• 한국식품과학회지
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• 제29권2호
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• pp.302-308
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• 1997

Epichlorohydrin을 이용하여 ${\beta}-CD$ 중합체를 제조한 후 차단분자량 10,000인 막(YM 10)을 이용하여 수용성 ${\beta}-CD$ 중합체와 불용성 ${\beta}-CD$ 중합체를 분리하였다. 최적분리 조건은 막횡단압력 51.7 kPa, 운용온도 $35^{\circ}C$, 용적농축비 10이었으며, 이때의 flux는 $0.025\;mL/cm^{2}/min$ 이었다. 겔 투과 크로마토그래피 결과 수용성 중합체의 중합도는 $2{\sim}8$, 불용성 중합체는 10 이상으로 나타났으며, 이들 ${\beta}-CD$ 중합체의 소수성 물질들과의 포접 형성능을 비교하였다. 색소물질인 4-dimethylaminoazobenzene과 methyl red를 이용하여 ${\beta}-CD$와 ${\beta}-CD$ 중합체와의 포접 능력을 측정하였다. 포접 복합체 형성 여부를 간접적으로 알 수 있는 분광학적 변화를 측정한 결과 두 색소물질 흡광도의 강도가 증가하였으며 최대 흡광도 위치가 변하였다. 감귤류의 주된 flavonoid이며 쓴맛물질인 naringin은 물에 대한 용해도가 낮으나 ${\beta}-CD$ 중합체과 포접복합체를 형성함으로써 수용성이 증가하였다. ${\beta}-CD$ 단위체보다는 ${\beta}-CD$ 중합체의 포접능력이 훨씬 강하였으며, 중합도별 포접능력에 있어 불용성 ${\beta}-CD$ 중합체와 수용성 ${\beta}-CD$ 중합체간에 큰 차이는 나타나지 않았다. ${\beta}-CD$ 단위체는 용해도가 극히 낮아 쓴맛 물질 제거 이용에 있어 제한이 있는 반면, 수용성 ${\beta}-CD$ 중합체는 용해도가 높아 감귤류 등으로부터 쓴맛 성분을 감소시키는 공정에의 이용 가능성이 높은 것으로 나타났다.

• 농약과학회지
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• 제18권4호
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• pp.376-382
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• 2014

황토유황합제 제조 5주 후 녹지 않은 잔재물을 제외하고 수용성 황토유황합제만 준비하였다. 황토유황합제 제조시 가성소당를 원래 양보다 25% 감량하여 황토유황합제의 pH를 pH 1 낮추었다. 현미식초(pH 2.8)을 이용하여 황토유황합제의 pH 수준을 pH 5.0에서11.0까지 현미식초(pH 2.8)를 이용하여 pH를 1씩 조절하였다. 황토유황합제 원액의 pH는 13으로 토마토에 살포하였을 때 신초와 꽃눈에 약해를 주었다. pH가 조정된 0.05% 황토유황합제를 E. cichoracearum에 의해 흰가루병이 발생한 토마토에 7일간격으로 2회 살포하였다. pH가 조정된 황토유황합제를 1회 살포하고 7일 후 토마토의 흰가루병이 70~95% 방제되었다. 두 번째 살포 후 토마토 흰가루병이 확연하게 방제되었다. 결론적으로 pH를 조정한 황토유황합제는 토마토에 약해를 보이지 않으며, 유기농업에서 토마토 흰가루병 방제용 자재로 사용할 수 있을 것으로 생각한다.

• Journal of Microbiology
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• 제41권3호
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• pp.212-218
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• 2003

Citrus phytoene synthase (CitPsy) and ${\beta}$-carotene hydroxylase (CitChx), which are involved in caroteinoid biosynthesis, are distantly related to the corresponding bacterial enzymes from the point of view of amino acid sequence similarity. We investigated these enzyme activities using Pantoea ananatis carotenoid biosynthetic genes and Escherichia coli as a host cell. The genes were cloned into two vector systems controlled by the T7 promoter. SDS-polyacrylamide gel electrophoresis showed that CitPsy and CitChx proteins are normally expressed in E. coli in both soluble and insoluble forms. In vivo complementation using the Pantoea ananatis enzymes and HPLC analysis showed that ${\beta}$-carotene and zeaxanthin were produced in recombinant E. coli, which indicated that the citrus enzymes were functionally expressed in E. coli and assembled into a functional multi-enzyme complex with Pantoea ananatis enzymes. These observed activities well matched the results of other researchers on tomato phytoene synthase and Arabidopsis and pepper ${\beta}$-carotene hydroxylases. Thus, our results suggest that plant carotenoid biosynthetic enzymes can generally complement the bacterial enzymes and could be a means of carotenoid production by molecular breeding and fermentation in bacterial and plant systems.

• 자원환경지질
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• 제17권4호
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• pp.289-298
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• 1984

Uraniferous black slates of the Okchon sequence occur in Koesan (northeast) through Miwon-Boun (middle) to the southwest off Taejon (southwest) within the Okchon fold belt. The Uraniferous balck slates in the southwest off Taejon are particularly well developed in Chubu (northeast) and Moksso-ri (middle) areas whereas they are less developed in Jinsan (southwest) area. The uraniferous beds range from less than a meter to 40 meters in thickness and range from less than 0.02% $U_3O_8$ (cut-off-grade) to 0.05% $U_3O_8$ in the southwestern district off Taejon. Electron microprobe analysis of uranium-minerals found in graphitic slate samples enables to estimate their major compositions semi-quantitatively so that uraninite, ferro-uranophane and chlopinite are tentatively identified. Uranium-minerals are closely associated with carbon and metal sulfides. Correlation analysis of trace element concentrations revealed that U and F.C., and U and Mo are lineary correlative respectively and their correlation coefficients are positively high whereas those of U and V, U and Mn, and U and Zr are negatively low, implying that uranium mineralization has been closely related with concentrations of carbon and molybdenum. Stable isotope analyses of pyrite sulfur range widely from +11.5% to -23.3% in ${\delta}^{34}S$ values whereas those of graphite carbon fall within a narrow range between -23.3% and -28.9% in ${\delta}^{13}C$ values. The wide range of ${\delta}^{34}S$ values suggests that the sulfur could be of meteoric origin rather than of igneous source. The narrow range of ${\delta}^{13}C$ values, which are close to those of coal, indicates that the graphite is organic carbon in origin. Therefore, it is concluded that the uranium mineralization in the Okchon sequence took place primarily in sedimentary environment rich in organic matter and sulfide ion, both of which served as the reducing agents to convert soluble uranyl complex to insoluble uranium dioxide.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.855-858
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• 2005

The bioavailability of Ca is currently one of the most important topics in nutrition research and is correlated with gastrointestinal solubility. Thus, to increase the solubility of calcium, this study was undertaken to examine the effect of $\gamma$-PGA on intestinal Ca solubility. The calcium solubility increased when the amount of $\gamma$-PGA was increased, due to the inhibition of the formation of an insoluble Ca complex with phosphate. Therefore, when $\gamma$-PGA-500 (avg. MW 5,000 kDa) was added at 0.5 mg/ml, $75\%$ of the total Ca was soluble. The amount of soluble Ca uptake in the small intestine was investigated using Balb/c mice as an animal model system. The soluble Ca uptake in the mice orally administered with $\gamma$-PGA-500 (avg. MW 5,000 kDa) was significantly higher than that in the $\gamma$-PGA-l00 (avg. MW 1,000 kDa)-administered mice (P<0.05). Accordingly, these results strongly support the notion that the molecular size of $\gamma$-PGA is correlated with Ca solubility. The effects of other factors, such as casein phosphopeptide and vitamin D, on intestinal Ca absorption have also previously been investigated. Therefore, it is hoped that the present observations will help clarify the role of $\gamma$-PGA in Ca solubility and its industrial application as an additive.

• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.199-206
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• 2012

Naturally immobilized tannase (tannin acyl hydrolase, E.C. 3.1.1.20) has many advantages, as it avoids the expensive and laborious operation of isolation, purification, and immobilization, plus it is highly stable in adverse pH and temperature. However, in the case of cell-associated enzymes, since the enzyme is associated with the biomass, separation of the pure biomass is necessary. However, tannic acid, a known inducer of tannase, forms insoluble complexes with media proteins, making it difficult to separate pure biomass. Therefore, this study optimizes the production of cell-associated tannase using a "protein-tannin complex" free media. An exploratory study was first conducted in shake-flasks to select the inducer, carbon source, and nitrogen sources. As a result it was found that gallic acid induces tannase synthesis, a tryptose broth gives higher biomass, and lactose supplementation is beneficial. The medium was then optimized using response surface methodology based on the full factorial central composite design in a 3 l bioreactor. A $2^3$ factorial design augmented by 7 axial points (${\alpha}$ = 1.682) and 2 replicates at the center point was implemented in 17 experiments. A mathematical model was also developed to show the effect of each medium component and their interactions on the production of cell-associated tannase. The validity of the proposed model was verified, and the optimized medium was shown to produce maximum cell-associated tannase activity of 9.65 U/l, which is 93.8% higher than the activity in the basal medium, after 12 h at pH 5.0, $30^{\circ}C$. The optimum medium consists of 38 g/l lactose, 50 g/l tryptose, and 2.8 g/l gallic acid.

• 약학회지
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• 제42권1호
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• pp.59-69
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• 1998

To increase the solubility of quercetin, which is a practically insoluble flavonoid of Ginkgo biloba leaf, the effects of nonaqueous vehicles. Their cosolvents, water-sol uble polymers and modified cyclodextrins (CDs) were observed. Polyethylene glycols, diethyleneglycol monoethyl ether, and their cosolvents with water showed a good solvency toward quercetin. Also the aqueous solutions of povidone, copolyvidone and Cremophor RH 40 was effective in solubilizing quercetin. Complex formation of quercetin with ${\beta}$-cyclodextrin (${\beta}$-CD), dimethyl-${\beta}$-cyclodextiin (DMCD), 2-hydroxypropyl-${\beta}$-cyclodextrin (HPCD) and ${\beta}$-cyclodextrin sulfobutyl ether (SBCD) in water was investigated by solubility method at $37^{\circ}C$. The addition of CDs in water markedly increased the solubility of quercetin with increasing the concentration. AL type phase solubility diagrams were obtained with CDs studied. Solubilizaton efficiency by CDs was in the order of SBCD >> DMCD > HPCD > ${\beta}$-CD. The dissolution rates of quercetin from solid dispersions with copolyvidone, povidone and HPCD were much faster than those of drug alone and corresponding physical mixtures, and exceeded the equilibrium solubility (3.03${\pm}1.72{\mu}$g/ml). The permeation of quercetin through duodenal mucosa did not occur even in the presence of enhancers such as bile salts, but the permeation was observed when the mucus layer was scraped off. This was due to the fact that quercetin had a strong binding to mucin ($58.5{\mu}$g/mg mucin). However rutin was permeable to the duodenal mucosa. The addition of enhancer significantly increased the permeation of rutin in the order of sodium glycocholate.

• 한국환경과학회지
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• 제4권2호
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• pp.223-232
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• 1995

액체막의 운반체로 사용할 새로운 2개의 거대고리화합물을 합성하였다. 이들 결과들은 이 시스템을 구성하는데 있어서 이론의 응용성을 증명하여 준다. source phase의 공존이온으로서 $SCN^-$,$I^-$ 및 $Cl^-$이온을 그리고 receicing phases에서 $S_2O_3^{2-}$와 $P_2O_7^{4-}$을 이용한 액세막계로서부터 중금속 이온들에 대한 선택적 수송효율을 검토하였다. source phase의 M(II)이 $Cd(SCN)_2$$(P[SCN^-]= 0.40M)$, $Hg(SCN)_2([SCN^-]=0.40M)$, Pd(CN)$([CN^-]= 0.40M)$일때 M(II)의 수송율은 최대값을 나타낸다. 각가의 경쟁 양이온에 대한 Cd(II)이나 Pd(II)은 source phase가 00.3M-$S_2O_3^{2-}$이나 0.3M-$P_2O_7^{4-}$ 일때 가장 잘 분리된다.이 연구의 결과에서, 이 액체막계에서 효과적인 거대고리-매질수송을 하기 위해서는 두개의 규칙이 반드시 필요하다. 첫째, tiluence중으로 $M^{n+}$이온이 효과적으로 추출되고, 즉 만일 $M^{n+}$ 거대고리화합물 상호작용에 대한 logK값과 $M^{n+}$-거대고리화합물($L_1$이나 $L_2$)의 상호작용에 대한 logK값의 비가 충분히 크다면 receiving phase와 toluene의 접촉면으로부터 쉽게 중금속이온($Cd^{2+}$,$Pb^{2+}$ 및 $Hg^{2+}$)들이 떨어져 나온다. $L_1$(3,5-benzo-10,13,18,21-tetraoxa-1,7-diazabicyclo(8,5,5)eicosnan)은 $Cd^{2+}$ 과 $Pb^{2+}$ 이온과 안정한 착물을 형성한다. 그리고 $L_1$은 수용액중에서 용해하기가 매우 어렵다. 그리고 $Cd^{2+}$$L_1$나 $Pb^{2+}$$L_1$착물은 $Cd^{2+}-{(S_2O_3)}_2^{2-}$나 $Pd^{2+}-P_2O_7^{4-}$착물보다 비교적 불안정하다. 다른 한편으로 $Hg^{2+}-L_1$착물의 안정도는 $Hg^2-{2+}-(S_2O_3)_2^{2-}$이나 $Pb^{2+}-P0_2O_7^{4-}$의 그것보다 그리고 $L_2$(5,8,15,18,23,26-hexaoxa-1,12-diazabicyclo(10,8,8)octacosan)의 tuluene에 대한 분배계수는 $L_1$의 그것보다 훨씬 작다. 따라서 $Hg^{2+}$-$L_1$이나 $M^{n+}$이나 $M^{n+}-L-2(M^{2+}=Cd^{2+}, Pb^{2+}$이나 $Hg^{2+})$의 안정도수상수가 매우 큼에도 불구하고 이들 양이온의 수송량은 매우 적다.

• KSBB Journal
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• 제19권4호
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• pp.321-326
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• 2004

본 연구에서는 초임계 이산화탄소를 이용한 SAS 공정을 난용성 약물인 이트라코나졸과 친수성 물질인 HP-$\beta$-CD의 포접복합체 미세입자의 제조에 적용하기 위한 기초 연구를 수행하였다. 이트라코나졸과 HP-$\beta$-CD를 1:2의 몰비로 혼합한 용액을 사용하여 35∼$65^{\circ}C$의 온도범위와 83∼140 bar의 압력범위에서 SAS 공정으로 이트라코나졸/HP-$\beta$-CD 포접복합체 미세입자를 제조하였으며, 이트라코나졸 및 HP-$\beta$-CD 원재료의 열적 특성과 비교함으로써 초임계 유체 공정에 의해 포접복합체를 제조할 수 있음을 확인하였다. 또한, SAS 공정에 의해 제조된 이트라코나졸/HP-$\beta$-CD 포접복합체의 인공위액에 대한 이트라코나졸의 용출시험을 수행한 결과 이트라코나졸 원재료와 이트라코나졸을 함유한 대표적 시판 제제인 스포라녹스 캡슐제와 비교해 투입된 이트라코나졸의 50∼80%에 해당하는 양이 용출개시 5분 만에 방출되는 매우 빠른 초기 용출특성을 보임을 확인할 수 있었다. 이트라코나졸 /HP-$\beta$-CD 포접복합체의 제조시 SAS 공정 조건이 35$^{\circ}C$에서 $65^{\circ}C$로 높아짐에 따라 이트라코나졸의 용출률이 감소하였을 뿐만 아니라 열분석 결과 이트라코나졸의 용융 피크의 세기도 점차로 증가하게 된다는 결과로부터 포접복합체의 형성이 이루어지는 주변 매질의 온도가 높아짐에 따라 초임계 이산화탄소 분자의 활동도가 증가하게 되어 이트라코나졸과 HP-$\beta$-CD의 포접복합체 형성에 필요한 결합력이 점차로 약해져서 포접 효율이 저하하게 됨을 확인할 수 있었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.59-59
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• 2017

Rice (Oryza sativa L.) is the most important crop and its yield must be improved to feed the increasing global population. Recently developed high-yielding varieties with extra-large sink capacity often have a problem in unstable grain-filling. Therefore, understanding limiting factors for improving grain-filling and controlling them are essential for further improvement of rice grain yield. However, since grain-filling rate was determined by complex sink-source balance, the ability of grain-filling was very difficult to evaluate. Source ability for 'grain' was not only determined by the ability of carbon assimilation in leaves, but also that of carbon translocation from leaves to panicles. Sink strength was determined by the complex carbon metabolism from sucrose degradation to starch synthesis. Hence, to evaluate the grain-filling ability and determine its regulatory steps, the whole picture of carbon flow from photosynthesis at leaves to starch synthesis at grains must be revealed in a metabolite level. In this study, the yield and grain growth rate of three high-yielding varieties, which show high sink capacity commonly, were compared. Momiroman showed lower grain filling rate and slower grain growth rate than the other varieties, Hokuriku 193 and Tequing. To clarify the limiting point in the carbon flow of Momiroman, $CO_2$ labeled by stable isotope ($^{13}C$) was fed to three varieties during ripening period. The ratio of $^{13}C$ left in the stem was higher in Momiroman 24 hours after feeding, suggesting inefficient carbon translocation of Momiroman. More interestingly, $^{13}C$ translocation from soluble fraction to insoluble one in the grain seemed to be slower in Momiroman. To get the further insight in a metabolite level, we are now trying the $^{13}C$ labeling metabolome analysis in the developing grains.