• Title/Summary/Keyword: 반용매

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DFT 계산을 이용한 Buchwald-Hartwig amination 반응 메커니즘 연구

  • Gang, Seong-U
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.371-383
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    • 2014
  • 이 연구에서는 팔라듐 착물 $Pd(PPh_3)_2$을 사용한 bromotoluene과 morpholine간의 coupling reaction (Buchwald-Hartwig amination) 반응 메커니즘을 계산화학적 방법을 이용하여 연구하였다. 용매화 자유에너지를 고려한 중간체 에너지를 비교하였으며, 반응물질이 o-bromotoluene 일 때와 p-bromotoluene 일 때, 반응 중간체로 monophosphine 착물이 형성되는 경우와 bisphosphine 착물이 형성되는 경우를 비교하였으며, 반응 중간체로 bisphosphine 착물이 형성되는 경우 cis 이성질체가 중간체인 경우와 trans 이성질체가 중간체인 경우를 비교하였다. 그 결과, 반응물로 p-bromotoluene을 사용할 때 o-bromotoluene을 사용할 때보다 중간체가 상대적으로 더 안정하여 더 좋은 수득률을 얻을 수 있을 것으로 예상되었다. 또한 $Pd(PPh_3)_n(o-tolyl)(N(CH_2CH_2)_2O)$ (n=1 또는 2) 중간체를 제외하고는 모든 경우에서 bisphosphine 중간체가 형성되는 반응경로가 더 안정한 것으로 밝혀졌다. 그리고 $Pd(PPh_3)_2ArBr$의 경우 trans 이성질체가 cis 이성질체보다 안정하지만 $Pd(PPh_3)_2Ar(N(CH_2CH_2)_2O)$의 경우 반대로 cis 이성질체가 trans 이성질체보다 안정한 것으로 나타났다.

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STUDIES ON THE EXTRACTION OF SEAWEED PROTEINS 4. Precipitation Conditions and Nutritional Evaluation of Isolated Seaweed proteins (해조단백질 추출에 관한 연구 4. 추출단백질의 심전조건 및 영양적 평가)

  • WOO Soon-Im;RYU Hong-Soo;LEE Kang-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.12 no.4
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    • pp.225-234
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    • 1979
  • For the effective utilization of diverse and abundant resource of seaweeds in Korea as a food protein supplment, extraction conditions of water, salt, and alkali soluble proteins were investigated in previous work(Ryu and Lee, 1977: Lee et al., 1977: Lee et al., 1978). The present study as a part of the serial work was thus aimed to find the conditions of isolation and purification of extracted proteins, and to evaluate the nutritional quality of the isolated seaweed proteins in terms of amino acid composition, chemical score, protein score, modified essential amino acid index(MEAAI), and in vitro digestibility presented as pepsin-pancreatin digest residue index (PPDRI). As for the isolation of extracted proteins, TCA treatment was more effective for the proteins from rhodophyceae and Chlorophyceae while the precipitation at isoelectric point was more desirable for Phaeophyceae proteins. In amino acid composition, water soluble protein fraction was superior to the other fractions in Porphyra suborbiculata whereas both water and alkali soluble fractions seemed to bo more benefitial for Enteromorpha linza and Ulva pertusa; the extraction with alcohol-alkali mixed solvent for Undaria pinnatifida and Sargassum fulvellum. Glutamic acid and aspartic acid content was particularly high in all protein fractions examined. The total amino acid content of Porphyra suborbiculata and Enteromorpha linza was almost equivalent to that of dried whole egg although the essential amino acid content was lower. A comparative analysis was made on the inedexes between raw seaweed powder and isolated protein. Chemical score of Porphyra suborbiculata and Ulva pertusa was approximately 35 and 56 in cafes of raw powder and isolated protein respectively while only 10 to 16 for raw powder of Undaria pinnatifida and Sargassum fulvellum and 30 to 35 for their isolated proteins. Protein score of all isolated proteins was in the range of 63 to 73 which indicates that isolated protein would be mere valuable than the fern of raw seaweed powder. Digestibility by means of PPDRI was found to be extremely low in case of raw powder but it could be doubled in case of isolated protein yielding 67 to 70 for Porphyra suborbiculata and Ulva pertusa.

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Comparative analysis of nitrite scavenging activity and anti-inflammation effects in the fruiting bodies of medicinal mushrooms (약용버섯류 자실체의 아질산염 소거능 및 항염증 효능 분석)

  • Cho, Jae-Han;Lee, Gang-Hyo;Han, Jae-Gu;Kim, Hyung-Don;Jhune, Chang-Sung
    • Journal of Mushroom
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    • v.13 no.4
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    • pp.330-333
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    • 2015
  • This study was carried out to compare the anti-inflammation effects of various fruiting body of Ganoderma species and Cordyceps militaris, Phelinus linteus extracts. We concentrated Ganoderma species and other medicinal mushrooms by extracting with ethanol. And We made it $100{\mu}g/ml$ concentration. As a result of nitrite scavenging activity, in the contrast to the positive control; Ascorbic acid was 25%, ASI 7080 of Ganoderma species was disappeared up to around 40%. And in the contrast to Ascorbic acid was 55%, ASI 7002 was 78.5% that was the highest anti-inflammation effect in the result of "No assay test". The Cordyceps militaris showed 75% and Hericium erinaceus showed 59.7% of anti-inflammation effect. As a result of the fungus yield control test of $TNF-{\alpha}$ through ELISA method to ASI 7002 of Ganoderma species that showed the highest anti-inflammation, it was reduced as same as LPS non-treatment. We extracted RNA from ASI 7002 Ganoderma species 10, 50, $100{\mu}g/ml$ concentration and LPS $10{\mu}g/ml$ of Raw 264.7 cell. And we tested the expression of iNOS, COX-2 and TNF-a that are kinds of inflammation gene after synthesizing RNA with cDNA. Finally we could find that iNOS, COX-2 and TNF-a were all controlled expression in the result of above experiment.

Alteration of Recognition Sequence by Restriction Endonuclease -Effect of pH and Hydrophobicity on BamHI- (제한효소의 인식자리 변화 -BamHI 특이성에 미치는 산도와 소수성의 영향-)

  • 이강민
    • KSBB Journal
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    • v.11 no.2
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    • pp.193-200
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    • 1996
  • In molecular biology, type-II restriction endonuclease, which specifically recognize and cleave DNA at a limited number of sites, have been exploited as a means of characterizing DNA fragments, DNA mapping for genetic engineering. Type-II restriction endonucleases have been found to modulate their substrate specificity under modified conditions such as extreme pH, ionic strength, high enzyme concentration, substitution of metallic cofactors or addition of organic solvents. This study was initiated to investigate the modification of recognition specificity of BamHI according to the different pH and organic solvent under the given buffer condition. The specificity of BamHI is highly depends on the presence of hydrophobicity (LogP: partition coefficient) and pH of reaction solution. The specificity of BamHI is changed in range of LogP -1.03∼-1.35(at pH 7.5), -1.03∼-2.5 (at pH 8.0), -0.75∼-0.25(at pH 8.5), 0.32∼-2.5(at pH 8.9), respectively. Alteration of specificity appears in lower concentration of organic solvent when the reaction occurs in more alkali pH. For example, in DMSO solution, alteration of specificity appears in 20% concentration at pH 7.5 but in 4% concentration at pH 8.9.

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Change of Antioxidant Activity and Antioxidant Compounds in Saururus chinensis by Extraction Conditions (추출조건에 따른 삼백초 추출물의 항산화 활성 및 성분의 변화)

  • Kim, Suk-Kyung;Ban, So-Youn;Kim, Jun-Sung;Chung, Shin-Kyo
    • Applied Biological Chemistry
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    • v.48 no.1
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    • pp.89-92
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    • 2005
  • This study was conducted in order to establish the optimum extraction conditions in obtaining Saururus chinensis extracts. At the optimum extraction solvent (40% ethanol solvent), yield, DPPH, total phenolic compounds and total flavonoid in the extract of Saururus chinensis were 13.50%, 83.50%, 2.60 mg/ml and 2.09 mg/ml, respectively. At the optimum extraction time (4 hours), yield, DPPH, total phenolic compounds and total flavonoid in the extract of Saururus chinensis were 12.79%, 71.13%, 2.83 mg/ml and 2.16 mg/ml, respectively. At the optimum conditions (40% ethanol solvent and 4 hours), quercetrin and quercetin contents were 360.13 mg/100 g and 1379.54 mg/100 g, respectively. From the above results, we suggest that the optimum Saururus chinensis extract conditions are 40% ethanol solvent and 4 hours.

Multisample Extraction system for Solid Phase Extraction of Dissolved Organic Compounds from Sea Water (해수로부터 용존 윤기물의 Solid Phase Extraction을 위한 다수 시료 처리 장치)

  • Cho Ki Woong;Jung Kyungwha;Shin Jongheon;Kim Suk Hyun;Hong Gi-Hoon
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.3 no.3
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    • pp.34-40
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    • 2000
  • A multisample extraction device was newly designed for efficient extraction of dissolved lipophillic organic compounds from sea water sample. This device allowed extraction of organic compounds from up to 96 sample at a time using 96 multifolder on the principle of solid phase extraction with commercially available octadecyl silane (ODS) cartridges. The recovery yield of the new divice was higher than 90 % while that of conventional liquid-liquid extraction process are only 60 - 70 %. The amount of solvent required for the new device could be reduced to less than 20㎖ per 1ℓ of sample while 1 - 2 ℓ of solvent were used in the conventional liquid-liquid extraction process. The usefulness of this novel method was demonstrated with sea water samples collected from Yellow sea, and the qualitative and quantitative analyses results of the dissolved hydrocarbon showed this method was superior to that of conventional liquid-liquid extraction process in efficiency and reliability.

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Synthesis and Properties of Hyperbranched Polyester with Second-Order Outical Nonlinearity (2차 비선형 광학 초분지형 폴리에스테르의 합성 및 특성)

  • 이종협;이광섭
    • Polymer(Korea)
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    • v.25 no.6
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    • pp.803-810
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    • 2001
  • A nonlinear optical hyperbranched polyester (PE-Azo/Hyper) was synthesized from 4-[N,N-bis(hydroxyethyl)amino-4'-formyl] azobenzene and cyanoacetic acid by a Knoevenagel polycondensation using 4-(dimethylamino) pyridine as a base. The resulting polymer was soluble in polar aprotic solvents such as N,N-dimethylformamide and 1-methyl-2-pyrrolidinone and could be processed into optical quality films by spin coating. The molecular weight was determined to be $M_w$=61,800 ($M_W/M_n{=1.86}$) by gel permeation chromatography using polystyrene as a standard. No melting point was detected by differential scanning Calorimeter, indicating that this polymer presents an amorphous state. It shows a glass transition temperature of $121^{\circ}C$. The second-order nonlinear optical coefficient $d_{33}$ of the poled polymer determined by the second harmonic generation at 1064 nm was 25.4 pm/V.

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Screening for the Antioxidants in Unused Marine Resources by the Polarographic Method (수산 미이용자원 중에 존재하는 항산화 물질의 검색)

  • Cho, Soon-Yeong;You, Byeong-Jin;Chang, Mi-Hwa;Lee, Soo-Jung;Sung, Nak-Ju;Lee, Eung-Ho
    • Korean Journal of Food Science and Technology
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    • v.26 no.4
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    • pp.417-421
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    • 1994
  • To detect naturally occurring antioxidative components from unused marine resources, the screening test for the antioxidants containing in starfish, ascidian skin, cuttlefish ink, echinoid skin, Sargassum horneri, Agarum cribrosum, Odonthalia corymbifera and Desmarestia ligulata was carried out. The ether, acetone and methanol fractions successively extracted from Odonthalia corymbifera were very effective on prevention of the nonenzymatic lipid oxidation and their $IC_{50}$, (a concentration to inhibit 50% of control lipid oxidation rate) were $30,\;100\;and\;200{\mu}g/ml$, respectively. The water and methanol extracts obtained from cuttlefish ink also revealed strong antioxidant effect and their $IC_{50}$, were $390,\;100{\mu}g/ml$, respectively.

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Simultaneous analysis of 12 kind maker components in Banhabaekchulchhonma-tang by RP-HPLC (RP-HPLC를 이용한 반하백출천마탕에서 12종 지표성분의 동시분석)

  • Lee, Kwang Jin;Yang, Hye Jin;Ma, Jin Yeul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.7
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    • pp.4682-4691
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    • 2014
  • Banhabaekchulchhonma-tang is a traditional Korean herbal prescription with a range of pharmacological activities. In this study, the simultaneous analysis of 12 kinds of marker components, Homogentisic acid, Hesperidin, Naringin, Alisol A, Atractylenolide II, Atractylenolide III, Ginsenoside Rg1, Formononetin, Gastrodin, Berberine, Palmatine and 6-gingerol, in Banhabaekchulchhonma-tang was performed using high-performance liquid chromatography (RP-HPLC). The standard sample of commercial $C_{18}$ reversed phase-column using water (0.1% TFA) and acetonitrile as the mobile phase with a step gradient elution mode. The flow rate (1.0mL/min), injection volume ($10{\mu}L$) and column oven temperature ($40^{\circ}C$) at a 200, 220, 280 and 340nm wavelength was conducted. All calibration curves of the standard components showed good linearity ($r^2$ >0.999). In addition, the limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.012 to $0.878{\mu}g/mL$ and 0.009 to $0.290{\mu}g/mL$. The precision intra-day and inter-day were ranged from 0.07 to 1.21% and 0.20 to 0.90%, respectively. The recoveries ranged from 97.17 to 108.40%. Each sample amount showed a very small change. These results highlight the efficient quality evaluation of Banhabaekchulchhonma-tang.

Effect of Linkage Groups on the Properties of Semi-flexible Liquid Crystalline Polymers (연결기가 반 유연성 액정중합체의 물성에 미치는 영향)

  • Park, Jong-Ryul;Yoon, Doo-Soo;Bang, Moon-Soo
    • Applied Chemistry for Engineering
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    • v.26 no.4
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    • pp.445-451
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    • 2015
  • Semi-flexible liquid crystalline polymers containing a mesogenic group and an octamethylene flexible spacer in the main chain were synthesized by solution polycondensation. The mesogenic group in the polymer consists of four aromatic rings connected by ester and ketone, ether, sulfide, methylene, sulfone, or isopropylidene linkage groups. This paper discusses effects of the central linker of the mesogenic group on polymer properties. The structures and properties of synthesized polymers were investigated by $^1H$-NMR, FT-IR, differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), X-ray diffractometer (XRD), and polarizing optical microscope (POM). Polymers having bent linkage groups exhibited low thermal transition temperatures, narrow mesophase temperature ranges, low liquid crystallinity, and good solubilities in organic solvents, while those having bulky linkage groups were amorphous and exhibited high glass transition temperatures.