• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.267-272
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• 2012

Vitex trifolia L. is a full grown fruit of Vitex rotundifolia L. (Verbenaceae). It has been used for treating headache, dizziness, toothache and removal of fever as a traditional medicine in Korea. V. trifolia (500 g) were extracted three times with 80% aqueous MeOH at room temperature. The MeOH extract (38 g) was successively partitioned with n-hexane, EtOAc, n-BuOH and $H_2O$. Both n-hexane and EtOAc fractions showed more than 80% antifungal activity in vivo against several plant pathogens at 2000 ppm. Successive repeated silica gel, Sephadex LH-20, preparative TLC, and preparative HPLC of these fractions led to isolation of three compounds. Using mainly mass spectroscopy and nuclear magnatic resonance (NMR) spectroscopy, their chemical structures were determined as agnuside(1), chrysosplenol B(2), and artemetin(3). Compound 2 was isolated for the first time from V. trifolia. Study on in vitro and in vivo antifungal activities of the isolated compounds is in progress.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.18-22
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• 2007

The optimum production condition for the antibiotic from Bacillus thuringiensis BK4 was determined, and the suppression rate of Fusarium-wilt by the butanol-extracted antibiotic was verified by employing tomatoes in vitro and in vivo pot tests. Cell growth and antifungal activity were the best when 0.5% xylose and 0.2% peptone No.3 were given as carbon and nitrogen sources, respectively, in the presence of 5mM $CaCl_2$. The partially purified antibiotic successfully prevented Fusarium oxysporum pathogen in pot experiments. When the pots were treated with both live cells and the partially purified antibiotic, an additive-effect was seen in the suppression of Fusarium-wilt, but synergistic effect was not detected. The antibiotic, denoted BK4, purified by Sephadex LH-20 column chromatography was eluted with a single peak at a retention time of 38 min. on prep-HPLC; Minimum inhibition concentration of the homogenous antibiotic was determined to be 50${\mu}$g/ml.

• Journal of the Korean Chemical Society
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• v.55 no.5
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• pp.781-786
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• 2011

An easy and efficient route for the synthesis of some imidazo[1,2-c]pyrazolo[4,3-e]pyrimidines 3-6, imidazo[1,2-c]pyrazolo[4,3-e]triazine 8, pyrazolo[4,3-e]triazolo[1,5-c]pyrimidines 12-15 and pyrazolo-[3',4':4,5]pyrimido[1,6-b]triazines 16, 17 was described through the reaction of readily available 5-aminopyrazole-4-carbonitrile 1 with different reagents. The in vitro antimicrobial activity of some synthesized compounds was examined. Most of the tested compounds proved to be active as antibacterial and antifungal agents.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.80-84
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• 1997

Series of new chiral N-substituted benzotriazol-1-yl derivatives were synthesized and their fungicidal activities in vitro against gray mold(Botrytis cinerea), black spot(Alternaria kikuchiana) and phytophthora blight(Phytophthora capsici) were measured by the agar medium dilution method. The substituents effects between the fungicidal activities (obs. $pI_{50}$) and a various physicochemical parameters of phenoxy or thiophenoxy group(X) & alkyl or phenyl group(Y) were analyzed by the multiple regression technique. From the analyzed substituent effects, the structure-activity relationship(SAR) equations shows that the antifungal activities depend on the parameters for the optimal molecular hydrophobicity($({\Sigma}logP)_{opt}$), Van der Waals (${\Sigma}Vw$>0) volume(${\AA}^3$) and inductive constant with electron withdrawing group(${\sigma}_I$,Y>0). The activity in affected by the inductive effect (${\sigma}_I$,Y>${\sigma}_g$X) of Y-group rather than the X-group. The phenoxy substituents, 1, showed higher antifungal activity tn the thiophenoxy substituents, 2. For 1, polar substituent constant(${\sigma}^*$) was an important factor in determining the activity. And the tribromomethyl substituent, 1g showed the highest activity against the tee fungi.

• Molecules and Cells
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• v.43 no.9
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• pp.831-840
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• 2020

The β-class of carbonic anhydrases (β-CAs) are zinc metalloenzymes widely distributed in the fungal kingdom that play essential roles in growth, survival, differentiation, and virulence by catalyzing the reversible interconversion of carbon dioxide (CO₂) and bicarbonate (HCO₃^-). Herein, we report the biochemical and crystallographic characterization of the β-CA CafA from the fungal pathogen Aspergillus fumigatus, the main causative agent of invasive aspergillosis. CafA exhibited apparent in vitro CO₂ hydration activity in neutral to weak alkaline conditions, but little activity at acidic pH. The high-resolution crystal structure of CafA revealed a tetramer comprising a dimer of dimers, in which the catalytic zinc ion is tetrahedrally coordinated by three conserved residues (C119, H175, C178) and an acetate anion presumably acquired from the crystallization solution, indicating a freely accessible "open" conformation. Furthermore, knowledge of the structure of CafA in complex with the potent inhibitor acetazolamide, together with its functional intolerance of nitrate (NO₃^-) ions, could be exploited to develop new antifungal agents for the treatment of invasive aspergillosis.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.172-176
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• 2004

Bacterial isolates TRL2-3 and TRK2-2 showing anti-fungal activity in vitro test against some plant pathogens were identified as Pseudomonas putida and Micrococcus luteus, respectively. Pre-treatment with both bacterial isolates at the concentration 1.0$\times$ $10^7$ and $10^6$cfu/ml in the rhizosphere could trigger induced systemic resistance in the aerial part of cucumber plants against anthracnose caused by Colletotrichum orbiculare. However, the pre-treatment with the higher concentration at 1.0 $\times$ $10^8$ cfu/ml of both isolates could not induce resistance after challenge inoculation with C. orbiculare. As a positive control, the treatment with DL-3 amino butyric acid caused a remarkable reduction of disease severity whereas the lesions on the leaves of untreated plants developed apparently after the fungal inoculation. From these results, it was recomended that disease control using both bacterial isolates inducing systemic resistance in the field where chemical application is forbid.

• Mycobiology
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• v.36 no.4
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• pp.260-265
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• 2008

Cyclic voltammetric measurements were performed for Co(II), Ni(II), Cu(II) and Zn(II) complexes of 1 : 1 alternating copolymer, poly(3-nitrobenzylidene-1-naphthylamine-co-succinic anhydride) (L) and Ni(II) and Cu(II) complexes of 1 : 1 alternating copolymer, poly(3-nitrobenzylidene-1-naphthylamine-co-methacrylic acid) ($L^1$). The in vitro biological screening effects of the investigated compounds were tested against the fungal species including Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans and bacterial species including Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa by well diffusion method. A comparative study of inhibition values of the copolymers and their complexes indicates that the complexes exhibit higher antimicrobial activity. Copper ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium. The nuclease activity of the above metal complexes were assessed by gel electrophoresis assay and the results show that the copper complexes can cleave pUC18 DNA effectively in presence of hydrogen peroxide compared to other metal complexes. The degradation experiments using Rhodamine B dye indicate that the hydroxyl radical species are involved in the DNA cleavage reactions.

• The Plant Pathology Journal
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• v.36 no.3
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• pp.231-243
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• 2020

Rice blast, caused by Magnaporthe oryzae, is one of the most destructive rice diseases worldwide. The aim of this study was to screen bacterial isolates to efficiently prevent the occurrence of rice blast. A total of 232 bacterial isolates were extracted from nonrhizospheric rice soil and were screened for antifungal activity against M. oryzae using a leaf segment assay. Strains S170 and S9 showed significant antagonistic activity against M. oryzae in vitro and in leaf disk assays, and controlled M. oryzae infection under greenhouse conditions. The results showed that strains S170 and S9 could effectively control rice leaf blast and panicle neck blast after five spray treatments in field. This suggested that the bacterial strains S170 and S9 were valuable and promising for the biocontrol of rice disease caused by M. oryzae. Based on 16S rDNA, and gyrA and gyrB gene sequence analyses, S170 and S9 were identified as Bacillus amyloliquefaciens and B. pumilus, respectively. The research also demonstrated that B. amyloliquefaciens S170 and B. pumilus S9 could colonize rice plants to prevent pathogenic infection and evidently suppressed plant disease caused by 11 other plant pathogenic fungi. This is the first study to demonstrate that B. amyloliquefaciens and B. pumilus isolated from nonrhizospheric rice soil are capable of recolonizing internal rice stem tissues.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.285-295
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• 2016

To investigate the effect of dietary fiber from mozuku, Cladosiphon novae-caledoniae kylin (C. novae-caledoniae kylin) on the skin care, we measured anti-oxidant activity, anti-microbial activities, tyrosinase activity inhibition and elastic activity. B16F10 melanoma cell (MTT assay) were used to measure cell viability. MC and MI exhibited in vitro antibacterial activity against Staphyloccus aureus (S. aureus) and MRSA without antifungal activity. Mozuku extract (MS) showed excellent tyrosinase inhibition effect compared to arbutin as a positive control (to 49% for tyrosine). The wrinkle-improving effect was relatively low. However, wrinkle-improving effect was relatively low. DPPH free radical scavenging activity was 89% in a concentrations at $500{\mu}g/mL$. These results indicate that the mozuku extracts may be an effective cosmetic ingredient for skin whitening.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.48-51
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• 2011

This study was performed to functional improvement by fermenting of SCB (Slurry Composting and Biofiltering) liquid fertilizer. After screening of cellulose decomposing test using microorganisms originated from composts produced with turf grass clipping, five kinds of Cellulose Decomposing Microorganisms (CDMs) were selected. The optimum medium for CDMs culture was Tryptic soy broth. The optimum fermenting time of CDMs in SCB liquid fertilizer was 36 hour. In addition, CDMs showed antimicrobial activity in vitro. Sclerotinia homoeocarpa, Rhizoctonia solani AG2-2(IV) and Pythium spp. were inhibited by CDMs, but Rhizoctonia solani AG2-2(IIIB) in vitro uneffected by CDMs we isolated.