• Applied Biological Chemistry
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• 제51권3호
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• pp.223-227
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• 2008

사자발쑥의 지상부를 80% MeOH용액으로 추출하고, 얻어진 추출물을 EtOAc, H-BuOH 및 $H_2O$로 용매 분획 하였다. 이 중 EtOAc 분획으로부터 silica gel과 octadecyl silica gel(ODS), Sephadex LH-20 column chromatography로 정제하여 4종의 triterpenoid를 분리하였다. 각 화합물의 화학구조는 NMR, MS 및 IR 등의 스펙트럼 데이터를 해석하여 wrightial(1), wrightial acetate(2), 27-norcycloart-20(21)-ene-25-al-3${\beta}$-ol acetate(3) 및 ursolic acid(4)로 동정하였다. 이 화합물들은 사자발쑥에서 처음으로 분리 보고 되었으며 특히, 화합물 3은 천연에서 처음으로 분리 보고 되었다. 또한 이번에 분리한 화합물에 대하여 항고지혈증 활성을 측정한 결과 화합물 1은 ACAT1과 ACAT2 효소에 대한 $IC_{50}$ 값이 33 ${\mu}g/ml$와 45 ${\mu}g/ml$로 나타났고, 화합물 2는 ACAT1 효소에 대하여 $IC_{50}$ 값이 12 ${\mu}g/ml$로 나타났다. 화합물 3은 ACATI 효소에 대하여 $IC_{50}$값이 16 ${\mu}g/ml$으로 나타났다.

• 한국식품과학회지
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• 제33권6호
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• pp.753-759
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• 2001

Aloe vera 껍질로부터 구내염등 항염증제재를 개발하기 위해 항염증 활성이 있는 분획을 분리, 동정하고, 염증과 관련된 효소활성에 대한 저해효과를 조사하였다. Aloe vera 껍질의 추출물을 용매에 따라 분획하였고, 활성이 우수한 ethylacetate층을 silica gel column chromatography 및 preparative thin layer chromatography를 통해 두 가지 활성물질을 정제하였다. 정제된 두 가지 물질은 UV spectrum과 FT-IR, $^1H-NMR$, 및 Mass spectrum 분석을 통해 aloe-emodin과 barbaloin으로 동정하였다. Aloe vera 분획물의 hyaluronidase 활성저해를 측정한 결과는 aloe-emodin은 $40\;{\mu}g/mL$, barbaloin은 $70\;{\mu}g/mL$의 $IC_{50}$값을 나타내었다. Leucko-cyte elastase 활성 저해를 측정한 결과는 aloe-emodin은 $50\;{\mu}g/mL$, barbaolin은 $60\;{\mu}g/mL$의 $IC_{50}$값을 나타내었다. Collagenase 활성 저해를 측정한 결과는 aloe-emodin은 $40\;{\mu}g/mL$, barbaloin은 $60\;{\mu}g/mL$의 $IC_{50}$값을 나타내었다. 또한 prostaglandin endoperoxide synthase 활성 저해를 측정한 결과는 aloe-emodin은 $40\;{\mu}g/mL$, barbaloin은 $70\;{\mu}g/mL$의 $IC_{50}$값을 나타내었다. 쥐를 이용한 carrageenan족 부종 억제효과는 aloe-emodin의 경우 100mg/kg 투여량으로 52.9%의 억제효과를 나타내었으며, 이 억제효과는 indomethacin의 약 1/10이었으며, aspirin과는 유사한 활성을 보였다. 반면 barbaloin의 경우 100mg/kg의 투여량으로 74.9%의 억제효과를 나타내었으며 이 억제효과는 indomethacin의 약 1/5이었으며, aspirin의 약 1.5배 효과를 나타내어 우수한 항염증 활성을 갖는 것으로 판단된다. 인체치은세포에 대한 독성은 aloe-emodin보다 barbaloin이 적게 나타났으며 이 두 가지 물질은 1 및 $5\;{\mu}g/mL$농도에서는 독성이 전혀 나타나지 않으나 10 및 $20\;{\mu}g/mL$에서는 독성이 있는 것으로 나타났다. 그러나 상용되고 있는chlorhexidin에 비해서는 유의적으로 독성이 적은 것으로 나타났다. 이상의 결과로 보아 aloe-emodin 과 barbaloin은 항우식 및 항염증 활성이 우수할 뿐만 아니라 치은세포의 독성이 비교적 낮아 구강병 예방제재로의 개발 가능성이 우수하다고 사료된다.

• 농업생명과학연구
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• 제45권4호
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• pp.1-11
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• 2011

본 연구는 국내산 침엽수로부터 천연 항균화합물 개발을 목표로 미송 및 편백으로부터 추출물을 확보하여 푸른곰팡이병의 원인균인 Trichoderma spp. 5종을 대상으로 항균활성을 테스트하고 GC/MS를 이용하여 항균화합물을 탐색하였다. 미송 추출물은 Trichoderma spp.에 대해 1,000 ppm에서 저해 활성을 나타냈으며, 4,000 pp에서는 T. viride>T. harzianum>T. aggressivum 순으로 70.1, 67.3, 64.7%의 높은 항균활성을 나타냈다. 편백 추출물도 1,000 ppm에서 항균활성을 나타냈고 4,000 ppm에서 T. viride>T. harzianum>T. aggressivum 순으로 63.2, 59.3, 59.1%의 높은 항균활성을 나타냈다. 그러나 1,000 ppm의 미송추출물과 1,000 ppm의 편백추출물을 각각 9:1, 8:2, 6:4, 2:8 (w/w) 비율의 혼합제제로 만들어 Trichoderma spp.에 처리하였을 때 미송추출물 1,000 ppm 및 편백추출물 1,000 ppm 각각의 단일추출물보다 낮은 항균활성을 나타냈다. Trichoderma spp. 5종에 대해 높은 항균활성을 나타내는 미송추출물에서는 2-Isopropoxy-ethylamine 46.5%, epifluorohydrin 8.6%, trans-2,3-Di-methyloxirane 7.6%, (IR)-(-)-Myrtenal 6.0%, 2-Methoxy-4-Vinylphenol 3.9%, benzaldehyde 2.8%가 함유되어 있었고, 편백추출물에서는 ${\alpha}$-Terpinenyl acetate 14.9%, Sabinene 10.9%, dl-Limonene 9.6%, ${\alpha}$-Terpinolene 7.5%, ${\alpha}$-Pinene 7.1%가 함유된 것이 확인되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.254-255
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• 2012

Interest in nano-crystalline silicon (nc-Si) thin films has been growing because of their favorable processing conditions for certain electronic devices. In particular, there has been an increase in the use of nc-Si thin films in photovoltaics for large solar cell panels and in thin film transistors for large flat panel displays. One of the most important material properties for these device applications is the macroscopic charge-carrier mobility. Hydrogenated amorphous silicon (a-Si:H) or nc-Si is a basic material in thin film transistors (TFTs). However, a-Si:H based devices have low carrier mobility and bias instability due to their metastable properties. The large number of trap sites and incomplete hydrogen passivation of a-Si:H film produce limited carrier transport. The basic electrical properties, including the carrier mobility and stability, of nc-Si TFTs might be superior to those of a-Si:H thin film. However, typical nc-Si thin films tend to have mobilities similar to a-Si films, although changes in the processing conditions can enhance the mobility. In polycrystalline silicon (poly-Si) thin films, the performance of the devices is strongly influenced by the boundaries between neighboring crystalline grains. These grain boundaries limit the conductance of macroscopic regions comprised of multiple grains. In much of the work on poly-Si thin films, it was shown that the performance of TFTs was largely determined by the number and location of the grain boundaries within the channel. Hence, efforts were made to reduce the total number of grain boundaries by increasing the average grain size. However, even a small number of grain boundaries can significantly reduce the macroscopic charge carrier mobility. The nano-crystalline or polymorphous-Si development for TFT and solar cells have been employed to compensate for disadvantage inherent to a-Si and micro-crystalline silicon (${\mu}$-Si). Recently, a novel process for deposition of nano-crystralline silicon (nc-Si) thin films at room temperature was developed using neutral beam assisted chemical vapor deposition (NBaCVD) with a neutral particle beam (NPB) source, which controls the energy of incident neutral particles in the range of 1~300 eV in order to enhance the atomic activation and crystalline of thin films at room temperature. In previous our experiments, we verified favorable properties of nc-Si thin films for certain electronic devices. During the formation of the nc-Si thin films by the NBaCVD with various process conditions, NPB energy directly controlled by the reflector bias and effectively increased crystal fraction (~80%) by uniformly distributed nc grains with 3~10 nm size. The more resent work on nc-Si thin film transistors (TFT) was done. We identified the performance of nc-Si TFT active channeal layers. The dependence of the performance of nc-Si TFT on the primary process parameters is explored. Raman, FT-IR and transmission electron microscope (TEM) were used to study the microstructures and the crystalline volume fraction of nc-Si films. The electric properties were investigated on Cr/SiO2/nc-Si metal-oxide-semiconductor (MOS) capacitors.

• 천문학논총
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• 제32권1호
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• pp.201-203
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• 2017

There exists strong evidence supporting the co-evolution of central supermassive black holes and their host galaxies; however it is still under debate how such a relation comes about and whether it is relevant for all or only a subset of galaxies. An important mechanism connecting AGN to their host galaxies is AGN feedback, potentially heating up or even expelling gas from galaxies. AGN feedback may hence be responsible for the eventual quenching of star formation and halting of galaxy growth. A rich multi-wavelength dataset ranging from the X-ray regime (Chandra), to far-IR (Herschel), and radio (WSRT) is available for the North Ecliptic Pole field, most notably surveyed by the AKARI infrared space telescope, covering a total area on the sky of 5.4 sq. degrees. We investigate the star formation properties and possible signatures of radio feedback mechanisms in the host galaxies of 237 radio sources below redshift z = 2 and at a radio 1.4 GHz flux density limit of 0.1 mJy. Using broadband SED modelling, the nuclear and host galaxy components of these sources are studied simultaneously as a function of their radio luminosity. Here we present results concerning the AGN content of the radio sources in this field, while also offering evidence showcasing a link between AGN activity and host galaxy star formation. In particular, we show results supporting a maintenance type of feedback from powerful radio-jets.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.40-44
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• 2003

Soil-borne infectious disease including Pythium aphanidermatum and Rhizoctonia solani causes severe damage to plants, such as cucumber. This soil-borne infectious disease was not controlled effectively by chemical pesticide. Since these diseases spread through the soil, chemical agents are usually ineffective. Instead, biological control, including antagonistic microbe can be used as a preferred control method. An efficient method was developed to select an antagonistic strain to be used as a biological control agent strain. In this new method, surface tension reduction potential of an isolate was included in the ‘decision factor’ in addition to the other factors, such as growth rate, and pathogen inhibition rate. Considering these 3 decision factors by a statistical method, an isolate from soil was selected and was identified as Bacillus sp. GB16. In the pot test, this strain showed the best performance among the isolated strains. The lowest disease incidence rate and fastest seed growth was observed when Bacillus sp. GB16 was used. Therefore this strain was considered as plant growth promoting rhizobacteria (PGPR). The action of surface tension reducing component was deduced as the enhancement of wetting, spreading, and residing of antagonistic strain in the rhizosphere. This result showed that new selection method was significantly effective in selecting the best antagonistic strain for biological control of soil-borne infectious plant pathogen. The antifungal substances against P. aphanidermatum and R. solani were partially purified from the culture filtrates of Bacillus sp. GB16. In this study, lipopeptide possessing antifungal activity was isolated from Bacillus sp. GB16 cultures by various purification procedures and was identified as a surfactin-like lipopeptide based on the Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), high performance liquid chromatography mass spectroscopy (HPLC-MS), and quadrupole time-of-flight (Q-TOF) ESI-MS/MS data. The lipopeptide, named GB16-BS, completely inhibited the growth of Pythium aphanidermatum, Rhizoctonia solani, Penicillium sp., and Botrytis cineria at concentrations of 10 and 50 mg/L, respectively. A novel method to prevent the foaming and to provide oxygen was developed. During the production of surface active agent, such as lipopeptide (surfactin), large amount of foam was produced by aeration. This resulted in the carryover of cells to the outside of the fermentor, which leads to the significant loss of cells. Instead of using cell-toxic antifoaming agents, low amount of hydrogen peroxide was added. Catalase produced by cells converted hydrogen peroxide into oxygen and water. Also addition of corn oil as an oxygen vector as well as antifoaming agent was attempted. In addition, Ca-stearate, a metal soap, was added to enhance the antifoam activity of com oil. These methods could prevent the foaming significantly and maintained high dissolved oxygen in spite of lower aeration and agitation. Using these methods, high cell density, could be achieved with increased lipopeptide productivity. In conclusion to produce an effective biological control agent for soil-borne infectious disease, following strategies were attempted i) effective screening of antagonist by including surface tension as an important decision factor ii) identification of antifungal compound produced from the isolated strain iii) novel oxygenation by $H_2O_2-catalase$ with vegetable oil for antifungal lipopeptide production.

• 한국식품영양과학회지
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• 제36권11호
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• pp.1385-1390
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• 2007

당귀로부터 항암활성을 화합물을 silicagel column chromatography를 이용하여 분리 및 정제한 후, $^1H$와 $^{13}C-NMR$ MS, HMQC 및 COSY spectrum(500 MHz $CDCl_3$) 분석을 통하여 분자량 328의 decursin임을 구조 동정하였다. 정제된 decursin을 MCF-7에 24시간 처리한 결과 $20{\mu}g/mL$ 이상에서 농도 의존적으로 암세포주의 성장을 억제하였으며, SW480, HepG2, MCF-7및 293과 같은 인체 암세포주에 대한 decurcin의 $IC_{50}$값은 각각 31.04, 27.24, 20.45 및 $33.60{\mu}g/mL$로 나타나, decursin은 인체 정상세포주인 293세포를 포함한 다른 세포에 비하여 MCF-7에 대하여 가장 높은 성장억제 활성을 보여주었다. MCF-7세포에 decursin을 처리한 결과 대조군에서 균일한 핵의 형태가 관찰된 것에 반해 처리군의 경우는 핵의 응축과 apoptotic body를 보였고, DNA 절편이 관찰되었다. 이 결과는 당귀에서 분리한 decursin은 MCF-7세포에서 apoptosis를 통하여 세포의 성장을 억제하는 것을 암시한다.

• 공업화학
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• 제10권1호
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• pp.124-128
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• 1999

개별적인 반응성이 알려진 니트로기와 벤질술포닐기가 벤젠 고리 위에서 서로 인접하여 위치할 때 광반응성에 미치는 상호 작용에 대해서 연구하고자 하였다. 니트로기를 포함하는 술포닐 에스테르(cyclohexyl 및 phenyl 2-nitro-${\alpha}$-toluenesulfonate)와 슬포닐아미드(시클로헥실, 페닐, 벤질, 및 피페리딜 2-nitro-${\alpha}$-toluenesulfonamide)의 용액 중 광반응 생성물로부터 벤질술포닐기와 그 ortho 위치에 존재하는 니트로기가 광반응시 서로 상승작용을 하지 않는다는 것을 알 수 있었다. 용액상의 광반응은 이어 필름 상에서의 광반응으로 확인 및 응용되었다. 즉, 두 가지의 2-nitro-${\alpha}$-toluensulfonamide를 포함한 poly(methacrylonitrile)(PMAN) 박막을 NaCl 판 위에 입히고 여기에 254 nm 자외선을 쪼이면서 관찰된 필름의 IR 스펙트럼의 변화로부터도 용액상의 광반응을 일부 확인하였으며 정량실험도 실시하였다. 또한, 본 용액실험의 결과인 광화학적 아민 발생은 poly(glycidyl methacrylate)를 이용한 상 발생 실험에 응용되어 성공적으로 광화학적 에폭시 가교를 수행할 수 있었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권2호
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• pp.54-61
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• 2012

In this study, the adsorption of $Cu^{2+}$ from aqueous solution by the biochar derived from woody biomass at different pyrolysis temperatures has been investigated. The woody biomass wastes used in this study were branch of willow ($Salix$ $koreensis$ $Andersson$) and bark of chestnut ($Castanea$ $crenata$ $var.$ $dulcis$). Three biochar samples prepared by heating each biomass at temperature of $300^{\circ}C$, $500^{\circ}C$, and $700^{\circ}C$were tested for the adsorption capacity of Cu. Also the physicochemical properties of the developed biochars were studied using different characterization techniques such as FT-IR, SEM, BET surface area, and cation exchange capacity (CEC). The adsorption of Cu could be well described by Langmuir model for both willow and chestnut biochars with $R^2{\geq}0.98$. The maximum adsorption capacities of the biochar produced at $700^{\circ}C$ from the Langmuir equation were found to be 12.5 mg $g^{-1}$ and 16.9 mg $g^{-1}$ for willow and chestnut, respectively. Chestnut biochar was found to interact more effectively with the active sites available for Cu, resulting higher removal of Cu(II) than wiloow biochar. Ion exchange and surface complexation found to be the main mechanisms involved in the adsorption process. This study demonstrated the feasibility of the biochars derived from woody biomass to be as a low-cost potential adsorbent for heavy metals as Cu(II) removal in aquatic system.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1527-1527
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• 2001

Glucose, fructose and sucrose being the main sugars that can be found in natural fruit juice. Many instrumental methods, such as GC, LC, electrochemical or spectrometric methods provide information about both the total content of sugars and the specific concentration of each carbohydrate[1]. The simplicity of sample handling and measurement in the near IR(NIR) wavelength region, which allows the use of long pathlength, optical glass cells and optical fibers, makes NIR a good alternative for sugar determination [2]. In the present study, six varieties of persian grapes were harvested at intervals through august to october and analysed for sugars by NIR. The results were processed by principal component regression (PCR) and partial least squares (PLS) analysis. Sample juice was prepared by squeezing through gauze from crashed grape. This solution was treated by zinc ferrocyanide prior to analysis in order to eliminate colored compounds and all optically active nonsugar substances. For glucose and fructose the most characteristic wavelengths were 1456nm corresponding to the first harmonic O-H stretching and the second at 2062nm corresponding to O-H stretching and deformation; secondary characteristic combination bands were also seen at 2265 nm (O-H and C-C stretching) and at 2240 nm (C-H and C-C stretching). However these spectra were taken over a wavelength range from 1100-2500nm at room temperature of 25-$30^{\circ}C$. To test the accuracy of the described procedure, samples of six varieties of grape were analysed by the proposed NIR and a standard method[2]. Good agreement were found between these two sets of the results. To perform the recovery studies , samples of grape juices previously analysed by the proposed method, were spiked with known amounts of each individual sugars and then analysed again. Relative standard deviations varied from 1.4 to 1.8% for six independent measurements of individual and total sugar concentration. In the analysis of real and synthetic samples, precise and accurate results were obtained , providing accuracy errors lower than 1.9% in all cases. Average recoveries of ${97}{\pm}{4%}$ for total sugar and between ${95}{\pm}{5%}$ and ${99}{\pm}{2%}$ for sing1e sugars demonstrate the applicability of the methodology developed to the direct analysis of grape Juice.