• YAKHAK HOEJI
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• v.34 no.2
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• pp.126-132
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• 1990

To enhance the activity of ibuprofen, amides of ibuprofen, 1-piperazinyl-2-(4-isobutylphenyl)propionamide(Ibu-P.A.) and 1-(4-methylpiperazinyl)-2-(4-isobutylphenyl)propionamide (Ibu-M.P.), were synthesized and the pharmaceutical properties and the pharmacological activities of the amides were studied. The lipid:water partition coefficients and pKa values were examined in vitro, and the antiinflammatory effect, analgesic effects, acute toxicity, and intestinal absorption were studied for the amides and compared with ibuprofen in vivo. The results are summarized as belows; 1) The lipid:water partition coefficients of Ibu-M.P. were higher than those of ibuprofen. 2) The calculated pKa values of ibuprofen and Ibu-M.P. were 5.49 and 8.66, respectively. 3) The antiinflammatory effects of ibuprofen, Ibu-P.A., and Ibu-M.P. were same intensity, but the duration of the effects of Ibu-P.A. and Ibu-M.P. were longer than that of ibuprofen. 4) The analgesic effect of Ibu-M.P. was more potent than those of ibuprofen and Ibu-P.A. in the acetic acid-induced writhing test. 5) The $LD_{50}$ was 495 mg/kg for ibuprofen, 187 mg/kg for Ibu-M.P., and over 1250 mg/kg for Ibu-P.A.. 6) The absorption rate constants(k) and half-life($t_{1/2}$) were 0.74($hr^{-1}$) and 0.94(hr) for ibuprofen, and 0.72 ($hr^{-1}$) and 0.96 (hr) respectively for Ibu-M.P..

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1096-1104
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• 1996

In order to synthesize a new antibacterial and antitumor agents, we have prepared new analogues pteroic acid(13a, 13b), which means C-9 position of pteroic acid has been replaced by norfloxacin(8) or ciprofloxacin(9) and amino group of C-2 position by $CH_3$. These derivatives were synthesized coupling at N-4 piperazine of norfloxacin and ciprofloxacin with 2-amino-3-cyano-5-chloromethylpyrazine(20) provided 1-alkyl(ethyl, cyclopropyl)-6-fluoro-1,4-dihydro-4-oxo-7-[[4-N-(2-amino-3-cyanopyrazin-5-yl)methyl]piperazin-1-yl]-3-quinoline-carboxylic acid(12a, 12b). It was then cyclized with acetamidine. HCI to obtain new analogues of C-2 desaminomethylpteroic acid(13a, 13b) in yield of 76.2% and 82.8 % respectively. These compounds were tested in vitro on antibacterial activity against Gram-positive and Gram-negative bacteria including Pseudomonas aeruginosa ATCC9027. In general, these synthesized compounds(13a, 13b) showed less potent activities than those of norfloxacin.

• YAKHAK HOEJI
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• v.33 no.5
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• pp.290-295
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• 1989

2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3-carboxylic acid methyl ester (1) was formylated to 2,6-dimethy-4-(3'-nitrophenyl)-5-formyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (2) in 76% yield. At the elevated temperature, 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-monomethyl ester (3) was also converted into compound 2 in 46% yield. The compound 2 was reduced to 2,6-dimethyl-4-(3'-nitrophenyl)-5-hydroxymethyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (4) in 91% yield. Compound 2 was reacted with triethyl phosphonoacetate to give 2,6-dimethyl-4-(3'-nitrophenyl)-5-(2-ethoxycarbonyl ethenyl)-1,4-dihydropyridine-3-carboxylic acid methyl ester (5) in 50% yield. Reaction between compound 2 and amines (methyl amine, ethylamine, methoxylamine, hydroxyl amine, phenyl hydrazine and 1-amino-4-methyl piperazine) gave six schiff bases 7a, 7b, 7c, 7e, 7f in 81%, 91%, 82%, 81%, 50% and 84% yield, respectively.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.251-262
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• 2011

Human ether-a-go-go related gene (hERG) potassium channel blockade, an undesirable side effect which might cause sudden cardiac death, is one of the major concerns facing the pharmaceutical industry. The purpose of this study is to develop an in silico QSAR model which uncovers the structural parameters of T-type calcium channel blockers to reduce hERG blockade. Comparative molecular similarity indices analysis (CoMSIA) was conducted on a series of piperazine and benzimidazole derivatives bearing methyl 5-(ethyl(methyl)amino)-2-isopropyl-2-phenylpentanoate moieties, which was synthesized by our group. Three different alignment methods were applied to obtain a reliable model: ligand based alignment, pharmacophore based alignment, and receptor guided alignment. The CoMSIA model with receptor guided alignment yielded the best results : $r^2$ = 0.955, $q^2$ = 0.781, $r^2_{pred}$ = 0.758. The generated CoMSIA contour maps using electrostatic, hydrophobic, H-bond donor, and acceptor fields explain well the structural requirements for hERG nonblockers and also correlate with the lipophilic potential map of the hERG channel pore.