• 한국산학기술학회논문지
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• 제10권4호
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• pp.852-856
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• 2009

Poly(ethyleneglycol methacrylate-co-benzyl methacrylate) (P(PEGMA-co-BMA) 마이크로겔을 폴리아크릴산 용액에서 PEGMA와 벤질 메타아크릴레이트를 침전중합법으로 합성하였다. 다양한 입자 크기를 갖는 마이크로겔은 폴리아크릴산 및 모노머의 농도, 용매의 성질에 따라 합성하였다. P(PEGMA-co-BMA) 마이크로겔의 입자 크기는 폴리아크릴산의 농도가 증가할수록 감소하였고 모노머의 농도가 증가할수록 증가하였다. 또한 용매의 용매 파라메타의 값이 증가할수록 입자의 크기는 증가하였다. 그리고 P(PEGMA-co-BMA) 마이크로겔의 크기는 실험 조건에 따라 $0.1{\mu}m$에서 $0.35{\mu}m$까지 조절할 수 있었다.

• 대한화장품학회지
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• 제40권1호
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• pp.89-94
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• 2014

물푸레나무 수피 추출물은 주요 생활성 물질로서 esculetin과 esculin을 포함하고 있다. 이 가운데, Esculetin은 B16F10 melanoma cells에서 $IC_{50}$ value $2.8{\mu}M$의 아주 좋은 melanogenesis 억제 활성을 나타내며, 이를 통해 Melan-A cell에서 melanin 합성을 감소시킨다. 더욱이, esculetin은 mushroom tyrosinase에서도 $IC_{50}$ value $40{\mu}M$의 억제 활성을 나타내어 melanin biosynthesis를 저해한다. 위의 결과들로서, 우리는 melanogenic enzyme 활성 조절에 의해 melanin 생성을 저해하는 효과적인 피부미백 물질로서 esculetin을 제안하고자 한다.

• Korean Chemical Engineering Research
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• 제43권6호
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• pp.691-695
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• 2005

종이 필터, 면섬유, 유리섬유 필터 등과 같은 지지체 위에 이차성장 수열합성법에 의하여 제올라이트 박막을 제조하였다. 먼저, 제올라이트 종자로 사용하기 위하여 제올라이트 NaA(${\approx}0.5{\mu}m$)와 silicalite-1(${\approx}0.2{\mu}m$) 결정들을 합성하였고, 이 결정들을 지지체의 표면에 화학결합을 이용하여 부착시켰다. 종자 결정으로 덮힌 지지체 위에 NaA나 silicalite-1 제올라이트 박막이 생성되었으며, 제조된 박막은 주사형 전자현미경으로 관찰하였고, X-ray 회절로 분석하였다.

• 한국균학회지
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• 제37권1호
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• pp.111-113
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• 2009

싸리버섯은 한국에서 상업적으로 중요한 외생균근성 버섯중 하나로 자연채취하고 있다. 본 연구는 소나무 유묘에 싸리버섯균을 접종하여 균근형성을 시도하였다. 소나무 유묘에 형성된 싸리버섯 균의 외생균근은 단순형과 차상분지형이였다. 외생균근의 직경은 $325-380{\mu}m$ 이었고, 균투층은 반투명색으로 $20-30{\mu}m$ 이었다. 한편, 싸리버섯 균의 균사생장 최적온도는 $25^{\circ}C$ 이였고, PDA 배지에서 2달간에 5 cm 정도 생장하였다.

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.1918-1923
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• 2016

Two baicalein derivatives, baicalin and oroxylin A, were synthesized in this study. These derivatives exhibit diverse biological activities, such as anxiolytic and anticancer activities as well as memory enhancement. In order to synthesize baicalin from aglycon baicalein using Escherichia coli, we utilized a glycosyltransferase that regioselectively transfers glucuronic acid from UDP-glucuronic acid to the 7-hydroxy group of baicalein. To increase baicalin productivity, an araA deletion E. coli mutant, which accumulates UDP-glucuronic acid, was used, and ugd, which converts UDP-glucose to UDP-glucuronic acid, was overexpressed. Using these strategies, approximately $720.3{\mu}M$ baicalin was synthesized from $1,000{\mu}M$ baicalein. Oroxylin A was then synthesized from baicalein. Two O-methyltransferases (OMTs), ROMT-15 and POMT-9, were tested to examine the production of oroxylin A from baicalein. E. coli harboring ROMT-15 and E. coli harboring POMT-9 produced reaction products that had different retention times, indicating that they are methylated at different positions; the structure of the reaction product from POMT-9 was consistent with oroxylin A, whereas that from ROMT-15 was 7-O-methyl baicalein. Using E. coli harboring POMT-9, approximately 50.3 mg/l of oroxylin A ($177{\mu}M$) was synthesized from 54 mg/l baicalein ($200{\mu}M$).

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1793-1798
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• 2003

A series of amorphous molecules that possess both photoconductive and electro-optic properties was synthesized in order to investigate photorefractive properties of bifunctional organic-glasses. Diethylaminobenzaldehyde-diphenylhydrazone was covalently attached to 5-(4-diethylamino-benzylidene)-1,3-dimethylpyrimidine-2,4,6-trione through a flexible alkyl chain (3, 4, 5, 6 and 10 carbons) containing two ether linkages. The longer linkage not only lowered the glass transition temperature ($T_g$) of the molecules, but also allowed faster orientation of the chromophore. To examine the photorefractive properties, a 50 ${\mu}$m-thick film was prepared from the mixture of a bifunctional molecule, butyl benzyl phthalate, and $C_{60}$. The photoconductivity of this composite was as high as $8.01\;{\times}\;10^{-12}$ S/cm at 60 V/ ${\mu}$m, and the maximum diffraction efficiency ( ${\eta}_{max}$) of 50 ${\mu}$m-thick film was about 5% at 80 V/ ${\mu}$m.

• 한국세라믹학회지
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• 제36권1호
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• pp.36-42
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• 1999

2단계 열탄소환원법으로 탄화규소 휘스커를 기상-고상, 2단계, 기상-액상-고상 성장기구로 각각 합성하였다. 그리고 휘스커에 있는 적층결합을 X-ray와 투과전자현미경을 이용하여 분석하였다. 탄화규소 휘스커에 있는 적층결함은 휘스커의 지름과 상관관계가 있는 것으로 나타났다. 즉, 기상-고상, 2단계 성장, 기상-액상-고상 성장기구에 상관없이 지름이 1$\mu\textrm{m}$이하로 작아지는 경우 적층결합이 많아지고, 기상-액상-고상 기구로 성장한 지름이 2$\mu\textrm{m}$보다 큰 경우 적층결함이 거의 없는 것으로 나타났다. 이같은 현상은 휘스커 지름이 작아짐에 따라 휘스커의 비표면적이 증가하는 때문인 것으로 판단되었다.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1898-1906
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• 2004

Nonclassical quinazolinone analogs I, II, and III, in which the glutamic acid moiety of the classical antifolates is substituted by phenylglycine, phenylalanine or aminobenzoic acid and their methyl esters, were synthesized and evaluated as lipophilic inhibitors of thymidylate synthase (TS). The target compounds were generally potent inhibitors of L. casei and human TS with $IC_{50}$ values within the narrow range of 0.2-10 ${\mu}$M and 0.003-0.03 ${\mu}$M, respectively. Further, most of the target compounds showed cytotoxicity against tumor cell lines of murine and human origin with $IC_{50}$ values of as low as 0.050 ${\mu}$M. Substitution of another hydroxyl or carboxylic acid/ester group at the phenyl ring further increased the potency of TS inhibition and cell growth inhibition. Most effective were compounds If and Ic in which extra carboxylic acid/ester was present at the phenyl ring with nanomolar $IC_{50}$ values of 0.0044 and 0.0093 ${\mu}$M against human TS and submicromolar cytotoxic growth inhibition against all four tumor cell lines.

• Journal of Plant Biology
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• 제27권3호
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• pp.139-147
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• 1984

This in vitro study was employed to clarify the effects of several pollutants i.e. $SO_2$, fluoride, cadmium(Cd), aluminum(Al) and NaCl, on the organogenesis and growth responses of shoot-tip, stem and multiple-buds segments derived from hypocotyl or cotyledon culture of petunia seedlings. ${Na_2}{SO_3}$levels of more than 200$\mu{g}$/ml had significantly reduced organogenesis, growth, and chlorophyll content. The injuries caused by ${Na_2}{SO_3}$, concentration of more than 400$\mu{g}$/ml were alleviated by increasing hydrogenion concentration of medium, indicating some relationship between two factors. Organogenesis was not affected by the fluoride concentration up to 100ppm in the media, but the growth and chlorophyll content were greatly reduced by the fluoride. The effect of Cd depended on the explant sources used for the culture; 1.0ppm was effective for fresh weight increase in shoot tip culture, and 3.0ppm in stem segments culture. Organogenesis and growth were greatly reduced by more than 10.0 Cd treatment. Growth and formation of shoots were better with Na conc. of 0.3% compared to control, but those of roots were inhibited. Na concentration goes over 1.0%, organogenesis and subsequent growth were inhibited, and chlorophyll synthesis was drastically reduced. Chlorophyll content was increased on the medium supplemented with Al 50$\mu{g}$/ml compared to control. However the formation and growth of shoots were greatly inhibited with more than 400$\mu{g}$/ml and roots were not produced at all.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3684-3692
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• 2010

A series of azole-containing piperazine derivatives have been designed and synthesized. The obtained compounds were investigated in vitro for their antibacterial, antifungal and cytotoxic activities. The preliminary results showed that most compounds exhibited moderate to significant antibacterial and antifungal activities in vitro. 1-(4-((4-chlorophenyl) (phenyl)methyl)piperazin-1-yl)-2-(1H-imidazol-1-yl)ethanone and 1-(4-((4-Chlorophenyl)(phenyl)methyl)piperazin-1-yl)-2-(2-phenyl-1H-imidazol-1-yl)ethanone gave remarkable and broad-spectrum antimicrobial efficacy against all tested strains with MIC values ranging from 3.1 to $25\;{\mu}g/mL$, and exhibited comparable activities to the standard drugs chloramphenicol and fluconazole in clinic. Moreover, 2-((4-((4-chlorophenyl)(phenyl)methyl)piperazin-1-yl)methyl)-1H-benzo[d]imidazole was found to be the most effective in vitro against the PC-3 cell line, reaching growth inhibition values (36.4, 60.1 and 76.5%) for each tested concentration: $25\;{\mu}g/mL$, $50\;{\mu}g/mL$ and $100\;{\mu}g/mL$ in dose-dependent manner. The results also showed that the azole ring had noticeable effect on their antimicrobial and cytotoxic activities, and imidazole and benzimidazole moiety were much more favourable to biological activity than 1,2,4-triazole.