• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2193-2198
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• 2011

We prepared polycatenar 1H-imidazole amphiphiles having a structure in which a 1H-imidazole head was connected through a benzene ring to a pheny group having two or three oligo(ethylene glycol) chains and studied their supramolecular assembly by fluorescence spectroscopy, transmission electron microscopy (TEM) and atomic force microscopy (AFM). When the aqueous solutions of the amphiphiles ($5{\times}10^{-5}M{\sim}10^{-3}M$) were deposited onto a carbon-coated copper grid and dried, twisted structures with diameters of ~200-300 nm were imaged by TEM and AFM. We presume that the structures comprised a chain of the amphiphile dimers formed via successive hydrogen bonding between the 1H of the imidazole group and 3N of the neighboring one. In a solution of pH 4, entangled fibers with diameters of several nanometers were observed by TEM. In a pH 10 solution, film-like aggregates formed exclusively. The 1H-imidazole amphiphiles hydrolyzed tetraethoxysilane to induce gelation to form fibrous and spherical silica structures at neutral pH in aqueous solutions. No silica was formed when imidazole was used instead of the amphiphiles, suggesting that the selfassembled aggregates of the amphiphiles were responsible for the gelation.

• Journal of Ginseng Research
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• 제10권2호
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• pp.209-217
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• 1986

Yeast alcohol dehydrogenates and ginseng saponin interaction has been investigated to understand the non-specific enzyme stimulating effect of the saponin of Panax ginseng C.A. Meyer. It was confirmed that several amphiphiles such as sodium dodecyl sulfate(SDS), Triton X-100, sodium taurodeoxycholate (Na-TDC) as well as ginseng saponin mixture and purified ginseng glycosides lowered Km values of yeast alcohol dehydrogenase (ADH) for ethanol and NAD in the presence of the above amphiphiles suggesting that the surface activity of the amphiphiles might play a significant role in the ADH catalyzed reactions. Conformational change of yeast alcohol dehydrogenase in the presence of the above amphiphiles at their optimal concentration for the maximum activity was studied. Circular dichroism (C.D) spectrum of yeast ADH showed that the conformational change of the enzyme occurred in the presence of above amphiphiles. Fluorescence data also showed that the hydrophobic area increased in the presence of above amphiphiles. Examination of the interaction between ADH and ginseng saponin using radioactive saponin showed that there might be a very weak interaction between them. From the above results, it was concluded that the non-specific enzyme stimulating effect of the saponin might be due to the change of polarity of the enzyme solution in the presence of the saponin.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.557-557
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• 2012

Silicatein-${\alpha}$, the enzyme extracted from silica spicules in glass sponges, has been studied extensively in the way of chemistry from 1999, in which the pioneering work by Morse, D. E. - the discovery of the enzymatic hydrolysis in Silicatein-${\alpha}$ - was published. Since its reaction conditions are physiologically favored, synthesis of various materials, such as gallium oxide, zirconium oxide, and silicon oxide, was achieved without any hazardous wastes. Although some groups synthesized oxide films and particles, they have not achieved yet controlled morphogenesis in the reaction conditions mentioned above. With the knowledge of catalytic triad involved in hydrolysis of silicone alkoxide and oligomerization of silicic acid, we designed the novel peptide amphiphiles to not only form self-assembled structure, but also display similar activities to silicatein-${\alpha}$. Designed templates were able to self-assemble into left-handed helices for the peptide amphiphiles with L-form amino acid, catalyzing polycondensation of silicic acids onto the surface of them. It led to the formation of silica helices with 30-50 nm diameters. These results were characterized by various techniques, including SEM, TEM, and STEM. Given the situation that nano-bio-technology, the bio-applicable technology in nanometer scale, has been attracting considerable attention; this result could be applied to the latest applications in biotechnology, such as biosensors, lab-on-a-chip, biocompatible nanodevices.

• Bulletin of the Korean Chemical Society
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• 제19권11호
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• pp.1249-1252
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• 1998

• Bulletin of the Korean Chemical Society
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• 제30권9호
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• pp.2101-2106
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• 2009

A series of facial amphiphiles 3,7-diaminocholestane were synthesized from 3,7-diketocholestane via 2 sequential reductive aminations and anion recognition was evaluated with acetate, chloride, bromide, fluoride and phosphate anions. The stereo-selective reductive amination protocol was utilized to synthesized facial amphiphiles afforded receptors in high yields. The molecular receptor 2 showed the highest binding constant with acetate in a 1:1 ratio.

• 멤브레인
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• 제5권2호
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• pp.89-96
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• 1995

Azobenzene기를 가지는 인산형 양친매성 화합물의 기/액 계면에 있어서으 단분자막 거동이 $\pi-A$ 곡선 및 표면흡수스펙트라로 검토되었다. 분자간의 강한 수소결합력을 가지는 이 화합물들은 수면에 전개 후 즉시 결정화하여 단분자막 domain들을 형성한 회합체 흡수스펙트라를 나타내었다. 그러나 subphase의 조건(분자량이 큰 유가염의 첨가 및 pH의 상승)을 변화시킴에 의해 결정 domain 형성을 제어하는 것이 가능하였다. 한편, 금속이온 첨가는 인산령 양친매성 단분자막의 분재배향상태를 변화시켰다. 금속이온의 전하가 높을수록 ($1\leq2$ < 3 < 4 가), azobenzene기를 가지는 양친매성 화합물의 분자상태가 tilt된 배향성에 기인하는 장파장으로 이동한 흡수극대를 나타내었다. 이것은 서로 다른 전하를 가진 금속이온을 흡착시킴에 의해 단분자막의 분자배향성을 변화시켜, 단분자막의 집합상태 제어 가능성을 시사한다.

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1270-1282
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• 2006

• Bulletin of the Korean Chemical Society
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• 제31권3호
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• pp.549-550
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• 2010

• 한국식품조리과학회지
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• 제10권1호
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• pp.8-12
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• 1994

본 연구에서는 무설탕 무지방의 저칼로리 케익에서 다량으로 첨가되는 유화제의 양을 감소시키기 위하여, 다양한 종류의 유화제를 1.5온 혹은 15% 첨가수준에서 가수전처리 하거나, 전처리 하지 않은 경우가 저칼로리 케익에 미치는 영향을 조사하였다. 물리 화학적인 특성 및 관능검사에 사용된 유화제는 Vanall$^{R}$, sorbitan me-nostearate, polysorbate 60, distilled monoglyceride, su-crose ester F10, SE F7O 및 SE F160이다. 반죽에서 낮은 비중을 나타내고 안정된 분산 체계를 유지하여 케익 volume이 커진 경우는 고수준으로 전처리된 SMS, MG, SE Fl60 및 F70가 첨가된 케익군과 저수준으로 전처리된 SE Fl6O, F7O 및 PS 60가 첨가된 케익군이다. 전처리하여 저수준으로 SE Fl60, F70 및 PS 60을 첨가하여 케익을 만들 경우 부드러운 케익이 되며, 고수준으로 전처리하지 않고 VanallR 을 첨가한 케익과 비슷한 부피를 지닌 케익을 만들었다.

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2704-2710
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• 2014

Catalase (CAT) decomposes hydrogen peroxide that is toxic to the body. In this study, simple and sensitive detector has been developed for observing catalase activity using liquid crystal droplet system. Microscale LC droplet patterns are formed by spreading aldehyde-doped nematic liquid crystal on pre-treated glass slides. When hydrogen peroxide is added, aldehyde is oxidized and amphiphiles are formed. Dodecanoates cause the pattern to transit from bright to dark as they self-assemble to form a carboxyalte monolayer at the interface. When a drop of pre-incubated CAT and hydrogen peroxide mixture is placed onto the pattern, bright fan-shape is observed. This planar optical appearance indicates that catalase has decomposed hydrogen peroxide. Compared to the detectors that have been previously developed, this system is more sensitive with detection limit of 1fM. This research suggests further studies to be on LC droplet patterning to develop highly sensitive and methodologically simple sensors for various chemicals.