 농약과학회지
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• 제5권1호
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• pp.12-18
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• 2001

유기인계 농약에 대한 cholinesterase(ChE)활성저해 관계를 규명 하고자 in vivo와 in vitro 실험을 하였다. 병아리 혈장의 ChE 활성은 $23{\mu}mol$/min/g protein이었다. in vivo에서 terbufos의 투여량을 $LD_{50}$의 0.2배(0.362 mg/kg)와 0.5배(0.905 mg/kg)로 투여하였을 경우, 투여 15분 후에 ChE 활성이 각각 36%와 96%까지 저해되었으며 그 후 회복이 일어난다. in vitro에서 유기인계의 P에 S가 결합된 P=S구조의 phosphorodithioate와 phosphorothioate의 Ki는 $74{\sim}322\;mole^{-1}min^{-1}$로 낮았다. 그러나 P에 S가 산화되어 O가 결합된 P=O구조의 phosphate와 phosphorothiolate의 Ki는 $13898{\sim}79610\;mole^{-1}min^{-1}$로 높았다. 따라서 P=S가 P=O로 산화됨으로서 ChE의 저해도가 커져서 독성이 강해짐을 확인하였다. phosphorodithioate와 phosphorothioate형의 $pI_{50}$값은 $21{\sim}102 mg/L(ppm)$ 이었다. 그러나 phosphate와 phosphorothiolate형의 $pI_{50}$값은 $0.519{\sim}0.071$ mg/L(ppm)이었다. 즉 ChE을 이용한 enzyme-inhibition(EI)법을 유기인계 농약의 정성적 검출에 이용한다면, P=O구조인 phosphate와 phosphorothiolate형은 1ppm이하 즉 ppb단위까지 정성적 검출이 가능하다.

• 대한화장품학회지
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• 제38권1호
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• pp.57-65
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• 2012

본 연구에서는 비파엽 추출물의 항산화 활성, 타이로시네이즈 저해 활성, 및 추출물/분획의 성분 분석에 대한 연구를 수행하였다. 비파엽 추출물의 자유라디칼(1,1-diphenyl-2-picrylhydrazyl, DPPH) 소거활성($FSC_{50}$)은 50 % 에탄올 추출물($22.63{\mu}g/mL$) < 에틸아세테이트(ethyl acetate) 분획(6.75) < 당을 제거시킨 아글리콘(aglycone) 분획(5.06) 순으로 증가하였다. 루미놀(luminol)-의존성 화학발광법을 이용한 $Fe^{3+}-EDTA/H_2O_2$ 계에서 생성된 활성산소종(reactive oxygen species, ROS)에 대한 총항산화능은 에틸아세테이트 분획($OSC_{50}$, $0.75{\mu}g/mL$), 아글리콘 분획(0.79) 및 50 % 에탄올 추출물(1.61)에서 모두 큰 활성을 나타내었다. 비파엽 추출물의 rose-bengal로 증감된 사람 적혈구의 광용혈에 대한 보호효과를 조사하였다. 비파엽 추출물은 모든 분획에서 농도 의존적($5{\sim}50{\mu}g/mL$)으로 증가하였으며, 특히 에틸아세테이트 분획은 $10{\mu}g/mL$ 농도에서 ${\tau}50$이 390.8 min, $50{\mu}g/mL$ 농도에서 ${\tau}50$이 1471.5 min으로 높은 세포 보호 활성을 나타내었다. 타이로시네이즈 저해 활성($IC_50$)은 에틸아세테이트 분획($75.25{\mu}g/mL$) < 50 % 에탄올 추출물($74.1{\mu}g/mL$) < 아글리콘 분획($43.35{\mu}g/mL$) 순으로 미백제로 알려진 알부틴보타 타이로시네이즈 저해활성이 크게 나타났다. 비파엽 추출물 중 에틸아세테이트 분획의 TLC 분석 결과 7개의 띠(EJL 1 - EJL 7)가 나타났다. HPLC로 아글리콘 분획을 분석한 결과 kaempferol 및 quercetin이 각각 53.7 % 및 46.3 %였으며, 따라서 추출물 중에는 kaempferol 및 그 배당체 비율이 다소 높은 것으로 나타났다. 이상의 결과들은 비파엽 추출물 또는 분획이 $^1O_2$ 및 다른 ROS를 소거 또는 소광함으로써 그리고 ROS에 대항해서 세포막을 효과적으로 보호함으로써 태양 자외선에 노출된 피부를 보호하는 항산화제로서 작용할 수 있음을 가리키며, 타이로시네이즈 저해 효과로부터 비파엽 추출물 및 분획물은 기능성 화장품 원료로서 응용가능성이 있음을 시사한다.

• Bulletin of the Korean Chemical Society
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• 제18권9호
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• pp.916-922
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• 1997

A superconducting phase La2CuO4+δ (Tc=44 K) has been prepared by electrochemical oxidation which allows the oxygen to intercalat into the La2O2 layers. According to the Cu K-edge X-ray absorption near edge structure spectroscopic analysis, the oxidized phase shows an overall spectra shift of about 0.5 eV to a higher energy region compared to the as sintered one with the occurrence of an additional peak corresponding to the transition to the |1s13dn+1L-14pσ1 > final state, indicating the oxidation of CuO2 layer. From the X-ray photoelectron spectroscopic studies, it is found that the binding energy of La 3d5/2 is significantly shifted from 834.3 eV (as sintered La2CuO4) to 833.6 eV (as electrochemically oxidized La2CuO4+δ), implying that the covalency of the (La-O) bond is decreased due to the oxygen intercalation. The O 1s spectra do not provide an evidence of the superoxide or peroxide, but the oxide (O2-) with the contaminated carbonate (CO32-) based on the peaks at 529 eV and 532 eV, respectively, which is clearly confirmed by the Auger spectroscopic analysis. Oxygen contents determined by iodometric titration (δ=0.07) and thermogravimetry (δ=0.09) show good coincidence each other, also giving an evidence for the "O2-" nature of excess oxygen. From the above results, it is concluded that "O2-" appeared as O 1s peak at 528.6 eV is responsible for superconductivity of La2CuO4+δ.

• Fisheries and Aquatic Sciences
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• 제15권1호
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• pp.15-19
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• 2012

A new cyclic peptide (six-membered amino acid), gamakamide-E (L-Leu-L-Met (SO)-L-Me-Phe-L-Leu-D-Lys-L-Phe), was isolated as a strongly bitter tasting compound from cultured oysters, Crassostrea gigas. The molecular formula of $C_{43}H_{61}N_7O_8S$ was deduced from high resolution fast atom bombardment mass spectrometry (HR FAB-MS) ($[M+H]^+$ m/z 836.4356 ${\Delta}$= -2.4 mmu). Its unique structure including a hydantoin structure was firstly elucidated by nuclear magnetic resonance (NMR) analysis. Stereochemistries of constituent amino acids were determined by chiral high performanced liquid chromatography analysis of natural and synthesized peptides.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 B
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• pp.546-549
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• 1993

The correlation between electrical conduct ion and dielectric relaxation properties of copper ion conducting glasses is discussed. The glasses were prepared in the system $CuI-Cu_2S-Cu_2O-MoO_3$ using rapid quenching technique. These glasses have high ionic conductivities at room temperature in the range of $10^{circ}$[S/m], and the conductivities increase with increasing CuI content. The activation energies for conduction are 0.26-0.57 eV. The dielectric relaxation times are 1-10uS, and the activation energy for ion jumping are 0.18-0.41eV. It is shown that the tendency of conduction properties depending on composition of the glass is similar those of dilectric relaxation.

• Journal of Ecology and Environment
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• 제33권4호
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• pp.289-298
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• 2010

A number of characteristics of the Lake H$\ddot{o}$vsg$\ddot{o}$l watershed, such as the lake's location at the edge of the Central Asian continuous permafrost zone, provide a unique opportunity to evaluate possible anthropogenic impacts in this remote area in northern Mongolia. In this study, we compared stream solute concentrations in six sub-watersheds in the Lake H$\ddot{o}$vsg$\ddot{o}$l watershed. Water samples were collected during the summer months between 2003 and 2005. Concentrations of $Cl^-$ ranged from 9.8 to $51.3\;{\mu}mol/L$; average nitrate concentrations were very low and ranged from undetectable to $1.1\;{\mu}mol/L$ and average ${SO_4}^{2-}$ concentration at sampling stations with minimal animal grazing ranged from 66 to $294\;{\mu}mol/L$. Average dissolved organic carbon (DOC) concentrations ranged from 642 to $1,180\;{\mu}mol$ C/L. We did not find statistically significant differences in DOC concentrations among the six streams, although DOC concentrations tended to be higher in the two northernmost streams, possibly related to differences in the active layer above the permafrost. Dissolved organic nitrogen (DON) concentrations were correlated with DOC concentration, and followed the same spatial pattern as those for DOC. In streams in this remote watershed, total dissolved nitrogen was made up of mostly organic N, as has been found for other regions distant from anthropogenic N sources. Overall, these results suggest that future research on the dynamics of DOC and DON in this watershed will be especially insightful in helping to understand how changes in climate and land use patterns will affect transformations, retention, and export of dissolved organic matter within these sub-watersheds in the Lake H$\ddot{o}$vsg$\ddot{o}$l region.