• Mycobiology
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• 제34권4호
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• pp.185-190
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• 2006

Endophytic fungi were isolated from healthy leaf and root samples of Taraxacum coreanum. Of the 72 isolates recovered, 39 were from leaves and 33 from roots with an isolation frequency of 54% and 46%, respectively. Based on ITS sequence analysis, 72 isolates were classified into 19 genera of which 17 were under the phylum Ascomycota and 2 were under Basidiomycota. Diverse genera were found and Alternaria, Cladosporium, Fusarium and Phoma were dominant. Out of 19 genera, Apodus, Ceriporia, Dothideales, Leptodontidium, Nemania, Neoplaconema, Phaeosphaeria, Plectosphaerella and Terfezia were new to Korea. Seventy two isolates were screened for antifungal activity, of which 10 isolates (14%) were found active at least against one of the tested fungi. Isolate 050603 had the widest antifungal spectra of activity, and isolates 050592 and 050611 were active against three plant pathogenic fungi.

• 대한화학회지
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• 제40권12호
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• pp.711-718
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• 1996

1-phenylpyrrolidine-2,5-diones에 대한 형태분석을 통하여 구조-활성 상관관계를 검토하였다. Antifungel activity에 대한 구조적인 특징으로 활성기인 imide group(-NCO)와 벤젠 moity가 존재하며, 강한활성을 나타내는 유사체의 N원자와 치환기간의 공간거리 N-X4는 5.318~5.320 ${\AA}$, 3,5-치환기간의 거리 X3 -X5는 5.437∼6.072 ${\AA}$을 나타내었다. 또한 여러 파라미터가 검토되었다.

• Fisheries and Aquatic Sciences
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• 제17권2호
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• pp.209-214
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• 2014

With the continuing demand for new solutions in the development of effective and safe candidiasis therapies, we investigated the efficacy of an antifungal agent from the marine brown alga Eisenia bicyclis. The methanolic extract of E. bicyclis evinced potential antifungal activity against Candida species. The ethyl acetate (EtOAc)-soluble extract from E. bicyclis demonstrated the strongest antifungal activity against Candida species among five solvent-soluble extracts. Indeed, the EtOAc-soluble extract showed minimum inhibitory concentrations (MICs) ranging from 4 to 8 mg/mL. Furthermore, the EtOAc-soluble extract considerably reversed high-level fluconazole resistance of Candida species. The MIC values of fluconazole against Candida species decreased substantially (from 64 to $4{\mu}g/mL$) in combination with the MIC of the EtOAc-soluble extract (4 mg/mL). The fractional inhibitory concentration indices of fluconazole ranged from 0.531 to 0.625 in combination with 4, 2, or 1 mg/mL of the EtOAc-soluble extract against Candida isolates, indicating that these combinations exert a marked synergistic effect against Candida isolates. These findings imply that compounds derived from E. bicyclis can be a potential source of natural antifungal agents against Candida species.

• 환경생물
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• 제27권4호
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• pp.384-390
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• 2009

새로운 항진균성 항생물질개발을 목적으로 고추탄저병균인 Colletotrichum gloeosporioides에 대한 항생활성을 가지는 미생물을 토양으로부터 분리하여 동정한 결과, Bacillus sp. CJ-1로 동정하였다. 항생물질의 생산을 위한 배양조건을 검토한 결과, glucose 1.5% (w/v), yeast extract 0.5% (w/v), pH 6.0의 배지를 사용하여 $35^{\circ}C$에서 72시간 진탕 배양하였을 때 항진균활성이 가장 좋았으며, 이때 피검균인 C. gloeosporioides에 대한 배양액의 생육저지환은 약 27.8mm로 최대의 활성을 보여주었다. 피검균인 C. gloeosporioides에 대한 배양액의 생육저지현상을 현미경을 통해 관찰한 결과 배양액 $12.5\;{\mu}L\;mL^{-1}$이상의 농도에서 뚜렷한 생육저해현상을 관찰할 수 있었으며 이는 피검균 포자의 발아억제현상과 연관되어 있을 것으로 추측된다.

• The Plant Pathology Journal
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• 제22권4호
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• pp.323-328
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• 2006

Serratia marcescens W1, isolated from cucumber-cultivated soil in Suwon, Korea, evidenced profound antifungal activity and produced the extracellular hydrolytic enzymes, chitinase and protease. In order to isolate the antifungal genes from S. marcescens W1, a cosmid genomic library was constructed and expressed in Escherichia coli. Transformants exhibiting chitinase and protease expression were selected, as well as those transformants evidencing antifungal effects against the rice blast fungus, Magnaporthe grisea, and the cucumber leaf spot fungus, Cercospora citrullina. Cosmid clones expressing chitinase or protease exerted no inhibitory effects against the growth of fungal pathogens. However, two cosmid clones evidencing profound antifungal activities were selected for further characterization. An 8.2 kb HindIII fragment from these clones conditioned the expression of antagonistic activity, and harbored seven predicted complete open reading frames(ORFs) and two incomplete ORFs. The deduced amino acid sequences indicated that six ORFs were highly homologous with genes from S. marcescens generating pyrroloquinoline quinone(PQQ). Only subclones harboring the full set of pqq genes were shown to solubilize insoluble phosphate and inhibit fungal pathogen growth. The results of this study indicate that the functional expression of the pqq genes of S. marcescens W1 in E. coli may be involved in antifungal activity, via as-yet unknown mechanisms.

• Mycobiology
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• 제43권2호
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• pp.150-156
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• 2015

2',4'-Dihydroxychalcone (2',4'-DHC) was identified from a heat shock protein 90 (Hsp90)-targeting library as a compound with Hsp90 inhibitory and antifungal effects. In the presence of 2',4'-DHC ($8{\mu}g/mL$), radial growth of Aspergillus fumigatus was inhibited 20% compared to the control, and green pigmentation was completely blocked. The expression of the conidiation-associated genes abaA, brlA, and wetA was significantly decreased (approximately 3- to 5-fold) by treatment with 2',4'-DHC. The expression of calcineurin signaling components, cnaA and crzA, was also significantly reduced. The inhibitory effects of 2',4'-DHC on metabolic activity and mycelial growth were significantly enhanced by combination treatment with itraconazole and caspofungin. Docking studies indicated that 2',4'-DHC bind to the ATPase domain of Hsp90. These results suggest that 2',4'-DHC act as an Hsp90-calcinurin pathway inhibitor.

• 한국유기농업학회지
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• 제11권4호
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• pp.61-74
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• 2003

This study was conducted to screen the antagonistic bacteria which inhibit the growth of plant pathogen, fusarium wilt(Fusarium oxysporum) occurred in tomato plants in greenhouse. We isolated an effective bacterial strains and investigated into the antifungal activity of the antagonistic microorganism and it’s identification. Ten bacterial strains which strongly inhibited Fusarium oxysporum were isolated from the nature, and the best antagonistic bacterial strain designated as KC175, was selected. The antagonistic strain KC175 was identified to be the genus Bacillus sp. based on the morphological and biochemical characterization. The Bacillus sp. KC175 showed 58.2% of antifungal activity against the growth of Fusarium oxysporum. By the bacterialization of the culture broth and the heat bacterialization culture filtrate of it, Bacillus sp. KC175 showed 91% and 18% of antifungal activity, respectively.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.276-281
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• 1999

In order to determine the functional region of the antifungal protein (AFP) isolated from Aspergillus giganteus responsible for growth inhibitory activity and the promotion of phospholipid vesicle aggregation, overlapping peptides covering the complete sequence of AFP were synthesized. The antibiotic activity against bacterial, fungal, and tumor cells, and the vesicle-aggregation activity of the synthetic peptides were investigated. The AFP functional sequence responsible for antibiotic and vesicle-aggregation activity was determined to be located within the region between AFP residues 19 to 32. AFP (19-32) exhibited an a-helical conformation in a cell membrane-like environment. AFP (19-32) displayed potent antibiotic activity against bacterial, fungal, and tumor cells without peptide toxicity as indicated by hemolysis. Accordingly, AFP (19-32) could be used as a good model for the design of effective antibiotic agents with powerful antibiotic activity yet without any cytotoxic effects against the host organism.

• 한국미생물·생명공학회지
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• 제35권1호
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• pp.26-29
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• 2007

Tautomycetin(TMC)은 국내 토양에서 분리된 방선균(Streptomyces sp. CK4412)로부터 생합성 되는 항진균성 2차 대사산물로서, Cyclosporin및 FK506과 같은 기존의 면역억제제보다 작용 메카니즘 및 효능이 훨씬 탁월한 선형의 폴리케타이드계 면역억제 화합물이다. 고체배지의 pH변화와 TMC생산성과의 상관관계를 규명하기 위하여, 방선균 CK4412를 다양한 pH조건에서 배양하면서 항진균 활성 및 TMC생산량을 비교분석 하였다. 고체배지의 pH를 산성조건(pH 4-5)으로 유지하여 방선균 CK4412 균주를 배양할 경우, 중성 pH 조건에서 배양한 경우보다 훨씬 탁월한 항진균 활성 및 TMC생산성이 관찰되었다. 본 연구결과는 대표적인 방선균 S. coelicolor에서 입증된 pH-shock게 의한 2차대사산물의 생산성 증대효과가 대사산물의 특성과 균주가 전혀 다른 TMC 생산균주 CK4412에서도 관찰됨을 입증함으로써, pH조절에 의한 다양한 종류의 방선균 유래 유용 생리활성물질의 생산성 증대 전략을 제시하고 있다.

• Journal of Applied Biological Chemistry
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• 제49권4호
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• pp.165-170
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• 2006

The antifungal activity of crude methanolic extract and fractions from Yucca smalliana Fern. leaves, roots and flowers were investigated in vitro against a panel of plant pathogenic fungi. The minimal inhibitory concentration(MIC) was determined by an agar dilution method. Preliminary liquid culture and agar plate assays showed that the growth of Fu sarium oxysporum, Phytophthora capsici, Rhizoctonia solani and Botrytis cinerea were inhibited by Y. smalliana extracts. The extracts from flowers and leaves showed antifungal activity of 64.0% and 34.0% against F. oxysporum, 66.0% and 62.0% against P. capsici, and 27.0% and 41.0% against B. cinerea, respectively. The methanolic extract from Y. smallina leaves in distilled water was fractionated using solvents of increasing polarity: hexane, ethyl acetate and butanol. These fractions had a broad spectrum of antifungal activity, found to reside entirely in the butanol and aqueous fraction. The aqueous fraction showed inhibition rate of 60.0, 67.8, 84.6 and 58.3% against F. oxysporum, R. solani, C. gloeosporioides, and B. cinerea, respectively, and the butganol fracgtion showed 36.0, 46.0, 66.1 and 58.3%, respectively. Phenolics(e.g. flavonoids, steroids and terpenoids) were observed in the thin layer profile of the different fractions. Leave extract showed a prominent antioxidant activity totally scavenging the free radical of DPPH at a concentration of 1 mg/ml.