• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.993-999
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• 2011

The photoreactive prepolymers with multifunctional cinnamate and bisphenol Atype cinnamate groups that could perform photodimerization without photoinitiators were synthesized by the reaction of t-cinnamic acids (CAs) and epoxy resins. Their photocure reaction rates and the extent of reaction conversion were measured with Fourier transform infrared spectroscopy, and these increased with the intensity of UVirradiation. The experimental data of these reaction rates showed the characteristics of nth-order kinetics reaction, and all kinetic constants of each photoreactive polymer with this equation were summarized. Although the GTR-1800-HCA and KWG1-EP-HCA with hydroxyl group substituted cinnamate showed lower reaction conversion rates and rate constant than GTR-1800-CA and KWG1-EP-CAwith an unsubstituted cinnamate group, GTR-1800-MCAand KWG1-EP-MCAwith methoxy group substituted cinnamate showed similar and higher reaction conversion rates than the former, respectively. These results were explained in terms of segmental mobility for photopolymerization by molecular interactions.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.863-867
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• 2013

A series of azo disperse dyes having dicyanovinyl groups was synthesized by the Knoevenagel condensation with malononitrile from carbonyl substituted phenylazo disperse dyes which were prepared by conventional diazo coupling reaction of aniline derivatives as diazo components. A variety of coupling components such as anilines, an indole and a pyridone were used. The azo disperse dyes were evaluated for their spectral properties and dyeing assessment on the polyester fabrics. The azo disperse dyes containing dicyanovinyl groups showed bathochromic shifts and darker colors due to increased electron withdrawing strength in their azo components and extended conjugation by dicyanovinyl groups than their parent carbonyl substituted azo dyes. The dyes containing 2-acetylamino-5-methoxy substituent in the coupling component exhibited higher wavelength of maximum absorbance (${\lambda}_{max}$) and significant negative solvatochromism than those of other dyes due to intramolecular hydrogen bonding.

• 대한예방한의학회지
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• 제11권1호
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• pp.1-8
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• 2007

Curcumin and its analogues(Tetrahydrocurcumin THC, demethoxycurcumin ; BDMC and dimethoxycurcumin DiMC) were compared for their ability to inhibit the growth of human leukemia HL-60 cells. The growth of HL-60 cells was inhibited by curcumin, DeMC and DiMC, but not by THC lacking ${\alpha},{\beta}-unsaturated$ carbonyl groups thus suggesting that ${\alpha},{\beta}-unsaturated$ carbonyl groups are crucial for antiproliferative activity. The order of antiproliferative activity was DiMC, curcumin and BDMC indicating that the number of methoxy groups on the aromatic rings of the active compounds plays an important role in enhancing anti-proliferating activity. In comparison with cellular uptake of the active compounds, uptake capacity was found to be highest with DiMC, followed by curcumin and BDMC. Therefore, it is most likely that the differential antiproliferative activities of DiMC, curcumin and BDMC are associated with their capacities of cellular uptake resulting in building up of enough concentration inside the cells.

• Macromolecular Research
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• 제13권5호
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• pp.373-384
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• 2005

Novel pH-sensitive moieties containing an s-triazine ring were synthesized with sulfonamide and secondary amino groups. The synthesized pH-sensitive moieties were used for the synthesis of a pH-sensitive amphiphilic ABA triblock copolymer. The pH-sensitive triblock copolymer was composed of diblock copolymers, methoxy poly(ethylene glycol)-poly ($\varepsilon$-caprolactone-co-D,L-lactide) (MPEG-PCLA), and pH-sensitive moiety. These copolymers could be dissolved molecularly in both acidic and basic aqueous media at room temperature due to secondary amino and sulfonamide groups. The synthesized s-triazine rings containing pH-sensitive compounds were characterized by ${^1}H-NMR,\;{^13}C-NMR$, and LC/MSD spectral data. The synthesized diblock and triblock copolymers were also characterized by ${^1}H-NMR$ and GPC analyses. The critical micelle concentrations at various pH conditions were determined by fluorescence technique using pyrene as a probe. Furthermore, the micellization and demicellization study of the triblock copolymer was done with pH-sensitive groups. The sensitivity towards pH change was further established by acid-base titration.

• Bulletin of the Korean Chemical Society
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• 제23권2호
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• pp.330-336
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• 2002

A quantum-chemical investigation on the conformations and electronic properties of bis[2-{2-methoxy-4,6-di(t-butyl)phenyl}ethenyl]benzenes (MBPBs) as building block for ${\pi}$-conjugate polymer are performed in order to display the effects of t-butyl and methoxy group substitution and of kink(ortho and meta) linkage. The conjugation length of the polymers can be controlled by substituents and kink linkages of backbone. Structures for the molecules, o-, m-, and p-MBPBs as well as unsubstituted o-, m-, and p-DSBs were fully optimized by using semiempirical AM1, PM3 methods, and ab initio HF method with 3-21G(d) basis set. The potential energy curves with respect to the change of single torsion angle are obtained by using semiempirical methods and ab initio HF/3-21G(d) basis set. The curves are similar shape in the molecules with respect to the position of vinylene groups. It is shown that the conformations of the molecules are compromised between the steric repulsion interaction and the degree of the conjugation. Electronic properties of the molecules were obtained by applying the optimized structures and geometries to the ZINDO/S method. ZINDO/S analysis performed on the geometries obtained by AM1 method and HF/3-21G(d) level is reported. The absorption wavelength on the geometries obtained by AM1 method is much longer than that by HF/3-21G(d) level. The absorption wavelength of MBPBs are red shifted with comparison to that of corresponding DSBs in the same torsion angle because of electron donating substituents. The absorption wavelength of isomers with kink(orth and meta) linkage is shorter than that of para linkage.

• 농약과학회지
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• 제3권1호
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• pp.96-101
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• 1999

새로운 합성방법을 개발하여 pyrazolate 제초제의 곁가지를 변화시킨 새로운 구조의 3-trifluoro-methylpyrazole 유도체들과 4-benzenecarbinolpyrazole 유도체 등을 합성하여 전작과 답작상태에서 제초활성 시험을 하였다. 밭조건에서는 발아전처리의 경우 4 kg/ha의 약량에서도 제초효과를 나타내지 않았으며 발아후처리에서는 제초효과가 있었으나 미약하였다. 답작상태에서는 4 kg/ha의 약량에서 제초효과가 있었으며 특히 4-benzoylpyrazole의 benzene의 4위치에 electron-donating group인 methoxy가 치환된 화합물의 경우 활성과 선택성이 매우 좋았다. 그러나, methoxy가 두 개 이상 치환되거나 다른 electron-donating group인 sulfide기가 치환된 화합물들의 제초활성은 약하였다.

• Archives of Pharmacal Research
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• 제16권3호
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• pp.219-226
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• 1993

For the analysis of structure relationship of ar-turmerone analogues, the compounds containing the various substituents on the phenyl ring and 1(or 2)-naphthyl group in the place of phenyl of ar-turmerone were prepared and tested their cytotoxicity against HL-60, K-562, and L1210 leukemia cells in vitro. The substituents at para position are methoxy, phenoxy, methyl, trifluoromethyl, fluoro, and chloro. At meta position methoxy, methyl, trifluoromethyl, or chloro groups at ortho position mathoxy or chloro group were introduced. Against HL-60 and K-562 cells, $ED_{50}$ values of the analogues are ranged from 0.8 to $30.0\;\mu{g/ml}$. Againste L1210 cell, these are located more than $20.0\;\mu{g/ml}$. However, 5-carbone-thoxy-2-methyl-6(1-naphthyl)-2-octen-4-one (5n)possesses $ED_{50}$ valuses 0.8, 2.1, $6.5\;\mu{g/ml}$ against HL-60, L1210 cells, respectively. The electronic nature of the substituents on phenyl ring of ar-tumerone dose not affect the biological activity. Therefore the flat structure of aromatic potion of ar-tumerone analogues is the more important factor for their activity rather than its electronic nature. The potentiation of the cytotoxicity with the enlargement of aromatic ring region also supports the importance of the plane structure of this area. The restriction of the single bond rotation between C-6 and aromatic ring through the introduction of substituents at the ortho position of phenyl ring and the increment of size of alkyl group at C-6 position enhances the activity. Therefore the effective conformation should by the one having the orthogonal arrangement between the aromatic ring and the side chain.

• Applied Biological Chemistry
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• 제47권4호
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• pp.414-421
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• 2004

새로운 5-methyl-3-phenylisoxazolin-5-yl)methoxy-2-chloro-4-fluorobenzenes 유도체들의 구조 변화에 의한 벼(Orysa sativa L.)와 논피 (Echinochloa crus-galli) 뿌리와 줄기 부위의 protox 저해활성에 대한 3차원적 구조-활성관계(3D-QSAR)에 근거하여(성낙도, 등 (2004) 한국응용생명화학회지 47(3), 351-356) 비교분자 유사성 지수분석(CoMSIA) 방법으로 연구하였다. 두 초종의 부위별 protox 저해활성에 관한 CoMSIA 모델들은 수소결합 주게장이 제외된 입체장, 정전기장, 소수성장, 수소결합 받게장 등으로 조합된 CoMSIA장과 부가적 설명 인자로서 LUMO 분자 궤도장, 몰라 굴절을(MR) 및 쌍극자 능율(DM) 등이 추가된 조건에서 유도되었다. 방제 대상인 논피에 대한 모델이 벼에 대한 모델보다 양호하였으며 논피에 대한 모델은 cross-validated $r^2\;_{cv.}$값$(q^2=0.871{\sim}0.913)$과 non cross-validated $r^2\;_{ncv.}$값$(0.936{\sim}0.920)$ 그리고 PRESS 값$(0.255{\sim}0.273)$에 근거하여 매우 좋은 예측성을 나타내었다. 그리고 protox 저해 활성은 분자의 입체장$(5.4{\sim}15.7%)$ 및 소수성장$(68.0{\sim}84.3%)$과 높은 상관성을 보였다. 이같은 CoMSIA 분석결과, 논피에 대한 선택적인 protox 저해활성은 C-phenyl 고리상 ortho-위치가 steric bulky 할수록 클 것으로 예상되었다.

• Bulletin of the Korean Chemical Society
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• 제24권7호
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• pp.901-905
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• 2003

The lower critical solution temperature (LCST) of thermosensitive poly(organophosphazenes) with methoxypoly(ethylene glycol) (MPEG) and amino acid esters as side groups was studied as a function of saccharide concentration in aqueous solutions of mono-, di-, and polysaccharides. Most of the saccharides decreased the LCST of the polymers, and the LCST decrease was more prominently observed by saccharides containing a galactose ring, such as D-galactose, D-galactosamine and D-lactose, and also the polysacccharide, 1-6-linked D-dextran effectively decreased the LCST of the polymers. Such an effect was discussed in terms of intramolecular hydrogen bonding of saccharides in polymer aqueous solution. The saccharide effect was found to be almost independent on the kinds of the amino acid esters and MPEG length of the polymers. Such a result implies that the polymer-saccharide interaction in aqueous solution is clearly influenced by the structure of sacchardes rather than by that of the polymers. The acid saccharides such as D-glucuronic and D-lactobionic acid increased the LCST, which seems to be due to their pH effect.

• Journal of Microbiology and Biotechnology
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• 제25권8호
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• pp.1361-1370
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• 2015

A blue laccase was purified from a white rot fungus of Trametes trogii, which was a monomeric protein of 64 kDa as determined by SDS-PAGE. The enzyme acted optimally at a pH of 2.2 to 4.5 and a temperature of 70℃ and showed high thermal stability, with a half-life of 1.6 h at 60℃. A broad range of substrates, including the non-phenolic azo dye methyl red, was oxidized by the laccase, and the laccase exhibited high affinity towards ABTS and syringaldazine. Moreover, the laccase was fairly metal-tolerant. A high-molecular-weight kraft lignin was effectively polymerized by the laccase, with a maximum of 6.4-fold increase in weight-average molecular weight, as demonstrated by gel permeation chromatography. Notable structural changes in the polymerized lignin were detected by Fourier transform infrared spectroscopy and ¹H NMR spectroscopy. This revealed an increase in condensed structures as well as carbonyl and aliphatic hydroxyl groups. Simultaneously, phenolic hydroxyl and methoxy groups decreased. These results suggested the potential use of the laccase in lignin modification.