• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.3001-3004
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• 2014

A series of hydroxyl-derivatized quaternized polymers were successfully synthesized by atom transfer radical polymerization (ATRP) and Cu(I)-catalyzed 1,3-dipolar cycloaddition of azide and alkynes (click chemistry), followed by quaternization reactions. ATRP was employed to synthesize poly(2-hydroxyethyl methacrylate) (PHEMA), followed by introduction of alkyne groups using pentynoic acid, leading to HEMA-Alkyne. 2-Azido-1-ethanol and 3-azido-1-propanol were combined with the HEMA-Alkyne backbone via click reaction, resulting in triazole-ring containing hydroxyl-derivatized polymers. Quaternization reactions with methyl iodide were conducted on the triazole ring of each polymer. Molecular weight, molecular weight distribution, and the degree of quaternization (DQ) were determined by gel permeation chromatography (GPC) and $^1H$ NMR spectroscopy. The average molecular weight ($M_n$) of the resulting polymers ranged from $5.9{\times}10^4$ to $1.05{\times}10^5g/mol$ depending on the molecular architecture. The molecular weight distribution was low ($M_w/M_n$ = 1.26-1.38). The transmission spectra of the 0.1 wt % aqueous solutions of the resulting quaternized polymers at 650 nm were measured as a function of temperature. Results showed that the upper critical solution temperature (UCST) could be finely controlled by the level of DQ.

• Elastomers and Composites
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• 제48권2호
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• pp.148-155
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• 2013

폴리머의 가교밀도는 팽윤 실험 데이터를 이용한 Flory-Rehner 식에 의하여 정량적으로 계산할 수 있는데, Flory-Rehner 식에서 상호계수 (${\chi}$) 항에 있는 lattice constant ${\beta}_1$ 값은 주의해서 선정되어야 한다. 이 ${\beta}_1$ 값은 경험에 의한 실험값으로 연구자에 따라 조금씩 다른 값이 선택되어 사용되고 있다. 일반적으로 Mooney-Rivlin 식에서 가교점 사이의 평균 분자량 $M_c$ 값은 Flory-Rehner 식에서의 $M_c$ 값과 동일한 의미를 가지며 Mooney-Rivlin 식으로부터 $M_c$ 값을 구하면 Flory-Rehner 식에서 ${\beta}_1$ 값을 구할 수 있다. 따라서 본 연구에서는 먼저 Flory-Rehner 식의 상호계수 (${\chi}$) 항의 ${\beta}_1$ (=0.34) 과 1,2,3-트리아졸 폴리머의 팽윤 실험 데이터를 적용하여 $M_c$ 값을 계산하고, 두 번째로 인장 실험 데이터를 이용한 Mooney-Rivlin 식을 이용하여 $M_c$ 값을 계산 후 비교하였다. 결과적으로 두 개의 $M_c$ 값이 거의 유사하여 Flory-Rehner 식의 상호계수 (${\chi}$) 를 위해 선정한 ${\beta}_1$ (=0.34) 값이 적절함을 증명하였다.

• Toxicological Research
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• 제13권4호
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• pp.393-400
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• 1997

The effects of superoxide dismutase(SOD) and catalase on the toxicity of paraquat(PQ) were studied using diethyldithiocarbamate(DDC), 3-amino-1,2,4-triazole(AT) which are inhibitors of Cu, Zn-SOD and catalase in rats. Sprague Dawley rats were divide into 6 groups: control, DDC, PQ, AT, DDC+PQ, and AT+PQ group. The PQ (50 mg/kg body weight(BW); about half dose of $LD_{50}$) was administered with orally, otherwise AT(1.0g/kg BW) and DDC(1.0g/kg BW) were administered by intrperitoneal(iP) injection. The survival rate of rats in PQ+AT group was significantly decreased compared with PQ group while the difference of survival rate between DDC group and DDC+PQ group was not significant. The SOD activity after administration of DDC was decreased in liver, lung and kidney, but catalase activity was not changed. The catalase activity in liver, lung and kidney of AT treated rats was decreased, while SOD activity was not changed in this group. The effects of DDC and AT to the PQ toxicity was also observed in primary cultured rat Skin fibroblasts. The viable cells that was measured with MTT method, was decreased in AT+PQ treated group compared to PQ treated group, but the difference of cell viability between DDC treat group and DDC+PQ treated group was not observed. This result, AT potentlate PQ toxicity while DDC were not affect, suggested that the decreased catalase activity lead to elevation of hydrogen peroxide levels and PQ toxicity may be correlate with the hydrogen peroxide rather than the superoxides.

• 약학회지
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• 제49권1호
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• pp.51-55
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• 2005

In vitro ${\beta}$-lactamase inhibitory activity of 6-triazole exomethylenepenam compounds (1, 2, 3, 4, 5 and 6) was compared with clavulanic acid, sulbactam and tazobactam. The inhibitory activity of 3, 4 and 5 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type IV enzymes. And, inhibitory activity of 3 and 4 was stronger than those of sulbactam, clavulanic acid and tazobactam against Type III enzymes. The in vitro antimicrobial activity of 3, 4 and 5 combined with ampicillin was better than those with sulbactam and with cefoperazone was compared with the sulbactam against ${\beta}$-lactamase producing 27 strains. The synergistic activity of (Z)-form compounds (3 and 5) was better than that of (E)-form compound (4) and sulfone compound (5) was better than sulfide compound (3).

• Bulletin of the Korean Chemical Society
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• 제26권5호
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• pp.833-836
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• 2005

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.723-724
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• 2008

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1243-1246
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• 2013

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1605-1612
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• 2014

Copper(I)-catalyzed Huisgen cycloaddition of terminal alkynes with unmasked azidoamines derived from amino acids is described. The reported strategy provides a new entry to highly hindered ${\beta}$-amino 1,2,3-triazole derivatives bearing a gem-diaryl group, which are potentially valuable entities as molecular catalysts for asymmetric transformations.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2297-2304
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• 2013

A series of novel benzimidazole derivatives bearing a heterocyclic ring as oxadiazole (21-32), thiadiazole (33-34), triazole (35-36) were synthesized and evaluated for their activities against Coxsackie virus B3 and B6 in Vero cells. Compounds 21-26, 31-36 with moieties of 2'-pyridyl, 3'-pyridyl and 4'-pyridyl at the 2-position and oxadiazoles, thiadiazole, or triazole substituent at the 4- or 5-position generally displayed activities against CVB3 and CVB6. Especially compound 24 ($IC_{50}=1.08{\mu}g/mL$, SI = 61.7 against CVB3) was the promising candidate as lead compound for anti-enteroviral drug. It was observed in the incorporation of heterocyclic rings in benzimidazole at the 5-position could enhance their biological activities.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.181.2-181.2
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• 2003

Inosine monophosphate dehydrogenase(IMPDH) catalyzes the $NAD^+$-dependent oxidation of IMP to XMP, the rate limiting step in the de novo biosynthesis of guanine nucleotide. Its critical role at the metabolic branch point in purine nucleotide biosynthesis makes it a useful target in the development of drugs for antiviral and anticancer chemotherapy and in immunosupressant area. Several compound with antiviral activity have been found to be inhibitors of IMPDH. For example, ribavirin, a competitive inhibitor of IMPDH, has broad spectrum antiviral activities against DNA and RNA viruses. (omitted)