헛개나무 열매로부터 유용 화합물의 단리.동정 및 생리활성 평가

서진아(Jin Ah Seo),고은희(Eun Hee Koh),정하숙(Ha Sook Chung) 한국차학회 2022 한국차학회지 Vol.28 No.1

헛개나무 열매를 열수 추출 후 건조시킨 분말을 80% EtOH로 추출한 추출물을 농축하여 획득한 CHCl3, EtOAc 및 n-BuOH 가용성 획분을 실험재료로 silica gel 및 Sephadex LH-20 column chromatography를 반복 시행하여 화합물 1∼5를 단리하였다. UV-Vis, LC-ESI-MS (negative ion) 및 1 H-1 H COSY, DEPT, HMQC 및 HMBC 분석을 통해 화합물의 화학구조를 5-hydroxy-2-hydroxymethyl-4-pyrone (1), 5-hydroxy methyl-2- furaldehyde (2), 5-(3-acetylpropionate)methyl-2-furaldehyde (3), 3,5-dihydroxy-3,4,5,6-tetrahydro-2-pyranone (4) 및 (4-(3-ethoxy)- pyridyl)methanol-β-D-glucopyranoside (5)로 동정하였다. 화합물 1과 2의 DPPH radical-scavenging 활성(IC50, μM) 은 각각 19.48 ± 1.02 및 32.07 ± 1.64를 나타내었고, 화합물 1의 tyrosinase 저해 활성(IC50, μM)은 19.17 ± 0.72를나타내었다. 이번 실험을 통해, 헛개나무 열매에 함유된 화합물 1이 항산화 효능이 우수한 유용물질임을 확인하였으며, 대용차 개발 시 기능성 소재로서의 활용 가능성을 확인하였다. This study was conducted to identify bioactive components with DPPH radical-scavenging and tyrosinase inhibitory activities from the fruits of Hovenia dulcis Thunb. The studies consisted of the extraction and solvent fractionation, and isolation of compounds 1~5 from chloroform, ethyl acetate and n-butanol-soluble fractions. Chemical structures were identified as 5-hydroxy-2-hydroxymethyl-4-pyrone (1), 5-hydroxymethyl-2-furaldehyde (2), 5-(3-acetylpropionate)-methyl-2-furaldehyde (3), 3,5-dihydroxy-3,4,5,6-tetrahydro-2-pyranone (4) and 4-(3-ethoxy)- pyridyl-methanol-β-D-glucopyranoside (5), respectively, using UV–visible spectrophotometry (UV-Vis), liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), proton nuclear magnetic resonance ( 1 H-NMR), carbon-13 nuclear magnetic resonance (13C-NMR), 1 H-1 H correlated spectroscopy (COSY), distortionless enhancement by polarization transfer (DEPT), heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bonding connectivity (HMBC) spectral data. Compounds 1 and 2 showed moderate antioxidant effect with IC50 values of 19.48 ± 1.02 μM and 32.07 ± 1.64 μM in 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity, respectively. In addition, compound 1 exhibited strong mushroom tyrosinase inhibitory activity with IC50 value of 19.17 ± 0.72 μM.

미술수업에서의 낭만단계에 관한 연구

서진아(Seo Jin ah) 한국미술교육학회 2017 美術敎育論叢 Vol.31 No.1

미술수업에서 낭만단계는 학생들에게 다양한 미적 경험을 가능하게 하는 중요한 단계이다. 따라서 본 연구는 화이트헤드의 지각론을 기반으로 미술수업의 낭만단계 특징을 정의하고, 낭만단계의 특징이 보이는 미술수업을 선정하여 수업이 어떻게 전개되는지를 분석하는 것을 목적으로 한다. 우선 미술수업의 낭만단계의 특징을 분석한 결과, 신체는 예술을 생산하기 위한 하나의 도구로 경험이 신체를 관통해서 의식 경계에서 오는 느낌을 작품으로 풀어놓는 역할을 한다. 따라서 낭만단계에서는 ‘학생들의 신체를 통한 지각’이 중요하다. 그리고 교사는 학생들이 ‘지각하는 환경을 제한’함으로써 학생들이 예술가들처럼 지각할 수 있는 경험을 제공할 수 있다. 마지막으로 교사는 ‘소극적 교육’을 통하여 학생 활동의 자유를 보장하는 것이다. 이러한 특징을 보이는 ㄱ 중학교 L 교사의 수업을 참관하고 분석한 결과3개의 큰 사이클과 그 안에 작은 사이클 들이 동시에 존재하였다. 학생들은 미술수업의 낭만단계에서 경험하는 느낌에 대해 즐겁게 반응하고 수많은 이야기를 쏟아내고 있었으며 이는 바로 작품제작으로 이어졌다. 수업 참관과 인터뷰한 내용을 분석한 결과 낭만단계가 활성화된 수업이 가능할 수 있었던 이유는 다음과 같다. 첫째 일상적 사고가 가능한 환경을 제한하고 익숙하지 않은 수업 환경을 만들거나 정해진 재료에 집중하게 하여 학생들이 예술가처럼 지각할 수 있도록 한 것이다. 둘째 학생들의 자유로운 활동과 가치판단을 존중하고 보장한 것이다. 마지막으로 수업에 대해 지속적으로 고민하고 연구하였다. 그리고 이렇게 만들어진 수업은 학생들에게 미적 경험과 큰 감동을 주었다는 것을 학생 인터뷰와 설문조사를 통해 확인할 수 있었다. The romantic stage in art class is an important one that enables students to have a variety of aesthetic experiences. Thus, this study aims to define the characteristics of the romantic stage in the art class on the basis of the perception theory of Whitehead, and to analyze how the class develops with selecting the art class which shows the characteristics of the romantic stage. First of all, as a result to analyze the characteristics of the romantic stage of the art class, The human body, as an instrument for the producion of art, plays a role to release the feeling of experience which comes from the boundary of consciousness penetrating the body. Therefore, in the romantic stage, ‘perception through the students’ body’ is important. In addition, ‘limiting the perceived environment’ of students enables students to perceive like artists. Lastly, it is to ensure the freedom of students’ activity through the ‘negative education’. As an result to participate and analyze the middle school class of a teacher, L, which shows such characteristics, there existed four big cycles and small cycles in them at the same time. The students responded happily to the feelings that they experiencing the romantic stage of the art class and were pouring a lot of stories, ant this led to the production of the work. As a result of analyzing the the inspection of an instruction and the contents of interviews, the endeavor of a teacher, Lee, to enable the class where the romantic stage to be active is like this. First, to limit the environment in which everyday thinking is possible and make an unfamiliar classroom environment, or to enable the students to focus on the designated materials so that the students are able to perceive as an artist. Second, it is to respect and ensure the free activities and value judgment of students. The last one is consistently to have agonized and studied over the class. Then, it was able to be confirmed through the interviews with students and the questionnaires that the class lesson made in this way gave students aesthetic experience and great impression.

미술 수업에서 장치(dispositif)의 의미

서진아(Seo, Jin Ah) 한국미술교육학회 2020 美術敎育論叢 Vol.34 No.1

The purpose of this study is to explore the mining of apparatus(dispositif) in art class through the concept of Foucault, Deleuze and Agamben in order to have a deeper understanding and interpretation of art class. The concept of apparatus addressed in this paper is based on the work of Foucault and further studies of Deleuze and Agamben. Through this, the apparatus in art class can be understood. The apparatus of art class consists of heterogeneous elements, physical and non-physical, and operates by the force acting on the relationship between these elements. Therefore, the art class is performed by the teacher adjusting and arranging the elements of the art class apparatus. At this time, The art class is changed by rearrangement, in consideration of the physical elements of the art class as well as the non-physical elements behind those. This change in art class provides students with the opportunity to redistribute their aesthetic systems by creating places of new aesthetic experiences. This aim of this study is to change to a better art class through this. 본 연구는 미술 수업을 좀더 깊이 이해하고 해석할 수 있는 관점을 갖기 위해 푸코와 들뢰즈, 아감벤의 장치(dispositif)의 개념을 통해 미술 수업의 장치의 의미를 살펴보는 것을 목적으로 한다. 장치 개념은 대표 학자인 푸코와 그의 장치 개념을 확장하여 논의하고 있는 들뢰즈, 아감벤의 연구를 중심으로 살펴보았다. 이를 통해 미술 수업의 장치를 이해할 수 있었다. 미술 수업의 장치는 물리적 요소와 비물리적 요소인 이질적인 요소로 이루어졌으며 이 요소들 사이의 관계에서 작용하는 힘을 통해 작동한다. 다시말하면 미술 수업은 교사가 미술 수업 장치의 요소들을 조절하고 배치하면서 이루어지는 것이다. 이때 미술 수업의 물리적 요소뿐만 아니라 그 이면의 비물리적 요소를 고려하여 이전과 다르게 배치함으로써 미술 수업은 변화하게 된다. 이러한 수업의 변화는 학생들에게 새로운 미적 경험의 장을 조성함으로써 그들의 미학적 체계를 새롭게 분할할 수 있는 기회를 제공할 것이다. 본 연구는 이를 통해 좀더 나은 미술 수업으로의 변화를 모색하고자 한다.

Synthesis of Porous $TiO_2$ Thin Films Using PVC-g-PSSA Graft Copolymer and Their Use in Dye-sensitized Solar Cells

변수진,서진아,지원석,설용건,김종학,Byun, Su-Jin,Seo, Jin-Ah,Chi, Won-Seok,Shul, Yong-Gun,Kim, Jong-Hak The Membrane Society of Korea 2011 멤브레인 Vol.21 No.2

원자전달 라디칼 중합(ATRP)에 의해 poly(vinyl chloride) (PVC) 주사슬과 poly(styrene sulfonic acid) (PSSA) 곁사슬로 되어있는 양쪽성 PVC-g-PSSA 가지형 공중합체를 합성하였다. PVC-g-PSSA 가지형 공중합체 고분자를 템플레이트로 사용하고 졸겔법을 적용하여, 결정성 아타네제상의 미세기공 이산화티타튬 필름을 제조하였다. $TiO_2$ 전구체인 TTIP를 친수성인 PSSA 영역과 선택적으로 작용시켜 $TiO_2$ 메조기공 필름을 성장하였으며, 이를 주사전자 현미경 (SEM)과 엑스레이회절 (XRD)분석을 통해 분석하였다. 스핀코팅 횟수와 P25 도입에 따른 염료감응 태양전지 성능을 체계적으로 분석하였다. 그 결과 준고체 고분자 전해질을 이용하였을 때, 100 mW/$cm^2$ 조건에서 에너지 변환 효율이 2.7%에 이르렀다. An amphiphilic graft copolymer comprising a poly(vinyl chloride) (PVC) backbone and poly (styrene sulfonic acid) (PSSA) side chains (PVC-g-PSSA) was synthesized via atom transfer radical polymerization (ATRP). Mesoporous titanium dioxide $(TiO_2)$ films with crystalline anatase phase were synthesized via a sol-gel process by templating PVC-g-PSSA graft copolymer. Titanium isopropoxide (TTIP), a $TiO_2$ precursor was selectively incorporated into the hydrophilic PSSA domains of the graft copolymer and grew to form mesoporous $TiO_2$ films, as confirmed by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The performances of dye-sensitized solar cell (DSSC) were systematically investigated by varying spin coating times and the amounts of P25 nanoparticies. The energy conversion efficiency reached up to 2.7% at 100 mW/$cm^2$ upon using quasi-solid-state polymer electrolyte.

Preparation of Ag Nanoparticles by Templating Poly(vinyl chloride)-g-poly(styrene sulfonic acid) Graft Copolymer Membrane

변수진,서진아,지원석,설용건,김종학,Byun, Su-Jin,Seo, Jin-Ah,Chi, Won-Seok,Shul, Yong-Gun,Kim, Jong-Hak The Membrane Society of Korea 2011 멤브레인 Vol.21 No.1

원자전달 라디칼 중합(ATRP)에 의해 poly(vinyl chloride) (PVC) 주사슬과 poly(styrene sulfonic acid) (PSSA) 곁사슬로 되어있는 양쪽성 PVC-g-PSSA 가지형 공중합체를 합성하였다. 합성된 고분자 전해질막을 10 wt% $AgNO_3$ 수용액에 담가 은이온으로 이온교환을 하였으며, 환원제를 통하여 은 나노입자를 성장시켰다. UV분광학과 XRD 분석을 통해 은 나노입자 성장을 확인하였다. 투과전자현미경(TEM) 분석결과 $NaBH_4$를 사용하였을 때 10~20 nm 크기의 은 나노입자를 얻는데 가장 효과적임을 알 수 있었다. 또한 은 나노입자의 성장은 환원제의 농도와 환원 시간에 크게 영향을 받았다. An amphiphilic graft copolymer consisting of a poly(vinyl chloride) (PVC) backbone and poly(styrene sulfonic acid) (PSSA) side chains (PVC-g-PSSA) was synthesized via atom transfer radical polymerization (ATRP). This polymer electrolyte membrane was ion-exchanged to Ag ions by immersing in 10 wt% $AgNO_3$ aqueous solution and templated the growth of Ag nanoparticles by a reducing agent. The formation of Ag nanoparticles was confirmed using UV-visible spectroscopy and X-ray diffraction (XRD). Transmission electron microscopy (TEM) revealed that utilization of $NaBH_4$ was the most effective in the formation of Ag nanoparticles with 10~15 nm in size. The formation of Ag nanoparticles was also strongly affected by the concentration of reducing agent and reduction time.

Crosslinked Composite Polymer Electrolyte Membranes Based On Diblock Copolymer and Phosphotungstic Acid

김종학,고주환,박정태,서진아,김종화,조영충,Kim, Jong-Hak,Koh, Joo-Hwan,Park, Jung-Tae,Seo, Jin-Ah,Kim, Jong-Hwa,Jho, Young-Choong The Membrane Society of Korea 2008 멤브레인 Vol.18 No.2

Proton conductive hybrid nanocomposite polymer electrolyte membranes comprising polystyrene-5-poly (hydroxyethyl methacrylate) (PS-b-PHEMA), sulfosuccinic acid (SA) and phosphotungstic acid (PWA) were prepared by varying PWA concentrations. The PHEMA block was thermally crosslinked by SA via the esterification reaction between -OH of PHEMA and -COOH of SA. Upon the incorporation of PWA into the diblock copolymer, the symmetric stretching bands of the $SO_3^-$ group at $1187cm^{-1}$ shifted to a lower wavenumber at $1158cm^{-1}$, demonstrating that the PWA particles strongly interact with the sulfonic acid groups of SA. When the concentration of PWA was increased to 30wt%, the proton conductivity of the composite membrane at room temperature increased from 0.045 to 0.062 S/cm, presumably due to the intrinsic conductivity of the PWA particles and the enhanced acidity of the sulfonic acid in the membranes. The membrane containing 30wt% of PWA exhibited a proton conductivity of 0.126 S/cm at $100^{\circ}C$. Thermal stability of the composite membranes was also enhanced by introducing PWA nanoparticles. 폴리스티렌-블록-폴리히드록에틸 메타크릴레이트(PS-b-PHEMA), 술포석시닉산(SA), 인텅스텐산(PWA)으로 구성된 수소 이온 전도성 나노복합 고분자 전해질막을 제조하였다. 폴리히드록에틸 메타크릴레이트(PHEMA) 블록의 히드록실그룹(-OH)와 술포석시닉산(SA)의 -COOH 그룹과의 에스테르 반응에 의하여 전해질막을 가교시켰다. 폴리헤테로산(PWA)을 도입했을 때, $SO_3^-$ 그룹의 신축 밴드가 $1187cm^{-1}$에서 $1158cm^{-1}$로 낮아졌으며, 이는 PWA 입자가 전해질막의 술폰산 그룹과 상호작용함을 나타낸다. PWA 함량이 30wt%가 되었을 때, 상온 전도도는 0.045에서 0.062S/cm로 증가되었으며, 이는 PWA 입자의 고유 전도도 특성과 전해질막의 술폰산기의 산도가 증가했기 때문이다. 또한 30wt%를 함유한 복합 전해질막은 $100^{\circ}C$에서는 최대 0.126 S/cm의 수소 이온 전도도를 나타내었다 PWA가 첨가됨에 따라 복합 전해질막의 열적특성 또한 증가하였다.

Preparation of Poly(vinyl chloride)-graft-poly(styrene sulfonic acid) Composite Nanofiltration Membranes

김종학,박정태,고주환,노동규,서진아,Kim, Jong-Hak,Park, Jung-Tae,Koh, Joo-Hwan,Roh, Dong-Kyu,Seo, Jin-Ah The Membrane Society of Korea 2008 멤브레인 Vol.18 No.2

Nanofiltration membranes were prepared based on coating a sulfonated comb-like copolymer layer on top of a poly(vinylidene fluoride) (PVDF) support. The comb-like copolymer comprising poly(vinyl chloride) backbone and poly(styrene sulfonic acid) side chains, i.e. PVC-g-PSSA was synthesized by atom transfer radical polymerization (ATRP) using direct initiation of the secondary chlorines of PVC. The successful synthesis of graft copolymers were confirmed by nuclear magnetic resonance ($^1H$-NMR), FT-IR spectroscopy and wide angle X-ray scattering (WAXS). Composite nanofiltration membranes consisting PVC-g-PSSA as a top layer exhibited the increase of both rejections and solution flux with increasing PSSA concentration. This performance enhancement is presumably due to the increase of SO3H groups and membrane hydrophilicity. The rejections of composite membranes containing 71 wt% of PSSA were 88% for $Na_2SO_4$ and 33% for NaCl, and the solution flux were 26 and $34L/m^2h$, respectively, at 0.3 MPa pressure. 폴리비닐리덴플로라이드(PVDF) 지지체 위에 빗살모양의 술폰화된 공중합체를 코팅하여 나노 분리막을 제조하였다. 빗살모양의 공중합체는 원자전달 라디칼 중합법(ATRP)에 의해 제조하였으며, 폴리비닐클로라이드의 주사슬과 폴리스티렌 술폰산(PSSA)의 곁사슬로 구성되어 있다. 핵자기 공명법($^1H$-NMR), FT-IR분광학 그리고 WAXS 분석법에 의해 공중합체가 성공적으로 합성되었음을 확인하였다 PVC-g-PSSA로 구성된 복합 나노 분리막은 PSSA의 함량이 증가함에 따라 플럭스와 배제율 모두 증가하였다. 이러한 성능 향상은 분리막의 술폰산의 함량의 증가로써 설명할 수 있다. PSSA가 71wt%첨가된 나노 복합막의 배제율은 $Na_2SO_4$ 88%, NaCl 33%을 나타내었고, 플럭스는 $Na_2SO_4$ 26, NaCl $34L/m^2 h$을 각각 나타내었다.

Preparation of Anhydrous Crosslinked Graft Copolymer Electrolyte Membrane

노동규(Roh, Dong-Kyu),고주환(Koh, Joo-hwan),박정태(Park, Jung-tae),서진아(Seo, Jin-ah),김종학(Kim, Jong-hak) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.06

A comb-like copolymer consisting of a poly(vinylidene fluoride-co-chlorotrifluoro-ethylene) backbone and poly(hydroxy ethyl acrylate) side chains, i.e. P(VDF-co-CTFE)-g-PHEA, was synthesized through atom transfer radical polymerization (ATRP) using CTFE units as a macroinitiator. Successful synthesis and a microphase-separated structure of the copolymer were confirmed by proton nuclear magnetic resonance (1H-NMR), FT-IR spectroscopy, and transmission electron microscopy (TEM). This comb-like polymer was crosslinked with 4,5-imidazole dicarboxylic acid (IDA) via the esterification of the -OH groups of PHEA and the -COOH groups of IDA. Upon doping with phosphoric acid (H₃PO₄) to form imidazole-H₃PO₄ complexes, the proton conductivity of the membranes continuously increased with increasing H₃PO₄ content. A maximum proton conductivity of 0.015 S/cm was achieved at 120?C under anhydrous conditions. In addition, these P(VDF-co-CTFE)-g-PHEA/IDA/H₃PO₄ membranes exhibited good mechanical properties (765 MPa of Young's modulus), and high thermal stability up to 250?C, as determined by a universal testing machine (UTM) and thermal gravimetric analysis (TGA), respectively.

Design of Supramolecular Electrolytes for Solid State Dye-sensitized Solar Cells

고종관(Koh, Jong-Kwan),고주환(Koh, Joo-Hwan),서진아(Seo, Jin-Ah),김종학(Kim, Jong-Hak) 한국신재생에너지학회 2009 한국신재생에너지학회 학술대회논문집 Vol.2009 No.06

Solid-state dye-sensitized solar cells (DSSCs) have been constructed employing supramolecular electrolytes with multiple hydrogen bonding. A supramolecule was facilely synthesized by one-pot reaction between the amines of methyl isocytosine (MIC) and the epoxy groups of poly(ethylene glycol diglycidyl ether) (PEGDGE) to produce quadruple hydrogen bonding units. Hydrogen bonding interactions and dissolution behavior of salt in supramolecular electrolytes are investigated. The ionic conductivity of the supramolecular electrolytes with ionic liquid, i.e. 1-methyl-3-propylimidazolium iodide (MPII) reaches 8.5{times}10^{-5} S/cm at room temperature, which is higher than that with metal salt (KI). A worm-like morphology is observed in the FE-SEM micrographs of TiO₂ nanoporous layer, due to the connection of TiO₂ nanoparticles resulting from adequate coating by electrolytes. DSSCs employing the supramolecular electrolytes with MPII and KI exhibit an energy conversion efficiency of 2.5 % and 0.5 %, respectively, at 100 mW/cm², indicating the importance of the cation of salt. Solar cell performances were further improved up to 3.7 % upon introduction of poly(ethylene glycol dimethyl ether) (PEGDME) with 500 g/mol.

Synthesis and Characterization of Proton Conducting Graft Copolymer Membranes

노동규(Roh, Dong Kyu),고종관(Koh, Jong Kwan),서진아(Seo, Jin Ah),김종학(Kim, Jong Hak) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06

The grafting from technology to prepare the well-defined microphase-separated structure of polymer using atom transfer radical polymerization (ATRP) will be introduced in this presentation. Various amphiphilic comb copolymers were synthesized through this approach using poly (vinylidene fluoride) (PVDF), poly (vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-co-CTFE) and poly(vinyl chloride) (PVC) as a macroinitiator. Hydrophilic side chains such as poly (styrene sulfonic acid) (PSSA) or poly (sulfopropyl methacrylate) (PSPMA) were grafted from the mains chains using direct initiation of the chlorine atoms. The structure of mass transport channels has been controlled and fixed by crosslinking the hydrophobic domains, which also provides the greater mechanical properties of membranes. Successful synthesis and microphase-separated structure of the polymer were confirmed by ¹H NMR, FT-IR spectroscopy and TEM. The grafted/crosslinked membranes exhibited good mechanical properties (400 MPa of Young's modulus) and high thermal stability (up to 300?C), as determined by a universal testing machine (UTM) and TGA, respectively.