• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.974-975
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• 2006

• YAKHAK HOEJI
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• v.35 no.6
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• pp.515-521
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• 1991

A number of 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-substitutedcarbamyl-1-piperazinyl) quinoline [or 1,8-naphthyridine]-3-carboxylic acid and their pivaloyloxymethyl esters were prepared. The compounds synthesized were evaluated for antibacterial activity in vitro against Escherichia coli, Bacillus subtilis, Proteus vulgaris, Klebsiella pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa. Among those 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methylcarbamyl-1-piperazinyl) quinoline-3-carboxylic acid [1] and 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methylcarbamyl-1-piperazinyl)1,8-naphthyridine-3-carboxylic acid [6] showed the most potent in vitro antibacterial activity.

• YAKHAK HOEJI
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• v.35 no.5
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• pp.353-359
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• 1991

Treatment of 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(l-piperazinyl)-I, 8- naphthyridine-3-ca rboxylic acid (Enoxacin) with alkyl(or aryl) isothiocyanates which obtained from alkyl(or aryl) amines afforded six 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-alkylthiocarbamylpiperazinyl)-1, 8- naphthyridine-3-carboxylic acids and five 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(l-arylthiocarbamyl piperazinyl)-1, 8-naphthyridine-3-carboxylic acids. The compounds synthesized were evaluated for their antimicrobial activities, in vitro, against Escherichia coli 6-PE-4, Bacillus subtilis 74-51, Proteus vulgaris 78645, Klebsiella pneumoniae JYA-78314, Staphylococcus aureus 79110 and Pseudomonas aeruginosa 8765-1 P$_{2}$.

• YAKHAK HOEJI
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• v.31 no.5
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• pp.338-342
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• 1987

8-tert-Butyl-6,7-dihydro-5-methyl-8H-pyrrolo [3,2-e]-s-triazolo [1,5-a] pyrimidine (Bumepidil), one of the s-triazolo [1,5-a] pyrimidine derivatives, has been recently found to be the most promising potential coronary vasodilator and antihypertensive agent. In this report, a new synthetic approach for Bumepidil, via direct N-amination of amino pyrimidine intermediate, was studied and found to be useful method. The novel synthetic method comprise the following steps, acylation of $\gamma$-butyrolactone, condensation with guanidine, direct N-amination, cyclization, chlorination, and finally cyclization using tert-butyl amine.

• YAKHAK HOEJI
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• v.40 no.6
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• pp.697-704
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• 1996

Quinolone derivatives, SJ5b (ethyl 5,12-dihydro-5-dihydro-5-oxobenzoxazolo[3,2-a]quinoline-6-carboxylate) and SQ7b (3-fluoro-2-(4-methylpiperazin-1-yl)-5.12-dihydro-5-oxobenzoxa zolo[3,2-a]quinoloine carboxylic acid) showed in vitro cytotoxicities against various tumor cell lines. SJ5b and SQ7b completely inhibited the DNA relaxation activities of human placental topoisomerase II at the concentration of 15.63 and 1.95 ${\mu}$g/ml, respectively. However, unlike etoposide which stabilize the topoisomerase II-DNA complex, SQ7b did not cause topoisomerase II-mediated DNA cleavage and SJ5b weakly stabilized the topoisomerase II-DNA cleavable complex. Through both experiments. DNA relaxation assay by the increment of topoisomerase II concentration and DNA unwinding assay, it was shown that SJ5b and SQ7b did not interact with topoisomerase II itself but bound to DNA. Therefore, it was concluded that DNA binding of SJ5b and SQ7b caused the inhibition of topoisomerase II related to DNA relaxation but no or very weak stabilization of topoisomerase II-DNA cleavable complex. In addition, SJ5b and SQ7b prevented whole cell nucleic acid syntheses in HL60 cells.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1080-1085
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• 2006

A series of 8-alkoxy-4,5-dihydro-[1,2,4]triazole[4,3-a]quinoline-1-one derivatives were synthesized using 7-hydroxy-3,4-dihydro-2(1H)-quinolone as the starting material. Their anticonvulsant activities were evaluated by the maximal electroshock test (MES) and the subcutaneous pentylenetetrazole test (sc-PTZ), and their neurotoxicities were measured by the rotarod neurotoxicity test (Tox). The tests demonstrated that 8-hexyloxy-4,5-dihydro-[1.2.4]triazole[4.3-a]quinoline-1-one (4e) and 8-heptyloxy-4,5-dihydro-[1,2,4]triazole[4, 3-a]quinoline-1-one (4f) were the most potent anticonvulsants, with 4e having $ED_{50}$ values of 17.17 mg/kg and 24.55 mg/kg and protective index ($PI=TD_{50}/ED_{50}$) values of 41.9 and 29.3 in the MES and sc-PTZ tests, respectively, and 4f having $ED_{50}$ values of 19.7 mg/kg and 21.2 mg/kg and PI values of 36.5 and 33.9 in the MES and sc-PTZ tests, respectively. The PI values of 4e and 4f were many fold better than that of the marketed drugs phenytoin, carbamazepine, phenobarbital and valproate, which have PI values in the range of 1.6-8.1 in the MES test and <0.22-5.2 in the sc-PTZ test. Structure-activity relationships were also discussed.

• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.319-322
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• 2005

• Bulletin of the Korean Chemical Society
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• v.11 no.5
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• pp.376-379
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• 1990

To find out a correlation between antibacterial activity and physical properties of 7-substituted 1-ethyl-6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, dipole moments, charge distributions, and hydrophobicities were calculated. The atomic charges and the dipole moments to not give any correlations with inhibition of DNA gyrase, but the calculated hydration free energies show some correlations.

• Journal of the Korean Chemical Society
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• v.38 no.8
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• pp.603-607
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• 1994

New cephalosporin antibiotics,7-[(3,4-dihydro-6-methoxycarbonyl-2,2-dimethyl-2H-1,4-thiazin-3-yl)acetamido]-3-[(substituted pyrimidin-2-yl)thiomethyl]-3-cephem-4-carboxylic acid derivatives(2a∼2d) were synthesized. These new cephalosporin derivatives were prepared by the introduction of pyridinylthiomethyl moiety in 3-position and thiazine group in 7-position of 7-ACA. Antibacterial activities of these compounds were examined and the relationship between structure and activities were studied. As the result, these compounds showed low antibacterial activities compared to cefotaxim used as control.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.501-508
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• 1994

1-Ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazinyl)quinolinea-3-car-boxylic acid-dextran was synthesized by the reaction of 1-ethyl-6-fluoro-1, 4-dihydro-4-oxo-7-(1-piperazinyl )quinoline-3-acryloyl chloride with dextran. Polymeric drug was tested for antimicrobial activity in vitro against ten species of microorganisms. Polymeric drug revealed good antibacterial activity against Bacillus subtillis ATCC 6633, Staphyloccus aureus ATCC 25923, Mycrobactertum phlei IFO 3158, Salmonella typhimurium KCTC 1925, Escherichia coli KCTC 1039, Escherichia coli ESS, Klebsiella puemouiae KCTC 1560 and Pseudomonas aeruginosa IFO 13130. Polymeric drug have no antimicrobial against Candida albicans ATCC 10231, but moderately active Micrococcus luteus ATCC 9341.