• 생약학회지
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• 제26권1호
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• pp.1-7
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• 1995

The bark of Ulmus parvifolia Jacq. (Ulmaceae) has been used for the treatment of gonorhea, edema, scabies and eczema marginatum. Previous investigations conducted with the heartwood and leaves have demonstrated it to contain sesquiterpenes as well as fat acids from the heartwood and flavonol glycosides from leaves. However, no phytochemical work has been done on the bark parts of this plant. Investigation of the phytochemical constituents in the barks of U. parvifolia has resulted in the isolation of sterols, sterol glucoside and a catechin glycoside, $(+)-catechin\;7-O-{\alpha}-{_L}-rhamnopyranoside$, all of which were isolated for the first time from this plant. Sterols were consisted of the three components, ${\beta}-sitosterol$, stigmasterol and campesterol in a ratio of 92.1:4.1:3.8, and sterol glucoside was identified as ${\beta}-sitosterol\;3-O-{\beta}-{_D}-glucoside$. The structure of the catechin $7-O-{\alpha}-{_L}-rhamnoside$ was established primarily by analysis of $^1H-and$ COSY-45 NMR, HMQC and HMBC and EI mass spectra of the heptaacetate. Especially, HMBC spectrum provides effective way for the determination of the point of attachment of the rhamnosyl group to catechin moiety.

• Macromolecular Research
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• 제11권1호
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• pp.47-52
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• 2003

The objective of this study was to develop a polymeric drug delivery system for camptothecin (CPT), capable of improving its therapeutic index and reducing its side effects. A monomeric conjugate, 3,6-endo-methylene-1,2,3,6-tetrahydrophthalimidoethanoylcamptothecin in (ETECPT) between CPT and 3,6-endo-methylene-1,2,3,6-tetrahydrophthalimidoethanoic acid was synthesized. Its homo-and copolymer with acrylic acid (AA) were prepared by photopolymerization using 2,2-dimethoxy-2-phenylacetophenone (DMP) as a photoinitiator. The monomer and its polymers were characterized by IR, $^1$H- and $^{13}$ C-NMR spectra. The ETECPT content in poly(ETECPT-co-AA) obtained by elemental analysis was 82 wt%. The number-average molecular weights of the polymers determined by gel permeation chromatography were as follows: M$_{n}$ = 11,400 for poly(ETECPT), M$_{n}$ = 17,900 for poly(ETECPT-co-AA). The $IC_{50}$/ values of ETECPT and its polymers against cancer cells were much larger than that of CPT. Our results from the in vivo antitumor activity indicated that all polymers show high antitumor activity than CPT at a dose of 100 mg/kg./kg.

• 공업화학
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• 제18권6호
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• pp.607-611
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• 2007

양이온성 천연고분자 물질로서 유전자와 효과적으로 복합체를 형성할 수 있는 저분자량 수용성 키토산(LMWSC)에 유전자 발현 효율을 높이기 위해 histidine을 컨쥬게이션 시킨 유전자 전달체를 제조하였다. 히스티딘-LMWSC의 제조는 무수프탈산으로 LMWSC의 아민기를 보호한 후 히스티딘과 결합한 다음 무수프탈산을 제거하는 반응으로 제조하였다. 제조한 유전자 전달체의 물리화학적 특성은 FT-IR과 NMR 스펙트럼을 통하여 확인하였고, 전기영동 결과로부터 본 실험에서 제조된 유전자 전달체와 DNA가 복합체를 형성하였다는 것을 알 수 있었다. 또한 유전자 전달체의 입자크기는 DLS를 이용하여 측정한 결과 히스티딘-LMWSC-DNA 복합체입자의 크기는 100~200 nm임을 확인하였다. 이로부터 히스티딘을 함유하는 LMWSC가 유전자 전달체로서 사용될 수 있음을 확인하였다.

• Food Science and Biotechnology
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• 제18권4호
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• pp.872-877
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• 2009

By-products of marine organisms including salmon, skate, flatfish, and yellow goosefish were investigated to search for new source of chondroitin sulfate (CS). Agarose gel electrophoresis with chondroitinase depolymerization showed that purified chondroitin sulfate did not contain any other glycosaminoglycans. 1H-nuclear magnetic resonance (NMR) spectra were acquired to confirm the structure and purity. The average molecular weight ranging from 22 to 64 kDa was determined by high performance size exclusion chromatography. Disaccharide compositions and purities were determined by strong anion exchange-high performance liquid chromatography (SAX-HPLC) after chondroitinase ABC depolymerization. SAX-HPLC data exhibited that the purity was from $81.7{\pm}1.3$ to $114.2{\pm}2.5%$ and the yield was from 1.3 to 12.5%. All analytical results indicate that salmon cartilage, skate cartilage, and yellow goosefish bone could be promising sources of CS to substitute shark cartilage CS in commercial neutraceuticals.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.129-129
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• 2010

The conjugated oligomers with rigid and fused-ring structures are of interest for the solution-processable organic thin film transistors (OTFTs) due to their well defined structure and high purity. In this study, alkyl substituted benzothiophene based oligomers were synthesized by a novel route, the key point of which is the acid-induced intermolecular cyclization reaction of aromatic methyl sulfoxides, and were confirmed by $^1H$-NMR and FT-IR studies. The obtained oligomers showed the good solubility in common organic solvents such as hexane, chloroform, and dimethylchloride at room-temperature, which is due to the introduced alkyl chain. The physical and optical properties of the oligomers were studied using differential scanning scalorimetry (DSC), cyclic-voltammetry (CV), UV-visible and PL spectra studies. Solution processed OTFT device based on synthesized oligomers show a high hole mobility of up to $0.01\;cm^2V^{-1}s^{-1}$, $I_{on}/I_{off}$ of $10^5$ and threshold voltage of -14V.

• Bulletin of the Korean Chemical Society
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• 제15권11호
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• pp.967-971
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• 1994

The stability constants, log K of the 1 : 1 complexation for IA ions, $Ag^+$, and $Tl^+$ with a series of podands having different aromatic end-groups (I-IV) have been determined conductometrically in methanol at 25.0 $^{\circ}$C. Exceptionally the equivalent conductivity, ${\lambda}_{eq}\;of\;Li^+\;and\;Na^+$ were increased by the addition of I, because the complexed ions are less mobile than solvated ions. The order of log K values for I was $Ag^+{\gg}Tl^+>K^+>Na^+>Rb^+>Cs6+>Li^+$. The log K sequence of the podands for the certain cations was I>II>III${\geq}$IV. And every podands except IV showed the maximum selectivity for $Ag^+$ among the cations. These results were discussed in terms of the aromatic end-group effects, such as hetero-donor atoms or conformational changes by ${\pi}-{\pi}$ stacking interactions. The detailed conformations of ${\pi}-{\pi}$ stacking were also discussed by the observations of upfield shifts of some aromatic protons upon complexation from $^1H$ NMR spectra.

• Advances in Energy Research
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• 제4권2호
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• pp.177-187
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• 2016

Ammonia borane $NH_3BH_3$ solubilized in organic solvent is a potential liquid-state chemical hydrogen storage material. In this study, metal acetylacetonates like $Fe(O_2C_5H_7)_3$, $Co(O_2C_5H_7)_2$, $Ni(O_2C_5H_7)_2$, $Pd(O_2C_5H_7)_2$, $Pt(O_2C_5H_7)_2$ and $Ru(O_2C_5H_7)_3$ are considered for assisting dehydrocoupling of ammonia borane in diglyme (0.135 M) at $50^{\circ}C$. The molar ratio between ammonia borane and metal acetylacetonate is fixed at 100. A protocol for the separation of the soluble and insoluble fractions present in the slurry is proposed; it consists in using acetonitrile to make the precipitation of metal-based compounds easier and to solubilize boron-based intermediates/products. The nature of the metal does not affect the dehydrocoupling mechanisms, the $^{11}B\{^1H\}$ NMR spectra showing the formation of the same reaction intermediates. The aforementioned metal acetylacetonates do mainly have effect on the kinetics of dehydrocoupling. Dehydrocoupling takes place heterogeneously and dehydrogenation of ammonia borane in these conditions leads to the formation of polyborazylene via intermediates like e.g., B-(cyclodiborazanyl) amine-borane and borazine. Our main results are reported and discussed herein.

• 대한화학회지
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• 제54권5호
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• pp.515-522
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• 2010

o-phenylene diamines, dehydroacetic acid (DHA) 및 p-chloro benzaldehyde에서 유도된 세자리 Schiff 염기 리간드인 4-hydroxy-3(1-{2-(benzylideneamino)-phenylimino}-ethyl)-6-methyl-2H-pyran-2-one (HL)의 Cu(II), Ni(II), Co(II), Mn(II) 및 Fe(III) 착물의 형성상수와 항미생물 활성과의 관계를 연구하였다.리간드와 착물은 원소분석, 전도도, 자기수자율, 열분석, X-선 회절, IR, $^1H$-NMR, UV-vis 및 질량 스펙트럼으로 특성조사를 하였다. 분석데이터로부터 착물들의 화학량론비가 1:2 (금속:리간드)임을 알았다. 금속 착물들의 몰 전도도 값은 이들의 비전해질 성질을 의미한다. X-선 회절 데이터에서 Ni(II) 착물은 단사정계 그리고 Cu(II) 및 Co(II) 착물은 삼사정계 결정계임을 규명하였다. IR 스펙트럼 데이터로부터 리간드는 중심금속에 대해 ONN 주개원자 배열의 세자리 리간드로 행동함을 알았다. 열적 행동 (TG/DTA)과 Coats-Redfern 법에 의해 계산한 반응속도 파라메터는 착물형성 과정에서 좀 더 질서 있는 활성화 상태를 제안하고 있다. 착물의 양성자화 상수를 THF:물 (60:40) 용액, $25^{\circ}C$ 및 이온세기 ${\mu}=0.1\;M$ ($NaClO_4$)에서 전위차법으로 측정하였다. Staphylococcus aureu 및 Escherichia coli.에 대한 항박테리아 활성을 시험관에서 조사하였다. 또한 Aspergillus Niger 및 Trichoderma에 대한 항세균 활성도 조사하였다. 금속 이온 및 착물의 안정도가 항미생물학적 활성에 미치는 영향을 고찰하였다.

• 임산에너지
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• 제17권1호
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• pp.56-70
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• 1998

This study was carried out to investigate the structural characteristics of kraft lignin and the wood degrading characteristics, the productivity of ligninolytic enzymes and the enzymatic degradation of kraft lignin by white-rot fungi. To purify kraft lignin, precipitation of kraft pulping black liquors of pitch pine meal was done by titration with lN $H_{2}SO_{4}$ reaching to pH 2, and isolation of the precipitates done by centrifugation. The isolated precipitates from pitch pine were redissloved in lN NaOH, reprecipitated by titration with lN $H_{2}SO_{4}$, washed with deionized water, and kept ofr analysis after freeze drying. Fractionation of the precipitates in solution by successive extraction with $CH_{2}Cl_{2}$ and MeOH, and the fractionates were named SwKL, SwKL I, SwKL II, and SwKL III for pitch pine kraft lignin. The more molecular weights of kraft lignin increased, the less phenolic hydroxyl groups and the more aliphatic hydroxyl groups. Because as the molecular weights increased, the ratio of etherified guaiayl/syringyl(G/S ratio) and the percentage were increased. The spectra obtained by 13C NMR and FTIR assigned by comparing the chemical shifts of various signals with shifts of signals from autherized ones reported. The optimal growth temperature and pH of white-rot fungi in medium were $28^{\circ}C$ and 4.5-5.0, respectively. Especially, in temperature and pH range, and mycelial growth, the best white-rot fungus selected was Phanerochaete chrysosporium for biodegradation. For the degradation pathways, the ligninolytic fungus jcultivated with stationary culture using medium of 1% kraft lignin as a substrate for 3 weeks at $28^{\circ}C$. The weight loss of pitch pine kraft lignin was 15.8%. The degraded products extracted successively methoanol, 90% dioxane and diethyl ether. The ether solubles were analyzed by HPLC. Kraft lignin degradation was initiated in $\beta$-O-4 bonds of lignin by the laccase from Phanerochaete chrysosporium and the degraded compounds were produced from the cleavage of $C\alpha$-$C\beta$ linkages at the side chains by oxidation process. After $C\alpha$-$C\beta$ cleavage, $C\alpha$-Carbon was oxidized and changed into aldehyde and acidic compounds such as syringic acid, syringic aldehyde and vanilline. And the other compound as quinonemethide, coumarin, was analyzed. The structural characteristics of kraft lignin were composed of guaiacyl group substituted functional OHs, methoxyl, and carbonyl at C-3, -4, and -5 and these groups were combinated with $\alpha$ aryl ether, $\beta$ aryl ether and biphenyl. Kraft lignin degradation pathways by Phanerochaete chrysosporium were initially accomplished cleavage of $C\alpha$-$C\beta$ linkages and $C\alpha$ oxidation at the propyl side chains and finally cleavage of aromatic ring and oxidation of OHs.

• 대한화학회지
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• 제58권2호
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• pp.169-178
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• 2014

A new series of metal complexes of V(IV), Pd(II), Pt(IV), Ce(IV) and U(VI) with 3-[(3-chlorophenyl)-hydrazono]-pentane-2,4-dione (Cphpd) were synthesized and characterized by elemental analysis, molar conductivity, magnetic moment measurements, UV-vis, FT-IR and $^1H$ NMR as well as TG-DTG techniques. The data indicated that the Cphpd acts as a bidentate ligand through the hydrazono nitrogen and one keto oxygen. The kinetic parameters have been evaluated by using Coats Redfern (CR) and Horowitz-Metzeger (HM) methods. The thermodynamic data reflected the thermal stability for all complexes. The calculated bond length and the bond stretching force constant, F(U=O), values for $UO_2$ bond are $0.775{\AA}$ and $286.95Nm^{-1}$. The bond lengths, bond angles, dipole moment and the lowest energy model structure of the complexes have been determined with DFT calculations. The antimicrobial activity of the synthesized ligand and its complexes were screened.