• 생명과학회지
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• 제29권1호
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• pp.84-89
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• 2019

신규 항세균물질을 탐색하는 사전조사에서 몇몇 분리균주들이 그람양성 세균과 그람음성 세균 모두에 항균활성을 보이며, 심지어 methicillin내성 Staphylococcus aureus (MRSA)에도 항균활성을 나타내었다. 이들 균주 중에서 한 균주가 표현형과 계통분석을 이용하여 특히 16S 리보좀 RNA 유전자 염기서열에 기초하여 Pseudomonas aeruginosa로 동정되었다. BCNU 1204 균주의 항균물질은 King's medium B (pH 7.0)에서 $35^{\circ}C$의 온도 조건으로 4일 배양 후 가장 최대로 생산되었다. 항균물질을 각종 유기용매로 분획한 결과, P. aeruginosa BCNU 1204의 dichloromethane (DCM)분획과 ethylacetate (EA) 분획이 그람 양성 세균에 강력한 항균활성을 보였으며, 특히 ethylacetate (EA) 분획이 methicillin내성 Staphylococcus aureus (MRSA)에 대하여 강한 항균활성을 나타내었다. Recycling preparative LC와 preparative TLC 로 활성물질 하나(분획 5-2)를 분리하여 GC-MS 분석한 결과 phenazine 화합물에 속하는 phenazine-1-carboxylic acid 로 동정하였다. 그리고 MRSA 균주에 대한 최소저해농도(minimum inhibitory concentration, MIC)가 MRSA균주인 CCARM 3089, 3090, 3091 그리고 3095 균주에 대하여 각각 $25{\mu}g/ml$, $50{\mu}g/ml$, ${\geq}25{\mu}g/ml$ 그리고 ${\geq}50{\mu}g/ml$ 임을 확인하였다. 그러므로 P. aeruginosa BCNU 1204 분리균주는 항 MRSA 항생물질을 개발하기 위한 잠재 가치가 높은 생물자원으로 기대되며, P. aeruginosa BCNU 1204 균주로부터 리더 화합물을 획득하기 위한 보다 많은 연구가 요구된다.

• 미생물학회지
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• 제48권1호
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• pp.52-56
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• 2012

본 연구는 치아우식증 및 치주질환 원인균들에 대한 carvacrol의 항균능을 알아보고, 사람의 구강조직 세포에서 세포의 생존율을 분석하여 세포독성 정도를 알아보기 위해 실시하였다. Carvacrol의 항균능은 뮤탄스 연쇄상구균과 5종류의 치주질환 원인균을 이용하여 MIC 및 MBC 값을 측정하여 분석하였고, 세포생존율은 정상 사람 치은섬유모세포를 이용하여 MTT 분석법으로 평가하였다. 구강질환 원인균에 대한 carvacrol의 MIC 및 MBC 값은 각각 $16-128{\mu}g/ml$과 $32-128{\mu}g/ml$이었다. 세포독성 실험 결과 carvacrol은 $128{\mu}g/ml$ 농도에서 세포생존율이 현저히 감소하였다. 따라서 carvacrol은 치아우식증과 치주질환 원인균에 대한 항균작용이 뛰어나지만, 구강조직 세포에 대해 세포독성을 가지고 있어 가글린제 및 치약 등의 구강위생용품에 활용하기 위해서는 $64{\mu}g/ml$ 이하의 농도로 사용하고 정상 사람 치은섬유모세포에 대한 독성이 없는 다른 항균물질과 혼합하여 사용하는 것이 효과적일 것으로 생각된다.

• ALGAE
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• 제29권1호
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• pp.47-55
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• 2014

To develop effective and safe acne vulgaris therapies with a continuing demand for new solutions, we investigated unique efficacy of an antibacterial agent from marine brown alga Eisenia bicyclis in treating acne vulgaris. The methanolic extract of E. bicyclis exhibited potential antibacterial activity against acne-related bacteria. The ethyl acetate fraction showed the strongest antibacterial activity against the bacteria among solvent fractions. Six compounds (1-6), previously isolated from the ethyl acetate fraction of E. bicyclis, were evaluated for antibacterial activity against acne-related bacteria. Among them, compound 2 (fucofuroeckol-A [FF]) exhibited the highest antibacterial activity against acne-related bacteria with a minimum inhibitory concentration (MIC) ranging from 32 to $128{\mu}g\;mL^{-1}$. Furthermore, FF clearly reversed the high-level erythromycin and lincomycin resistance of Propionibacterium acnes. The MIC values of erythromycin against P. acnes were dramatically reduced from 2,048 to $1.0{\mu}g\;mL^{-1}$ in combination with MIC of FF ($64{\mu}g\;mL^{-1}$). The fractional inhibitory concentration indices of erythromycin and lincomycin were measured from 0.500 to 0.751 in combination with 32 or $64{\mu}g\;mL^{-1}$ of FF against all tested P. acnes strains, suggesting that FF-erythromycin and FF-lincomycin combinations exert a weak synergistic effect against P. acnes. The results of this study suggest that the compounds derived from E. bicyclis can be a potential source of natural antibacterial agents and a pharmaceutical component against acnerelated bacteria.

• Fisheries and Aquatic Sciences
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• 제25권11호
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• pp.579-586
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• 2022

Research on the potential biological activity of red alga Symphyocladia spp. has been limited to Symphyocladia latiuscula, which is widely used as a food ingredient in Korea. Here, we examined the biological activity of another species, Symphyocladia linearis, which is found in Korea and was reported as a new species in 2013. The aim of this study was to evaluate the antioxidant, anti-inflammatory, and antibacterial properties of a 70% ethanol extract of S. linearis. Antioxidant activity, which was evaluated using radical scavenging assays, revealed half maximal inhibitory concentration values for 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) of 34.57 and 11.70 ㎍/mL algal extract, respectively. Anti-inflammatory activity of the S. linearis ethanolic extract was evaluated using RAW 264.7 cells by measuring the inhibition of lipopolysaccharide-induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production. The potential cytotoxicity of NO and PGE₂ was first examined, confirming no toxicity at concentrations ranging from 10-100 ㎍/mL. NO production was inhibited 61.1% and 78.0% at 50 and 100 ㎍/mL S. linearis extract, respectively; and PGE₂ production was inhibited 69.1%, 83.2%, and 94.8% at 25, 50, and 100 ㎍/mL S. linearis extract, respectively. Thus, the S. linearis extract showed very strong efficacy against PGE₂ production. The cellular production of reactive oxygen species, measured using 2',7'-dichlorofluorescin diacetate fluorescence, was inhibited 48.8% by the addition of 100 ㎍/mL S. linearis extract. Antibacterial activity was evaluated using the disc diffusion method and minimum inhibitory concentration (MIC). S. linearis was effective only against gram-positive bacteria, exhibiting antibacterial activity against Staphylococcus aureus with a MIC of 256 ㎍/mL extract and against Bacillus cereus with a MIC of 1,024 ㎍/mL extract. Based on these results, we infer that a 70% ethanolic extract of S. linearis possesses strong anti-inflammatory properties, and therefore has the potential to be used in the prevention and treatment of inflammatory and immune diseases.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1563-1572
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• 2018

Gold nanoparticles (AuNP) and their conjugates have been gaining a great deal of recognition in the medical field. Meanwhile, extended-spectrum ${\beta}$-lactamases (ESBL)-producing bacteria are also demonstrating a challenging problem for health care. The aim of this study was the biosynthesis of AuNP using Rosa damascenes petal extract and conjugation of ceftriaxone antibiotic (Cef-AuNP) in inhibiting ESBL-producing bacteria and study of in vitro anticancer activity. Characterization of the synthesized AuNP and Cef-AuNP was studied. ESBL-producing strains, Acinetobacter baumannii ACI1 and Pseudomonas aeruginosa PSE4 were used for testing the efficacy of Cef-AuNP. The cells of MCF-7 breast cancer were treated with previous AuNP and Cef-AuNP at different time intervals. Cytotoxicity effects of apoptosis and its molecular mechanism were evaluated. Ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy established the formation of AuNP and Cef-AuNP. Transmission electron microscope demonstrated that the formed nanoparticles were of different shapes with sizes of 15~35 nm and conjugation was established by a slight increase in size. Minimum inhibitory concentration (MIC) values of Cef-AuNP against tested strains were obtained as 3.6 and $4{\mu}g/ml$, respectively. Cef-AuNP demonstrated a decrease in the MIC of ceftriaxone down to more than 27 folds on the studied strains. The biosynthesized AuNP displayed apoptotic and time-dependent cytotoxic effects in the cells of MCF-7 at a concentration of $0.1{\mu}g/ml$ medium. The Cef-AuNP have low significant effects on MCF-7 cells. These results enhance the conjugating utility in old unresponsive ceftriaxone with AuNP to restore its efficiency against otherwise resistant bacterial pathogens. Additionally, AuNP may be used as an alternative chemotherapeutic treatment of MCF-7 cancer cells.

• 공업화학
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• 제30권2호
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• pp.254-259
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• 2019

본 연구에서는 마그네슘-층상규산염(MgP) 층간에 솔잎 추출물(PLE)이 삽입되어 겹겹이 쌓여있는 샌드위치 구조의 나노입자(PLE/MgP)를 one-pot으로 합성하였다. XRD 분석을 통해 팔면체와 사면체 구조로 MgP가 성공적으로 합성되었으며, PLE가 층간에 삽입되어 MgP 간의 층간거리(d-spacing)가 벌어진 것을 확인하였다. HR-TEM을 통해 모폴로지 변화를 관찰하였으며, 열중량분석법을 통해 PLE가 MgP 대비 10%까지 함유된 것을 확인하였다. 최소저해농도(MIC) 및 최소 사멸농도(MBC) 분석을 통해 피부 상재균에 대한 항균 활성을 검토한 결과 MgP 또는 PLE보다 PLE/MgP의 항균 활성이 더욱 향상된 것을 확인하였다. 이러한 결과는 본 연구에서 개발한 PLE/MgP 유/무기 복합 소재가 화장품 소재, 의료용 소재 등의 다양한 분야에 적용 가능함을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제33권1호
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• pp.61-74
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• 2023

The global increase in multidrug-resistant (MDR) bacteria has inspired researchers to develop new strategies to overcome this problem. In this study, 23 morphologically different, soil-isolated actinomycete cultures were screened for their antibacterial ability against MDR isolates of ESKAPE pathogens. Among them, isolate BOGE18 exhibited a broad antibacterial spectrum, so it was selected and identified based on cultural, morphological, physiological, and biochemical characteristics. Chemotaxonomic analysis was also performed together with nucleotide sequencing of the 16S rRNA gene, which showed this strain to have identity with Streptomyces lienomycini. The ethyl acetate extract of the cell-free filtrate (CFF) of strain BOGE18 was evaluated for its antibacterial spectrum, and the minimum inhibitory concentration (MIC) ranged from 62.5 to 250 ㎍/ml. The recorded results from the in vitro anti-biofilm microtiter assay and confocal laser scanning microscopy (CLSM) of sub-MIC concentrations revealed a significant reduction in biofilm formation in a concentration-dependent manner. The extract also displayed significant scavenging activity, reaching 91.61 ± 4.1% and 85.06 ± 3.14% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), respectively. A promising cytotoxic ability against breast (MCF-7) and hepatocellular (HePG2) cancer cell lines was obtained from the extract with IC₅₀ values of 47.15 ± 13.10 and 122.69 ± 9.12 ㎍/ml, respectively. Moreover, based on gas chromatography-mass spectrometry (GC-MS) analysis, nine known compounds were detected in the BOGE18 extract, suggesting their contribution to the multitude of biological activities recorded in this study. Overall, Streptomyces lienomycini BOGE18-derived extract is a good candidate for use in a natural combating strategy to prevent bacterial infection, especially by MDR pathogens.

• Corrosion Science and Technology
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• 제4권3호
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• pp.89-94
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• 2005

This paper presents the results of a study that was undertaken to optimize the ratio of the components of a new multi-component inhibitor blend composed of orthophosphate/ phosphonates/ acrylate copolymer/ isothiazolone. The effects of newly developed inhibitor on carbon steel dissolution in synthetic cooling water were studied through weight loss tests, electrochemical tests, scale tests, and micro-organism tests. The obtained results were compared to blank (uninhibited specimen) and showed that developed inhibitor revealed very good corrosion, scale, and micro-organism inhibition simultaneously. All measurements indicated that the efficiency of the blended mixture exceeded 90 %. The inhibitive effects arose from formation of protective films which might contain calcium phosphate, calcium phosphonate, and iron oxide. The nature of protective films formed on the carbon steel was studied by scanning electron microscopy (SEM) and auger electron spe ctroscopy (AES). Inhibitor used in this study appeared to have better performance for scale inhibition due to their superior crystal modification effect and excellent calcium carbonate scale inhibition properties. The effect of inhibitor on microorganisms was evaluated through minimum inhibitory concentration (MIC) test. All kinds of micro-organisms used in this study were inhibited under 78ppm concentration of inhibitor.

• 한국응용과학기술학회지
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• 제37권6호
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• pp.1635-1645
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• 2020

In this study would like to find extending or increasing the efficacy of the antibiotic substance for the strains with resistance to antibiotics or persister cells by inhibition of the resistance. This study was used different species of 'legal high' plants leaves from Leonotis leonurus, Mitragyna speciosa, and seeds from Ipomoea murucoides with antibiotics which are Amoxicillin, Chloramphenicol, Ciprofloxacin, Kanamycin, Oxacillin, and Vancomycin. Legal highs were extracted with methanol. Minimum inhibitory concentration(MIC) testing for a range of antibiotics with extracts of plant was fulfilled by broth dilution methods. In this essay, it was determined in a microdilution assay utilizing suspended in ISB up to a final concentration of 512㎍/ml in 96 wells microtitre plates, threefold and serial dilutions. After that, the microplates were kept in incubator between 35℃ and 37℃ for overnight. Leonotis leonurus, Mitragyna speciosa, and Ipomoea murucoides of Legal highs (512㎍/ml) investigated small activity to inhibit against pathogens which are susceptible Staphylococcus aureus, resistant Staphylococcus aureus, susceptible Enterococcus faecalis, resistant Escherichia coli.

• 생약학회지
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• 제52권1호
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• pp.41-48
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• 2021

This research was conducted to investigate the antibacterial and anti-inflammatory effects of MeOH Ex. of Salvia miltiorrhiza (MESM) against oral pathogenic bacteria. Minimum inhibitory concentration (MIC), removal effect of biofilm produced by Streptococcus mutans, effect of gene expression of proinflammatory cytokines and effect of production of proinflammatory cytokine of MESM were tested. MESM showed moderated antibacterial activity against oral pathogenic bacteria. About 89±8% of biofilms produced by S. mutans were removed by MESM at a concentration of 1 mg/mL. Gene expression of IL-1β and TNF-α induced by Porphyromonas gingivalis were 8~9 folds reduced by MESM. Gene expression of IL-8 induced by Fusobacterium nucelatum were 12 folds reduced by MESM. Production of IL-1β, TNF-α and IL-8 were significantly suppressed by MESM. Conclusively, MESM showed potent antibacterial and anti-inflammatory effect against oral pathogenic bacteria.