• Natural Product Sciences
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• 제23권2호
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• pp.113-118
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• 2017

A new tetracyclic triterpenoid [4,4,24-trimethylcholesta-${\Delta}^{8,9;14,5;24,28}$-trien-$3{\beta},11{\beta},12{\alpha}$-triol-12-acetate, 3-sulfate] sodium salt (1), together with eight known compounds including ergosterol $5{\alpha},8{\alpha}$-endoperoxide (2), 1,9-dihydroxy-3-methoxy-2-methylpterocarpan (3), 3-O-${\beta}$-D-2-acetyl-amino-2-deoxyglucopyranoxyloleanoic acid (4), hydnocarpin (5), derrone (6), isovitexin (7), erythrinin C (8), and 5,4'-dihydroxy-2"-hydroxyisopropyldihydrofurano [4,5:7,8]-isoflavone (9), were isolated from the EtOAc soluble fraction of the methanol extract of aerial part of Desmodium uncinatum collected in the western highland of Cameroon. The structures of these compounds were established by comprehensive interpretation of their spectral data mainly including 1D- ($^1H$ and $^{13}C$), 2D-NMR($^1H$-$^1H$ COSY, HMQC, HMBC) spectroscopic and ESI-TOF-MS mass spectrometric analysis. The isolation of an integracide-like compound from plant origin is a very unusual finding.

• 한국미생물·생명공학회지
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• 제25권6호
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• pp.592-597
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• 1997

During the screening of inhibitors against phospholipase C (PLC) and the formation of inositol phosphates (IP$_{t}$) at NIH3T3${\gamma}$1 cells from microbial secondary metabolites, we selected a fungal strain MT60109 which was capable of producing an inhibitor. By the taxonomic studies, this fungus was identified as Pseudallescheria sp. MT60109 and an inhibitor of PLC was purified by BuOH extraction and chromatographic techniques from the culture broth of Pseudallescheria sp. MT60109. The inhibitor was identified as thielavin B by the physico-chemical properties and spectroscopic analysis of UV, FAB-MS, $^{1}$H, $^{13}$C-NMR, $^{1}$H-$^{1}$H COSY and HMBC. Thielavin B showed potent inhibitory activity against PLC purified from bovine brain with an IC$_{50}$ of 20 $\mu$M. And it also inhibited the formation of inositol phosphates in platelet-derived growth factor (PDGF) -stimulated NIH3T3${\gamma}$1 cells with an IC$_{50}$ of 20 $\mu$M.

• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1111-1119
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• 2006

Beauvericins and enniatins are cyclohexadepsipeptides exhibiting various biological activities on animal systems, including humans. Fusarium oxysporum FB1501 (KFCC 11363P) that produces four different cyclohexadepsipeptides was isolated from soil in Korea and the structures of the four cyclohexadepsipeptides elucidated by HPLC, MS, IR, and NMR analyses. The molecular weights for compounds 1,2,3, and 4 were determined to be 654.5, 784.5, 668.6, and 682.5, respectively, on the basis of ESI-MS measurements. The IR spectra for all the compounds exhibited absorptions for ester $(1,733-1,743\;cm^{-1})$ and amide $(1,649-1,655\;cm^{-1})$ bonds that were very similar to those for beauvericin and enniatins with ester and amide absorptions. The results of the NMR analysis $(^{1}H,\;^{13}C,\;135-DEPT,\;COSY,\;HMQC,\;and\;HMBC;\;in\;COCl_{3})$ revealed that compounds 1,3, and 4 consisted of $_{L}-N-methyl\;valine$ (N-MeVal), $_{D}-{\alpha}-hydroxyisovaleic\;acid$ (Hiv), and 2-hydroxy-3-methylpentanoic acid (Hmp) residues (compound 1: three N-MeVal residues, two Hiv residues, and one Hmp residue; compound 3: three N-MeVal residues, one Hiv, and two Hmp residues; compound 4: three N-MeVal residues and three Hmp residues). Therefore, the compounds were identified as enniatin H (compound 1), enniatin I (compound 3), and enniatin MK1688 (compound 4). Compound 2 was analyzed as beauvericin according to 1D and 2D NMR analyses. This study is the first report related to the co-production of beauvericin with other unusual enniatins, such as enniatin H, enniatin I, and enniatin MK1688, by Fusarium oxysporum.

• 한국미생물·생명공학회지
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• 제19권6호
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• pp.598-603
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• 1991

신규 미생물 Bacillus subtilis subsp. krictiensis의 배양액으로부터 식물 및 인체 병원균에 폭넓은 항진균 활성을 나타내는 DRF-001으로 총칭되는 6개의 cyclic peptide의 복합체(A에서 F)를 분리하였다. 이 6개 peptides의 분자량은 FAB-MS 측정결과, A가 1042, B와 C가 1056, D와 E가 1070 그리고 F가 1084였다. 이 복합체의 구조를 각종 자기분석을 통해 해석한 결과, 구조 중에 1몰씩의 glutamine, proline, tyrosine, serine 및 unusal $\beta$-amino acid와 3몰의 asparagine을 공통적으로 갖고 있으나, $\beta$-amino acid의 탄소수와 말단 methyl 구조에 차이점이 있음을 알 수있었다. 구성 amino acid들의 서열과 입체구조 결정에 의하여 KRF-001의 잠정구조를 결정하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.615-618
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• 2016

Ethyl acetate extracts obtained from culture of endophytic fungi Aspergillus sp isolated from Piper crocatum Ruiz & Pav, have been shown to possess cytotoxic activity against T47D breast cancer cells. Investigations were here conducted to determine bioactive compounds responsible for the activity. Bioassay guided fractionation was employed to obtain active compounds. Structure elucidation was performed based on analysis of LC-MS, $^1H$-NMR, $^{13}C$-NMR, COSY, DEPT, HMQC, HMBC data. Cytotoxity assays were conducted in 96 well plates against T47D and Vero cell lines. Bioassay guided isolation and chemical investigation led to the isolation of pyrophen, a 4-methoxy-6-(1'-acetamido-2'-phenylethyl)-2H-pyran-2-one. Further analysis of its activity against T47D and Vero cells showed an ability to inhibit the growth of T47D cells with IC50 values of $9.2{\mu}g/mL$ but less cytotoxicity to Vero cells with an $IC_{50}$ of $109{\mu}g/mL$. This compound at a concentration of 400 ng/mL induced S-phase arrest in T47D cells.

• 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.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.314-321
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• 2008

Acaricidal effects of materials derived from Diospyros kaki roots against Dermatophagoides farinae and D. pteronyssinus were assessed using impregnated fabric disk bioassay and compared with that of the commercial benzyl benzoate. The observed responses varied according to dosage and mite species. The $LD_{50}$ values of the chloroform extract of Diospyros kaki roots were 1.66 and $0.96{\mu}g/cm^2$ against D. farinae and D. pteronyssinus. The chloroform extract of Diospyros kaki roots was approximately 15.2 more toxic than benzyl benzoate against D. farinae, and 7.6 times more toxic against D. pteronyssinus. Purification of the biologically active constituent from D. kaki roots was done by using silica gel chromatography and high-performance liquid chromatography. The structure of the acaricidal component was analyzed by GC-MS, $^1H-NMR,\;^{13}C-NMR,\;^1H-^{13}C$ COSY-NMR, and DEPT-NMR spectra, and identified as plumbagin. The acaricidal activity of plumbagin and its derivatives (naphthazarin, dichlon, 2,3-dibromo-1,4-naphthoquinone, and 2-bromo-1,4-naphthoquinone) was examined. On the basis of $LD_{50}$ values, the most toxic compound against D. farinae was naphthazarin $(0.011{\mu}g/cm^2)$ followed by plumbagin $(0.019{\mu}g/cm^2),$ 2-bromo-1,4-naphthoquinone $(0.079{\mu}g/cm^2)$, dichlon $(0.422{\mu}g/cm^2)$, and benzyl benzoate $(9.14{\mu}g/cm^2)$. Additionally, the skin color of the dust mites was changed from colorless-transparent to dark brown-black by the treatment of plumbagin. Similar results have been exhibited in its derivatives (naphthazarin, dichlon, and 2-bromo-1,4-naphthoquinone). In contrast, little or no discoloration was observed for benzyl benzoate. From this point of view, plumbagin and its derivatives can be very useful for the potential control agents, lead compounds, and indicator of house dust mites.

• 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.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2737-2742
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• 2011

Ring-opening metathesis polymerization (ROMP) of an ethyl-substituted tetracyclododecene (8-ethyltetracyclo[$4.4.0.1^{2,5}.1^{7,10}$] dodec-3-ene, Et-TCD) was carried out in the presence of a ternary catalyst system consisting of $WCl_6$, triisobutyl aluminium (iso$Bu_3Al$), and ethanol. The optimal molar ratio of Et-TCD/$WCl_3$/iso-$Bu_3Al$/ethanol was found as 500/1/3/2 at which the yield of ring-opened polymer was 100%. 1-Hexene was shown to be an effective molecular weight controlling agent for ROMP reaction of Et-TCD. The hydrogenation of the ring opened polymer (p-Et-TCD) was conducted successfully using Pd(5 wt %)/${\gamma}$-$Al_2O_3$ at $80^{\circ}C$ for 1 h. Chemical structures of p-Et-TCD and its hydrogenated product($H_2$-p-Et-TCD) were characterized using 2D NMR techniques ($^1H-^1H$ COSY and $^1H-^{13}C$ HSQC). The changes of physical properties such as thermal stability, glass transition temperature and light transmittance after the hydrogenation were also investigated using TGA, DSC, and UV.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.69-79
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• 2012

In an ongoing survey of the bioactive potential of microorganisms from Ladakh, India, the culture medium of a bacterial strain of a new Pseudomonas sp., strain ICTB-745, isolated from an alkaline soil sample collected from Leh, Ladakh, India, was found to contain metabolites that exhibited broad-spectrum antimicrobial and biosurfactant activities. Bioactivity-guided purification resulted in the isolation of four bioactive compounds. Their chemical structures were elucidated by $^1H$ and $^{13}C$ NMR, 2D-NMR (HMBC, HSQC, $^1H$,$^1H$-COSY, and DEPT-135), FT-IR, and mass spectroscopic methods, and were identified as 1-hydroxyphenazine, phenazine-1-carboxylic acid (PCA), rhamnolipid-1 (RL-1), and rhamnolipid-2 (RL-2). These metabolites exhibited various biological activities like antimicrobial and efficient cytotoxic potencies against different human tumor cell lines such as HeLa, HepG2, A549, and MDA MB 231. RL-1 and RL-2 exhibited a dose-dependent antifeedant activity against Spodoptera litura, producing about 82.06% and 73.66% antifeedant activity, whereas PCA showed a moderate antifeedant activity (63.67%) at 60 ${\mu}g/cm^2$ area of castor leaf. Furthermore, PCA, RL-1, and RL-2 exhibited about 65%, 52%, and 47% mortality, respectively, against Rhyzopertha dominica at 20 ${\mu}g/ml$. This is the first report of rhamnolipids as antifeedant metabolites against Spodoptera litura and as insecticidal metabolites against Rhyzopertha dominica. The metabolites from Pseudomonas sp. strain ICTB-745 have interesting potential for use as a biopesticide in pest control programs.