• Bulletin of the Korean Chemical Society
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• v.35 no.10
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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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• v.48 no.2
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• pp.148-155
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• 2013

The crosslinking density of polymer can be quantitatively calculated by the Flory-Rehner equation using the swelling experimental data and the lattice constant ${\beta}_1$ of interaction parameter (${\chi}$) in this equation should be chosen have used cautiously. This ${\beta}_1$ is the experimental data by rule of thumb, and researchers have used little different values respectively. Generally, the average molecular weight between crosslink points $M_c$ in the Flory-Rehner equation and the Mooney-Rivlin equation have the same value, and ${\beta}_1$ can be calculated when the $M_c$ in the Flory-Rehner equation is given. Therefore, in this research, firstly we calculated the $M_c$ using the selected ${\beta}_1$ (=0.34) and the swelling experimental data of 1,2,3-triazole polymer from the Flory-Rehner equation, secondly the $M_c$ from the Mooney-Rivlin equation is calculated by the tensile experimental data, and finally two $M_c$ were compared. As a result, two $M_c$ values were almost the same, and it was proved that the ${\beta}_1$ (=0.34) was selected properly.

• Toxicological Research
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• v.13 no.4
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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.

• YAKHAK HOEJI
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• v.49 no.1
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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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• v.26 no.5
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• pp.833-836
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• 2005

• Bulletin of the Korean Chemical Society
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• v.29 no.4
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• pp.723-724
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• 2008

• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1243-1246
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• 2013

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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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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• v.34 no.8
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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.

• Proceedings of the PSK Conference
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• 2003.10b
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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)