• Korean Journal of Veterinary Research
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• v.42 no.2
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• pp.171-181
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• 2002

Simultaneous multiresidue analysis using liquid chromatography determination for five benzimidazole anthelmintics(thiabendazole, oxibendazole, albendazole, mebendazole and fenbendazole) in bovine muscle, liver and omasum has been described. Blank or benzimidazole-fortified samples(0.5g) were blended with bulk $C_{18}$($40{\mu}m$, 18% load, endcapped, 2g). A column made from the resultant $C_{18}$/animal tissue matrix was first washed with hexane($8m{\ell}$), following which the benzimidazoles were eluted with acetonitrile($8m{\ell}$). Analytes of extracted sample were determined by liquid chromatography with UV detector at 290nm. Correlation coefficients of standard curves for individual benzimidazole isolated from fortified samples, using internal standardization, were linear($0.991{\pm}0.007$ to $0.996{\pm}0.005$) with average relative percentage recoveries from $62.1{\pm}3.8(%)$ to $92.3{\pm}7.5(%)$ for the concentration range($0.2{\sim}6.4{\mu}g/g$), respectively. Recoveries rates of TBZ, MBZ in liver, OBZ, MBZ in muscle and TBZ, MBZ in omasium from fortified benzimidazole were 92.%, 87.3%, 74.5%, 82.7%, 75.2% and 83.5% at condition II, respectively. Condition II showed higher recoveries rates than condition I. These results indicated that the matrix solid phase dispersion(MSPD) methodology is acceptable for the determination of 5 benzimidazole anthelmintics and may also suitable for other matrixes of food animal origin.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.837-850
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• 2013

Bovine viral diarrhea virus (BVDV), a major pathogen of cattle, is a well-characterized pestivirus which has been used as a good model virus for HCV. The RNA-dependent RNA polymerase (RdRp) plays a key role in the RNA replication process, thus it has been targeted for antivirus drugs. We employed two-dimensional quantitative structure-activity relationship (2D-QSAR) and molecular field analysis (MFA) to identify the molecular substructure requirements, and the particular characteristics resulted in increased inhibitory activity for the known series of compounds to act as effective BVDV inhibitors. The 2D-QSAR study provided the rationale concept for changes in the structure to have more potent analogs focused on the class of arylazoenamines, benzimidazoles, and acridine derivatives with an optimal subset of descriptors, which have significantly contributed to overall anti-BVDV activity. MFA represented the molecular patterns responsible for the actions of antiviral compound at their receptors. We conclude that the polarity and the polarizability of a molecule play a main role in the inhibitory activity of BVDV inhibitors in the QSAR modeling.

• 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.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.826-833
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• 2006

Previously, we synthesized and evaluated several benzofuran derivatives containing heterocyclic ring substituents linked to the benzofuran nucleus at C-2 by a two- to four-atom spacer as potential anti-HIV-1, anticancer and antimicrobial agents. Among these derivatives, NSC 725612 and NSC 725716 exhibited interesting anti-HIV-1 activity. To further investigate the structure-activity relationship, we synthesized several new benzofuran derivatives derived from 2-acetylbenzofuran (2, 3a-c) and 2-bromoacetylbenzofuran (6; 7a,b; 8a,b). The compounds were designed to comprise the heterocyclic substituents directly linked to the benzofuran nucleus at C-2. Moreover, various related benzimidazoles derived from 2-acetylbenzimidazole and from 2-cyanomethylbenzimidazole (12a,b; 13a,b; 15; 16a,b) were also prepared as isosteres. The synthesized compounds were preliminarily evaluated for their in vitro anti-HIV-1, anticancer and antimicrobial activity. Compounds 2, 3a, 3b, and 12b showed weak anti-HIV-1 activity. Compound 6 exhibited mild activity against S. aureus, while compound 15 had mild activity towards S. aureus and C. albicans. However, no significant anticancer activity was observed with any of the tested compounds. From these results, we conclude that the presence of the spacer between the heterocyclic substituent and the benzofuran nucleus may be essential for the biological activity.

• Parasites, Hosts and Diseases
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• v.53 no.2
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• pp.197-200
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• 2015

The prevalence and associated risk factors of Toxocara vitulorum infection in buffalo and cattle calves was studied in 3 provinces in central Cambodia. Fecal samples were collected from 517 calves between the age of 1-15 weeks and processed for nematode egg counts by a modified McMaster method. A total of 64 calves were found to excrete T. vitulorum eggs in their feces (12.4%; 95% exact CI: 9.7-15.5). The mean fecal egg count was 2,798 EPG (SD=16,351; range=0-224,400). A multivariable generalized linear mixed model showed higher odds of T. vitulorum infection for buffalo versus cattle, for animals aged 4-8 weeks versus younger and older ones, and for animals with strongyle infection. There was no association with fecal consistency. Farmers should be aware of the potential impact of T. vitulorum, and treat their calves at the age of 2-3 weeks with anthelmintics such as benzimidazoles or pyrantel.

• Research in Plant Disease
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• v.23 no.2
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• pp.150-158
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• 2017

Pear scab caused by Venturia nashicola has been reported as an important disease of pear resulting in lowering the quality of pear fruits. In this study, it was conducted to investigate the relationship between resistance of V. nashicola and mutation of ${\beta}$-tubulin gene and the fungicide resistance in field isolate group in benzimidazole fungicides. Responce of V. nashicola to carbendazim could be classified into 3 groups as sensitive that does not grow at all on PDA amended with $0.16{\mu}g/ml$ of carbendazim, low resistance that could not grow in $4.0{\mu}g/ml$ medium, and high resistance that can grow even at $100{\mu}g/ml$. Thirty isolates of V. nashicola collected from 3 regions as Wonju, Naju, and Okcheon were highly resistant to carbendazim. Analysis of the nucleotide sequence of ${\beta}$-tubulin gene of V. nashicola showed that there was no difference in the nucleotide sequence between the sensitive and the low-resistant isolate, but GAG at codon 198 (glutamic acid) was replaced with GCG (alanine) in the high-resistant isolate. Among 10 isolates obtained from the Okcheon, 5 isolates showed the substitution of glycine for glutamic acid, which were resistant to carbendazim, but more sensitive to the mixture of carbendazim and diethofencarb than others. Through these results, all isolates of V. nashicola isolated in pear orchard were found to be resistant to benzimidazoles. Also, mutants E198A and E198G at ${\beta}$-tubulin were found to be important mechanisms of V. nashicola resistance against benzimidazole fungicides.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.61-67
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• 2001

Five hundred sixteen isolates of Botrytis elliptica were isolated from infected leaves of Lilium longiflorum from Kangwon alpine areas in Korea during tile seasons from 1998 to 2000 and resistance of these isolates against some fungicides were examined. The isolation frequency of phenotypes resistant to benomyl, procymidone, and diethofencarb were 90.1, 32.4, and 40.9%, respectively. The isolates were divided into six phenotypic groups; RSS, RRS, SSR, SRR, RSR and RRR, representing sensitive (S) or resistant (R) to benzimidazole, dicarboximide, and N-phenylcarbamate fungicides in order. The percentage of six phenotypes were 40.7, 8.5, 7.2, 2.7, 19.8, and 21.1%, respectively. The RSS phenotype was the most frequently isolated, and tile SRR consisted of the extremely minor populations. In comparison studies on tile overwintering ability of each phenotype in relation to the others, the most frequently isolated RSS and SSR had the higher fitness ability than the less frequently isolated RSR, SRR, and RRR. Recently, population increase of tile RSR and RRR phenotypes may have resulted from the increased applications of the mixture of carbendazim and diethofencarb to control benzimidazole-resistant B. elliptica since 1998. The results of this study indicate that careful application of the fungicides is necessary to achieve effective control of leaf blight on lily in Korea.

• The Korean Journal of Pesticide Science
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• v.13 no.2
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• pp.105-110
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• 2009

In 2008, a number of 110 isolates of Colletotrichum gloeosporioides were obtained from infected twigs of persimmon (Diospyros kaki) collected at Sangju and four fungicides (carbendazim, thiophanate-methyl, mancozeb, and propineb) were evaluated to determine their growth effect on fungicide-medium. Among them, the mycelial growth of 68.2 and 35.5% of isolates was inhibited over 91% in response to carbendazim ($415{\mu}g/m{\ell}$) and thiophanate-methyl ($750{\mu}g/m{\ell}$), respectively, compared to untreated control and the correlation between the two benzimidazole fungicides was higher ($r^2=0.7886$). Moreover, in responses to mancozeb ($1,500{\mu}g/m{\ell}$) and propineb ($1,500{\mu}g/m{\ell}$), the inhibition of mycelial growth of 90% and 53.6% of isolates was inhibited over 91%, respectively. But correlation between theses two fungicides was lower ($r^2=0.0174$). There is no cross-resistance response between benzimidazole funficides and mancozeb / propineb.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.515-520
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• 2010

This research investigated benzimidazole residues (albendazole, fenbendazole, flubendazole, thiabendazole, oxibendazole) in livestock products. A total of 270 samples of livestock products (beef, pork and chicken) were purchased from local markets in Korea. Ethyl acetate was used to extract analytes from the sample, after which ethyl acetate extracts were purified using a MCX cartridge. Analytes were detected using liquid chromatography-tandem mass spectrometry. The limit of detection was 0.01-0.04 ppb, the limit of quantification was 0.03-0.13 ppb, the linearity ($r^2$) was 0.9992-1.0000, and the recovery was 70-85%. Residues of benzimidazoles, except for fenbendazole in pork, were not found in any of the 270 livestock samples. Fenbendazole was detected in the range of 1.2 to 3.1 ppb in 12 samples of pork.

• Research in Plant Disease
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• v.12 no.2
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• pp.99-102
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• 2006

In 2005, 90 isolates of Colletotrichum gloeosporioides causing persimmons tree anthracnose were obtained from infected twigs and fruits of persimmon trees. Their responses to nine fungicides, consisting of two benzimidazoles (thiophanate-methyl, carbendazim), three ergosterol-biosynthesis inhibitors (difenoconazole, myclobutanil, tebuconazole), and four protective fungicides (propineb, mancozeb, chlothalonil, and dithianon), were investigated with relative mycelial growth index to untreated control on PDA treated with field application rate of each fungicide. At response to carbendazim ($415{\mu}g/ml$) and thiophanate-methyl ($750{\mu}g/ml$), 82% and 78% of isolates showed relative mycelial growth index under 0.1 to untreated control, respectively. All of them did not grow on PDA incorporated with myclobutanil ($40{\mu}g/ml$) and tebuconazole ($75{\mu}g/ml$). Only one isolate (PER 36) grew on PDA amended with difenoconazole ($50{\mu}g/ml$), but its relative mycelial growth index to untreated control was very low with a values of 0.03. They were most sensitive to propineb ($1,500{\mu}g/ml$) among four protective fungicides.