• Journal of Microbiology and Biotechnology
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• 제16권1호
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• pp.158-162
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• 2006

Cyclic dipeptides isolated from Streptomyces sp. have been shown to have antimicrobial activity as well as other potentially useful biological activities. The purpose of this study was to compare the in vitro activity of two cyclic dipeptides combined against anaerobic bacteria with the activity of other antimicrobial agents. Specifically, the in vitro activity of the combination of two cyclic dipeptides was investigated against 140 clinical isolates of anaerobic bacteria by the agar dilution method and was compared with that of erythromycin, cefoxitin, imipenem, clindamycin, and metronidazole. The cyclic dipeptide combination and imipenem were the most active antimicrobial agents tested. In addition, the cyclic dipeptide combination had a radioprotective effect on five normal human lung fibroblast cells, showing survival rates higher $(>90\%)$ than either of the two cyclic dipeptides alone $(<80\%)$.

• 한국식품영양학회지
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• 제11권6호
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• pp.629-634
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• 1998

1-Deoxynojirimycin which is a potent intestinal ${\alpha}$-glucosidase inhibitor was purified from the culture broth by ion exchange chromatography, Sephadex LH20 column chromatography, TSK gel chromatography and HPLC respectively. Acute toxicity of 1-deoxynojirimycin, which was loaded through the oral as dose of 200mg/kg, was investigated in IRC mouse. None of the tested IRC mice were not dead and increase of body weight showed also the same results in comparison with control mice. The antimicrobial susceptibility of 20 pathogenic strains against 3 antidiabetic compounds (1-deoxynojirimycin, AO-128, acarbose) were obtained by agar dilution method. All of the three antidiabetic compounds has very weak antimicrobial activity (MIC>100$\mu\textrm{g}$/ml).

• 약학회지
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• 제21권1호
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• pp.1-16
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• 1977

The effect of condensates of phosphates on the preservative activity of the food additives, using eight micro-organisms, has been studied by the agar dilution method. It was found that condensates of phosphates increased the food preserving action of almost all of preservatives and they acted as a synergist for the action of almost all of preservatives. Disodium dihydrogen prrophosphate acted as the strongest synergist in the experiment. But sodium tripolyphosphate anhydrous, sodium poly-phosphate, sodium tripolyphosphate and sodium hexametaphosphate acted as a inhibitor for action of some preservatives on some orgnisms. The preservatives were sodium dehydroacetate (DHA), potassium sorbate and NaNO$_{2}$ etc. The action of sodium meta-phosphate on the preservatives produced a mean difference by their origins. It was supposed that such a difference was produced by the difference of amount of impurities that were contained in sodium metaphosphate, It was also supposed that the does of the preservatives could be reduced by addition of condensates of phosphates, acting as a synergist for the action of almost all of the preservatives.

• 대한수의학회지
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• 제17권1호
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• pp.13-16
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• 1977

In order to know the current status of sensitivity of Corynebacterium renale to some antimicrobial agents of current use, the sensitivity of 37 strains isolated from urine and vaginal cavity of healthy Korean native cattle and dairy cattle was studied by agar plate dilution method, and their sensitivity according to serological types was compared. The antimicrobial agents tested were streptomycin (SM), erythromycin (EM), oxytetracycline (OT), penicillin G (PC), gentamycin (GM), kanamycin (KM), ampicillin (AP), leucomycin (LM), chloramphenicol (CM), colistin (CL), sulfadimethoxine (SDM) and sulfadiazine (SDZ). Most strains were highly sensitive to PC, GM, AP, LM and KM, and moderate to CM and OT, but resistant to SM, EM, CL, SDM and SDZ. Serological type II was more sensitive to EM, SDM and SDZ than type I and II, but more resistant to SM.

• Archives of Pharmacal Research
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• 제28권7호
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• pp.765-769
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• 2005

The essential oil fraction of Ostericum koreanum was analyzed by GC-MS. Inhibiting activities of this oil and its main components were tested by the broth dilution assay and disk diffusion test against one antibiotic-susceptible and two resistant strains of Salmonella enteritidis and S. typhimurium, respectively. The GC-MS analysis revealed thirty-four compounds; the main components were $\alpha$-pinene (41.12%), $\rho$-cresol (17.99%) and 4-methylacetophenone (7.90%). The essential oil of O. koreanum and its main components were significantly effective against the tested antibiotic-susceptible strains as well as against the resistant strains of the two Salmonella species, with MICs (minimum inhibitory concentrations) ranging from 2 mg/mL to 16 mg/mL. The anti-Salmonella effects of the oils were dose-dependent on $M\"{u}ller-Hinton$ agar plates in this experiment. Additionally, checkerboard titer test results demonstrated significant combined effects of streptomycin and O. koreanum oil or cresol, one of the main components of this oil, against the two streptomycin resistant strains of S. typhimurium, with FICIs ranging from 0.12 to 0.37.

• Archives of Pharmacal Research
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• 제16권2호
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• pp.161-163
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• 1993

In order to evaluate the antimicrobial effect of 2,3-disubstituted-1,4-naphthalenedione derivatives, we synthesized several 2-chloro, 2-bromo and 2-hydroxy-3(substituted)-1, 4-naphthalene-diones (1-25). These derivatives were tested for antifugal and antibacterial activities, in vitro, against Candida albicans 10231 and local, Aspergillus niger KCTC 1231, Tricophyton mentagrophytes KCTC 6085, Baciilus subtilis ACTT 6633, Pseudomonas aeruginsa NCTC 10490, Staphylococcus aureus ATCC 6538P, Escherichia coli NIHJ. The MIC values were determined by the two-fold agar dilution/strea method. Among these derivatives, 4, 5 and 6 showed the potent antifungal activities. Also 5 and 6 had the antibacterial activities. 5 with (1,2,4-triazolyl)-amino moirty was the most effective in preventing the growth of fungi, such as Candida albicans, Aspergillus niger and Tricophyton mentagrophytes.

• 대한의생명과학회지
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• 제25권3호
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• pp.275-281
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• 2019

This study was performed to characterize the chromosomal metallo-${\beta}$-lactamases (MBLs) of Chryseobacterium indologenes isolated from Korea and to propose a clustering method of IND MBLs based on their amino acid similarities. Chromosomal MBL genes were amplified by PCR from 31 clinical isolates of E. indologenes. Nucleotide sequencing was performed by the dideoxy chain termination method using these PCR products. Antimicrobial susceptibilities were determined by the agar dilution method. PCR experiments showed that all 31 E. indologenes isolates contained all $bla_{IND}$ genes. DNA sequence analysis revealed that E. indologenes isolates possessed ten types of $bla_{IND}$ gene, including seven novel variants ($bla_{IND-8}$ to $bla_{IND-14}$). The most common combination of MBL was IND-2 (n = 18). Minimum inhibitory concentrations of imipenem and meropenem for the isolates harboring novel IND MBLs were ${\geq}16{\mu}g/mL$. IND MBLs were grouped in three clusters, based on amino acid similarities.

• 대한약침학회지
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• 제25권2호
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• pp.101-105
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• 2022

Objectives: This study aims to determine the Fractional Inhibitory Concentration Index (FICI) of combinations of Melastoma malabathricum leaf fraction with ciprofloxacin or gentamicin against pathogenic bacteria, Escherichia coli, Staphylococcus aureus, and Bacillus cereus, isolated from Diabetic Foot Ulcer (DFU) patients. Methods: We tested concentrations of 45%, 55%, 65%, and 75% of gentamicin and ciprofloxacin using dilution and agar diffusion methods. The combination of M. malabathricum leaf extract with these antibiotics was tested in vitro against all three bacteria. Results: The combination of M. malabathricum leaf extract and ciprofloxacin gave a FICI value of 0.5, indicating synergistic antibacterial activity against the test bacteria. Conclusion: The results show that the antibacterial effect of a combination of high doses of the leaf extract with either antibiotic is greater than that of the leaf extract and the antibiotics in single use.

• Journal of the Korean Wood Science and Technology
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• 제40권4호
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• pp.276-286
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• 2012

본 연구에서는 표재성 진균에 의한 피부질환 개선용 소재로의 개발을 위해 삼나무 정유의 표재성 알레르기성 진균, Trichophyton schoenleinii, Trichophyton tonsurans, Trichophyton mentagrophytes (interdigitale), Trichophyton rubrum, Epidermophyton floccosum, Aspergillus fumigatus에 대한 항진균 활성을 평가하여 삼나무 정유의 표재성 진균에 의한 피부질환 개선 소재로의 개발 가능성을 평가하고자 하였다. 항진균 활성 평가는 삼나무 정유의 MIC (Minimum Inhibitory Concentration) 측정과 TLC bioassay, 한천희석법을 통해 측정하였다. 또한 활성 성분의 주성분을 확인하기 위해 GC/MS 분석을 실시하였다. 삼나무 정유 crude oil의 MIC는 모든 균에서 500 ppm 이하의 농도 값을 나타냈으며, TLC bioassay를 통해 spot 1에서 항진균 효과를 확인하였다. 한천희석법을 통한 항진균 활성은 A. fumigatus를 제외한 모든 진균에 대해 삼나무 정유 crude oil의 경우, 500 ppm 이상에서 100%의 활성을 나타냈고, 분획 D의 경우, 100 ppm에서도 100%의 활성을 나타냈다. TLC bioassay를 통해 항진균 활성을 나타낸 spot 1과 한천희석법을 통해 활성을 나타낸 분획 D를 GC/MS로 분석한 결과 주성분은 elemol, ${\gamma}$-eudesmol, ${\beta}$-eudesmol이었다. 따라서 elemol, eudesmol 등은 표재성 진균에 의한 피부질환의 개선 소재로의 이용 가능성이 충분하다고 사료된다.

• 농약과학회지
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• 제11권1호
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• pp.18-26
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• 2007

콩 검음뿌리썩음병의 방제를 위한 살균제 선발을 위하여 실내 및 온실 검정을 실시하였다. 한천희석법과 96-well microtiter plate법을 이용하여 총 25종의 살균제의 병원균에 대한 생육 억제 효과를 검정하였다. 보호용 살균제 중에서 iminoctadine을 제외한 dithianon, dichlofluanid, mancozeb, captan 등은 한천희석법에서 조사한 병원균의 생육을 억제하는 $EC_{50}$값은 $500{\mu}g\;mL^{-1}$ 이상으로 효과가 매우 낮았지만, 96-well microtiter plate법에서는 4.65, 0.61, 4.64, $0.29{\mu}g\;mL^{-1}$로, 병원균의 포자 발아에 대하여 매우 높은 활성을 보였다. 그러나 ergosterol 생합성을 저해하는 살균제 (EBI) 그룹은 물질에 따라 매우 다른 살균활성을 보였다. Difenconazole의 경우에는 균사생육보다는 포자발아 억제활성이 높았고, prochloraz의 경우에는 균사 생육활성과 포자 발아억제활성이 서로 유사하였다. 이에 비하여 다른 EBI 살균제들은 포자발아보다는 균사생육저해활성이 큰 것으로 나타났다. Carbendazim과 diethofencarb의 혼합제와 dazomet만이 두 가지의 실내 검정법 모두에서 우수한 효과를 보였다. Carbendazim과 diethofencarb의 혼합제를 비롯한 8종의 살균제를 선발하여 온실검정을 실시한 결과, carbendazim과 diethofencarb의 혼합제만이 병원균을 접종하기 2일 전과 후에 토양에 처리하였을 때, 75와 76.7%의 효과를 보였고, tebuconazole은 병원균을 접종하고 2일 후에 관주처리 하였을 때, 83.3%의 효과를 보였다.