• 한국토양비료학회지
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• 제49권4호
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• pp.393-400
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• 2016

Fusarium graminearum is the main cause of substantial economic loss in wheat production. The aim of this study is to investigate biocontrol potential of Lysobacter antibioticus HS124 against F. graminearum and to purify an antifungal compound. In preliminary study, n-butanol crude extract revealed destructive alterations in the hyphal morphology of F. graminearum and almost degraded with $1,000{\mu}g\;mL^{-1}$ concentration. For further study, the antifungal compound extracted from the n-butanol crude extract of L. antibioticus HS124 was identified as N-Butyl-tetrahydro-5-oxofuran-2-carboxamide ($C_9H_{16}NO_3$) using NMR ($^1H-NMR$, $^{13}C-NMR$, $^1H-^1H\;COSY$, HMBC, and HMQC), and HR-ESI-MS analysis. To our knowledge, N-Butyl-tetrahydro-5-oxofuran-2-carboxamide may be a novel compound with molecular weight of 186.1130. The minimum inhibitory concentration value of antifungal compound was $62.5{\mu}g\;mL^{-1}$ against F. graminearum. In an in vivo pot experiment, crown rot disease from F. graminearum was inhibited when wheat seeds were treated with both HS124 culture and F. graminearum. Growth of wheat seedling was enhanced by treatment of HS124 compared to control. Our results suggest that L. antibioticus HS124 characterized in this study could be successfully used to control F. graminearum and could be used as an alternative to chemical fungicides in modern agriculture.

• Journal of Applied Biological Chemistry
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• 제57권2호
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• pp.159-160
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• 2014

An antifungal antibiotic was extracted three times using n-butanol from the culture broth of Bacillus sp. Bioassayguided column chromatography with silica gel and Sephadex LH-20 yielded 62 mg of the original active compound from 1 L of culture broth. The minimal inhibitory concentration values were 25 and $50{\mu}g/ml$ against Pyricularia oryzae and Pellicularia filamentosa, respectively. Based on results obtained from the analysis of the structure of the antibiotic using MS, NMR, and IR spectroscopy, the antifungal antibiotic was shown to consist of only six of fructose.

• 한국자기공명학회논문지
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• 제18권2호
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• pp.82-88
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• 2014

Three bicyclic and one monocyclic sesquiterpenoids were isolated from the marine sponge Topsentia species. Their planar structures were completely determined from a combination of extensive 1D and 2D NMR experiments, and also the relative stereochemistry on the chiral centers were established by the ROESY experiment. Compound 1 was determined as a new stereoisomer. Furthermore, the NMR spectral data for compounds 2 and 4, of which have not been reported, were listed. Four compounds did not show any cytotoxicity, instead compound 4 exhibited moderate antifungal activity against Candida albicans.

• 동의생리병리학회지
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• 제20권2호
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• pp.467-470
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• 2006

Bioactivity directed isolation has led to the isolation of (-)-ent-costunolide (1) as the major active compound. This compound (1) inhibited the growth of the dermatophytic fungus Trichophyton mentagrophytes ATCC 28185, (4 mm inhibition zone at $15\;{\mu}g/disc$).

• 생명과학회지
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• 제14권1호
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• pp.193-197
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• 2004

A continuous enrichment culture procedure was used to isolate bacteria from various soil sources capable of suppressing large patch disease of turfgrass. Six isolates consistently suppressed large patch in turfgrass, and ranged in the spectrum of extracellular enzymes that they expressed. The best disease- suppressing isolate, TBM912, expressed protease, CMCase, and pectinase activity and inhibited the growth of Rhizectonin solani and Betrytis cinerea in vitro. Here we show that this strain also produces an antibiotic that was identified by TLC, SDS-PACE and HPLC analysis as lipopeptide.

• 한국식물병리학회지
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• 제14권3호
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• pp.191-202
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• 1998

About 300 actinomycetes were isolated from two forest and one sea-shore soil and tested for inhibitory effects on mycelial growth of six plant pathogenic fungi Magnaporthe grisea, Alternaria mali, Colletotrichum gloeosporioides, Phytophthora capsici, Fusarium oxysporum f. sp. cucumerinum, and Rhizoctonia solani. Among 300 actinomycetes tested, only 16 actinomycetes showed the antifungal activity against the test fungi. Isolate NH 50 was selected for production and purification of antifungal antibiotic substances. Actinomycete isolate NH 50 displayed the broad antifungal spectra against 11 plant pathogenic fungi. To identify actinomycete isolate NH 50, cultural characteristics on various agar media, diaminopimelic acid type, and morphological characteristics by scanning electron microscopy were examined. As a result, actinomycete isolate NH 50 was classified as a rare actinomycete that had LL-DAP type and did not produce spores. After incubation of isolate NH 50 in yeast extract-malt extract-dextrose broth, antifungal compound NH-B1 that inhibited mycelial growth of some plant pathogenic fungi was purified from the methanol eluates of XAD-16 resins by a series of purification procedures, i.e., silica gel flash chromatography, C18 flash chromatography, Sephadex LH-20 column chromatography, silica gel medium pressure liquid chromatography (MPLC), C18 MPLC, and high pressure liquid chromatography (HPLC). UV spectrum and 1HNMR spectrum of antifungal compound NH-B1 dissolved in methanol were examined. The antibiotic NH-B1 showed the major peaks at 230 and 271.2nm. Based on the data of 1H-NMR spectrum, NH-B1 was confirmed to be an extremely complex polymer of sugars called polysaccharides. The antibiotic NH-B1 showed strong antifungal activity against Alternaria solani and Cercospora kikuchi, but weak activity against M. grisea.

• The Plant Pathology Journal
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• 제28권1호
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• pp.93-100
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• 2012

The rhizobacterium NJ134, showing strong $in$ $vitro$ antifungal activity against $Fusarium$ $oxysporum$, was isolated from field grown tomato plants and identified as $Pseudomonas$ sp. based on 16S ribosomal DNA sequence and biochemical analyses. The antifungal compound purified by gas chromatography-mass spectrometry, infrared, and nuclear magnetic resonance analyses from NJ134 cultures was polyketide 2,4-diacetylphloroglucinol (DAPG). Analysis of the sequence of part of one of the genes associated with DAPG synthesis, $phlD$, indicated that the DAPG producer NJ134 was a novel genotype or variant of existing genotype termed O that have been categorized based on isolates from Europe and North America. A greenhouse study indicated that about $10^8$ CFU/g of soil NJ134 culture application was required for effective biocontrol of Fusarium wilt in tomato. These results suggest that a new variant genotype of a DAPG-producing strain of $Pseudomonas$ has the potential to control Fusarium wilt under the low disease pressure conditions.

• Applied Biological Chemistry
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• 제42권4호
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• pp.271-276
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• 1999

새로운 천연물 농약 또는 생산군주를 개발하기 위하여 Streptomyces 속의 여러 균주를 대상으로 항진균 물질을 탐색하여 항진균 물질 생산 균주 Streptomyces hygroscopicus MJM1004를 선발하였다. 항진균 물질의 생산을 위한 발효 배지를 선정하기 위하여 여러 탄소원, 질소원과 무기원을 대상으로 균체 생장 정도와 항진균 물질의 생산성을 조사하였으며, 생산 배지는 2% soybean meal, 1% glucose, 2% starch, 0.3% $CaCO_3$, 0.05% $MgSO_4{\cdot}7H_2O$, 0.05% $K_2HPO_4$를 조성으로 하였다. S. hygroscopicus MJM1004 균주의 균체에서 추출된 항진균 물질은 Candida albicans와 여러 식물 병원성 곰팡이들에 대하여 광범위한 저해 효과를 나타내었다. S. hygroscopicus MJM1004 균체로부터 분리된 항진균 물질, SH-1004를 핵자기공명법($^1H,\;^{13}C$, DQF COSY, HMQC 및 HMBC)을 통하여 분석한 결과 azalomycin F complex 임을 확인할 수 있었다. Positive FAB mass spectrum을 통하여 SH-1004는 azalomycin F4a와 F5a가 1.8 : 1의 비율로 혼합된 물질임을 확인하였다.

• Applied Biological Chemistry
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• 제46권3호
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• pp.268-270
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• 2003

굴피나무 지상부의 메탄을 추출물을 n-hexane, ethylacetate, n-butanol, $H_2O$으로 순차적으로 용매분획하였다. Ethylacetate 분획으로부터 silica gel chromatography를 반복하여 활성물질을 분리 정제하였다. 화합물은 NMR과 MS의 기기분석 결과 5-hydroxy-2-methoxy-1,4-naphthoquinone로 구조결정 되었다. 이 화합물은 in vivo 실험결과 토마토역병에 대하여 $100\;{\mu}g/ml$에서 76%의 방제효과를 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1217-1220
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• 2007

The saprophytic fungus Ulocladium atrum Preuss is a promising biological control agent for Botrytis cinerea in greenhouse- and field-grown crops. However, despite its known potent antifungal activity, no antifungal substance has yet been reported. In an effort to characterize the antifungal substance from U. atrum, we isolated an antibiotic peptide. Based on extensive spectroscopic analyses, its structure was established as a cyclopeptolide with a high portion of N-methylated amino acids, and its $^1H$ and $^{13}C$ chemical shifts were completely assigned based on extensive 1D and 2D NMR experiments. Compound 1 exhibited potent antifungal activity against the plant pathogenic fungus Botrytis cinerea and moderate activity against Alternaria alternate and Magnaporthe grisea.