• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2835-2840
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• 2010

A series of $MoO_3/CeO_2-ZrO_2$ catalysts with different Mo content (8 - 20 wt %) were prepared by simple co-precipitation followed by impregnation method and were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), energy dispersive spectroscopic (EDS) techniques. The prepared materials were tested for catalytic activity by the synthesis of benzimidazole derivatives using condensation of aromatic aldehydes and o-phenylenediamine by conventional and microwave method. Obtained results reveal that the catalytic activity increases with increase in Mo wt % loading. The best catalytic activity was obtained with 20 wt % $MoO_3/CeO_2-ZrO_2$. The particle size or crystallite size was estimated using Debye-Scherrer equation. After completion of reaction, the catalyst can be recovered efficiently and reused with consistent activity.

• Journal of the Korean Chemical Society
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• v.57 no.6
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• pp.755-760
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• 2013

The present study is synthesis of derivatives of N'-(4-amino-5-sulfanyl-4H-1,2,4-triazole-3-yl)-2-(1H-benzimidazole-2-ylsulfanyl) acetohydrazide (IV). Antibacterial activity tested against the E. coli and A. Substilis. Biological activities conducted by disc diffusion method. Compound $2MB_1$, $2MB_3$, $2MB_5$ inhibit the appreciable microbial growth while rest of the compound possess the moderate activities. Anti-inflammatory activity tested by reduces local edema induced in the rat paw by injection of phlogestic agent. Compound $2MB_1$, $2MB_8$, $2MB_5$, $2MB_3$ and $2MB_6$ exhibit satisfying anti-inflammatory activity while analgesic activity conducted by acetic acid induced writhing effect in mice while compound $2MB_1$, $2MB_4$ and $2MB_7$ having the good analgesic activity. The chemical structures of all newly synthesized compounds were confirmed by their IR, $^1H$ NMR and mass spectral data.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.535-542
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• 1996

Seven isoazamitosene derivatives, mitomycin analogues, were synthesized and tested for cytotoxicities against leukemia and gastric cancer cell lines. Preparation of a pyrrolo[1, 2-a]benzimidazole (3) (azamitosene ring system) was completed by utilizing the Lewis acid-catalized cyclization, with .omicron.-chloronitrotoluene as the starting material. Nitration of 3 produced a mixtue of two isomers (5-nitro isomer (4) and 7-nitro isomer (5)) in product ratio of 36 : 52. 4 was directly converted into quinone (7) by reduction and Fremy oxidaton. Finally, quinone derivatives (8, 9, 10, and 11) were synthesized by 1, 4-addition of 7 with cyclic secondary amines. From above-mentioned 5, 8-nitro compound (15) was prepared in 4 steps. At pH 3, Fremy oxidation of 15 produced quinone (16), whereas iminoquinone derivatives (17a and 17b) at pH 7. Isoazamitosene derivatives (8, 9, 10, and 11), containing cyclic amino groups at the 7-position, showed potent cytotoxicity on P388, SNU-1, and KHH tumor cell lines. Among them, 8 had stronger cytotoxicity against SNU-1 cell line than mitomycin and adriamycin. Considering these results, isoazamitosene derivatives may had unique cytotoxicity profiles. However, isoiminoazamitosene derivatives (17a and 17b) revealed very weak cytotoxicity.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.131-136
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• 2011

Synthesis of N-(1H-benzimidazol-2-yl)-6-substituted-1,3-benzothiazol-2-amines and 6-substituted-N-(4,5-dihydro-1H-imidazol-2-yl)-1,3-benzothiazol-2-amines by the reaction of substituted 2-aminobenzothiazoles with carbon disulphide and methyl iodide followed by the reaction with o-phenylene diamine/ethylene diamine are reported. All the synthesized compounds were characterized by elemental analysis, IR spectra and $^1H$ NMR spectral studies. The potent antibacterial and entomological (antifeedant, acaricidal, contact toxicity and stomach toxicity) activities of the synthesized compounds were investigated.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.236.2-237
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• 2003

Several studies of terbenzimidazoles and bibenzimidazoles suggested that benzimidazoles, especially 5-nitro-2-(para-methoxyphenyl)benzimidazole. possess topoisomerase I inhibition activities. In order to find out the structure activity relationship of 5-nitro-2-phenyl-benzimidazoles. eight derivatives that are substituted at the para position of 2-phenyl moiety were selected, synthesized ＆ evaluated considering their electronic or lipophilic parameters. (omitted)

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.250-257
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• 2002

A series of benzimidazole derivatives carrying different heterocycles such as 1,2,3-thiadiazole, 1,3,4-thiadiazole, thiazolidine, 2,3-dihydro-thiazole, 1,3,4-oxadiazole, semicarbazone and substituted thiosemi-carbazones were synthesized. Also a series of 1-methylbenzimidazole carrying hydroxy ethyl-amide, substituted sulfonyl hydrazide and benzoyl hydrazide from aminobenzoyl group at position 2 of 1-methylbenzimidazole were synthesized. The antimicrobial evaluation of some of the new compounds was carried out.

• Biomolecules & Therapeutics
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• v.4 no.3
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• pp.285-290
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• 1996

This study was designed to determine the effect of newly synthesized antiulcer agent, 5-pyrrolyl-6-halo-2-(pyridyl-2-methylthio)benzimidazole derivatives (IY-81233), on various experimental ulcers and on the secretion of prostaglandin $E_2(PGE_2)$ into the gastric lumen of rat. IY-81233 was previously reported to have a strong inhibitory effect on $H^+/K^$-ATPase and on gastric acid secretion in rats. Oral administration of IY-81233 at concentrations of 0.2, 2.0, and 20 mg/kg inhibited gastric lesions and duodenal ulcer induced by indomethacin, HCI-ethanol, water-immersion stress, cysteamine, and acetic acid in a dose dependent manner. Their IC$IC_{50}$ values were 3.4, 1.4, 0.8, 1.3, and 1.2 mg/kg, respectively. These results indicate that IY-81233 is a potent antiulcer agent although it is slightly less potent than omeprazole in healing of gastritis and ulcers. The secretion of $PGE_2$ into gastric lumen was also investigated in relation to the cytoprotective effect by IY-81233 in rats. The $PGE_2$ level was not changed significantly by an oral administration of IY-81233, suggesting that IY-81233 has little effect on the gastric protection. Therefore, it can be concluded that IY-81233 exerts prominent antiulcer activity by suppressing gastric acid secretion via an inhibition of a proton pump and not by protecting the gastrointestinal mucosa against various ulcerative stimuli.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3684-3692
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• 2010

A series of azole-containing piperazine derivatives have been designed and synthesized. The obtained compounds were investigated in vitro for their antibacterial, antifungal and cytotoxic activities. The preliminary results showed that most compounds exhibited moderate to significant antibacterial and antifungal activities in vitro. 1-(4-((4-chlorophenyl) (phenyl)methyl)piperazin-1-yl)-2-(1H-imidazol-1-yl)ethanone and 1-(4-((4-Chlorophenyl)(phenyl)methyl)piperazin-1-yl)-2-(2-phenyl-1H-imidazol-1-yl)ethanone gave remarkable and broad-spectrum antimicrobial efficacy against all tested strains with MIC values ranging from 3.1 to $25\;{\mu}g/mL$, and exhibited comparable activities to the standard drugs chloramphenicol and fluconazole in clinic. Moreover, 2-((4-((4-chlorophenyl)(phenyl)methyl)piperazin-1-yl)methyl)-1H-benzo[d]imidazole was found to be the most effective in vitro against the PC-3 cell line, reaching growth inhibition values (36.4, 60.1 and 76.5%) for each tested concentration: $25\;{\mu}g/mL$, $50\;{\mu}g/mL$ and $100\;{\mu}g/mL$ in dose-dependent manner. The results also showed that the azole ring had noticeable effect on their antimicrobial and cytotoxic activities, and imidazole and benzimidazole moiety were much more favourable to biological activity than 1,2,4-triazole.

• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.408-413
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• 1995

A few t-amine substituted anilines and amides were synthesized and cyclized to pyrrolo[1,2-a]benzimidazole by heating in various solvents having different polarity. Subsequent nitration of cyclized compound followed by reduction and oxidation of resulting amine afforded quinone such as 7 in 14% yield. The formation of imidazole moiety by thermal cyclization was independent on the solvent polarity. The regiochemistry for the nitration of 4 was unambiguously determined by chemical transformation.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.173-177
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• 2004

The acute toxicities of two major anti-pathogenic veterinary medicines, i.e., ciprofloxacin and enrofloxacin, and six benzimidazole anthelmintics, i.e., albendazole, thiabendazole, flubendazole, febantel, fenbendazole, and oxfendazole, were evaluated with a marine bacterium, Vibrio fischeri, and invertebrate Daphnia magna. These veterinary medical products have been widely used for farm animals, but their impact on aquatic fauna has seldom been investigated. In general, daphnids responded as much as 3 orders of magnitude more sensitively to the tested pharmaceuticals than the microbes. For Daphnia, the most toxic product among the tested anthelmintics was fenbendazole, followed by flubendazole > albendazole ${\approx}$ febantel > thiabendazole > oxfendazole. Daphnids' EC50 values obtained from 48 to 96 hrs of fenbendazole exposure ranged from 2.7 to 6.3 ug/L. The mixture toxicity of the test pharmaceuticals was generally additive in nature and was well predicted by a concentration addition model. Using the predicted no effect concentrations (PNECs) of the benzimidazole derivatives estimated from this study, and predicted environmental concentrations (PECs) of these pharmaceuticals, the risk quotients of each anthelmintics were calculated. Most of the test anthelmintic compounds resulted in risk quotients greater than 1. Especially, risk quotient for fenbendazole was 2,791, which strongly indicates this compound might cause severe ecological consequences, should no future action be taken. This study is the first report on the aquatic toxicities and potential ecological risk of major anthelmintic and antimicrobial veterinary products in Korea. The result of this study provides information necessary for conducting more detailed ecological risk assessment of pharmaceutical products in ambient water and guiding proper management decision.