• Journal of the Korean Wood Science and Technology
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• v.40 no.4
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• pp.276-286
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• 2012

In this study, the antifungal activity of Cryptomeria japonica essential oil against superficial and allergic fungi, Trichophyton schoenleinii, Trichophyton tonsurans, Trichophyton mentagrophytes, Trichophyton rubrum, Epidermophyton floccosum, and Aspergillus fumigatus, was evaluated for determining the potential compound as dermatitis treatment. Minimum Inhibitory Concentration (MIC) measurement, TLC bioassay and agar dilution methods were used for determining the antifungal activity of crude essential oil and its fractions from C. japonica. Also, their major constituents were analyzed by GC/MS. The MICs were below 500 ppm at all superficial fungi, and spot 1 of C. japonica essential oil showed highly effective antifungal activity by TLC bioassay. In antifungal activity by agar dilution methods, crude oil showed high antifungal effect at more than 500 ppm and fraction D was significantly effective at even 100 ppm except for A. fumigatus. The major compounds of spot 1 and fraction D of C. japonica oil determined by GC/MS were elemol, ${\gamma}$-eudesmol, and ${\beta}$-eudesmol, which could be used as atopic dermatitis treatment material.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.821-832
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• 1997

The aim of this study was to separate or purify some bioactive compounds from flowers of alfalfa(Medicago sativa L.) and to test of the isolated compounds on alfalfa for their autotoxicity and on Echinochloa crus-galli for their allelopathy for seed germination and seedling weight. Using thin layer chromatography(TLC) of $CHCl_3$ extracts, the most inhibitory band to alfalfa seed germination was determined. Germination inhibition of this extract suggested a complex chemical interaction. Separation and purification of compounds with CHCl$_3$ extract of fresh alfalfa flowers were conducted by a silica gel TLC, and microcrystalline cellulose TLC(MCTLC), followed by droplet countercurrent chromatography(DCCC) bioassay. Preliminary identification was done by high perfomance liquid chromatography(HPLC) on the most inhibitory fractions in DCCC. Ferulic acid, caffeic acid, vanillic acid, rutin, narringin were identified in fraction 5 and ferulic acid, caffeic acid, vanillic acid, rutin, coumarin in fraction 6. The phytotoxicity of their individual compound was tested on alfalfa and Echinochloa crus-galli seed germination and seedling weight. Coumarin and ferulic acid showed the most inhibitory effect on alfalfa seed germination and Echinochloa crus-galli seedling fresh and dry weight. These compounds may be, at least in part, involved in autotoxicity and allelopathy.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.105-111
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• 2013

Biofilm formation of multifunctional plant growth promoting rhizobacterium (PGPR), Pseudomonas fluorescens 2112 is necessary for P. fluorescens 2112 to have a positive impact on the rhizosphere of red-pepper. This study investigated whether signal molecules of the quorum sensing AHLs are produced in order to confirm biofilm formative ability. Through the use of Petri dish bioassays a blue circle formed evidence of AHLs. It was confirmed that P. fluorescens 2112 produced six-carbon-chain-long AHLs by TLC bioassay. The bacterial density of P. fluorescens 2112 on the top and bottom of pepper plant roots was estimated as $3{\times}10^5$ and $8{\times}10^3$ CFU/g root, respectively. P. fluorescens 2112 exist more with high-density of $3.5{\times}10^6$ CFU/g soil at a depth of 1 cm but at a low-density of $1.1{\times}10$ CFU/g soil at a depth of 5 cm, from the surface of rhizosphere soil. In addition, biofilm formation of P. fluorescens 2112 on the epidermises and the tips of the red-pepper roots were confirmed visually by SEM. Thus, the production of AHLs by P. fluorescens 2112 brings about quorum sensing signaling and the formation of biofilm on the roots which has a positive effect on economically important crops such as red-pepper by additionally producing a variety of antifungal substances and auxin.

• Journal of Life Science
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• v.18 no.2
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• pp.206-212
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• 2008

The quorum sensing (QS) regulatory network has been the subject of extensive studies during recent years and has also attracted a lot of attention because it both positively and negatively regulates various putative virulence factors, although initially considered to be a specialized system of Vibrio fischeri and related species. In this study, to identify the novel materials which inhibit QS system of microorganisms, extracts of eighteen natural products were tested by bioassay using N-(3-oxohexanoyl)-$_L$-homoserine lactone and N-(3-oxooctanoyl)-$_L$-homoserine lactone synthesized in this experiment and an Agrobacterium tumefaciens NT1 biosensor strain containing a traI::lacZ fusion. The result indicated that the extracts of cabbage, leek, and onion exhibited the QS inhibition activity. Thus, materials contained in the extracts were isolated via recycling preparative HPLC and were purified via a JAIGEL-LS255 column. The common fraction corresponding to a peak of the 83 min point of them quenched the quorum sensing of A. tumefaciens NT1 biosensor strain in ABMM containing X-gal and was designated quorum sensing inhibitor-83 min (QSI-83). The QSI-83 exhibited the heat stability and did not inhibit the growth of A. tumefaciens NTl. Furthermore, thin layer chromatography (TLC) results suggested that these novel materials may be antagonists of N-acyl homoserine lactone or may inhibit the QS autoinducer synthesis by Pseudomonas syringae pv. tabaci.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.163-171
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• 1988

The paralytic shellfish poisoning was occurred among 25 laborers who worked at breaking-up of ships in Pusan for 5 days from March 29 to April 2 of 1956. For the purpose of accurately defining the paralytic shellfish poison(PSP) , the authors carried out mouse bioassay and chemical analysis. The results were summarized as follows: 1. The mean amount of Paralytic shellfish toxin was $1,207.8{\mu}g$ Per 100gm meat, and the mean death time of mouse was 5 minutes 16 second. 2. The properties of the PSP were mainly gonyautoxin group by chemical analysis(TLC, IR, $^{1}H-NMR$).

• Journal of the Korean Wood Science and Technology
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• v.49 no.1
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• pp.23-43
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• 2021

In this study, we selected two essential oils, Citrus unshiu and Cinnamomum cassia with superior antioxidant effects from the essential oils of 7 wild plants in South Korea and examined their antimicrobial activity against Candida albicans, which causes dermatitis to identify the antimicrobial components in the essential oils. As a result of measuring DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, SC50 value of the Citrus unshiu essential oil was 0.010 mg/mL, while for the Cinnamomum cassia essential oil, SC50 value was 0.09 mg/mL. In addition, when ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity was measured, SC50 value of the Citrus unshiu essential oil was 0.09 mg/mL, while for the Cinnamomum cassia essential oil, it was 0.06 mg/mL, exhibiting high antioxidant activity. For the minimum inhibitory concentration (MIC), the essential oil of Cinnamomum cassia was 1.25 mg/mL and that of Citrus unshiu was 5 mg/mL, demonstrating a high antimicrobial activity of the Cinnamomum cassia essential oil. Through the thin layer chromatography (TLC) bioassay, we assessed the antimicrobial activity against C. albicans according to the fraction components of the two essential oils. Also, by using preparative TLC (prep. TLC), we obtained the active fractions, and by performing GC/MS analysis of the components with the same Rf value, we identified the antimicrobial-active components. As a result, the main components having antioxidant and antimicrobial activities were cinnamyl acetate, eucalyptol, linalool, and citral of the Cinnamomum cassia essential oil and linalool from the Citrus unshiu essential oil. Also, based on the analysis of the fractional components that showed antioxidant and antimicrobial activities in both of the two essential oils, it was found that linalool has antioxidant activity, while cinnamyl acetate, eucalyptol, citral, and geranyl acetate have antioxidant and antimicrobial activities.

• Natural Product Sciences
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• v.8 no.2
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• pp.48-51
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• 2002

Antioxidative properties of fifteen anthraquinone derivatives, including eleven atural anthraquinones isolated from the roots of Morinda elliptica and four from synthetic origin were evaluated using thin layer chromatography (TLC), ferric thiocyanate (FTC) and thiobarbituric acid (TBA) methods. Five of the compounds, nordamnacanthal, damnacanthal, 2-formyl-1-hydroxyanthraquinone, morindone and alizarin showed higher antioxidative activity than standard natural antioxidant, ${\alpha}-tocopherol$, on the FTC assay. Morindone and alizarin showed the strongest antioxidant activity. The results from the bioassay using TBA method correlated well with the results of the FTC method.

• Applied Biological Chemistry
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• v.27 no.1
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• pp.40-44
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• 1984

Experiments on the GA production ability by ectomycorrhizal fungus, Pisolithus tinctorius was carried out to investigate specific physiological phenomena of growth increase in host plants by formation of mycorrhizae, The culture extract of P. tinctorius was purified by solvent fractionation, sephadex LH-20 chromatography, silica gel partition chromatography and TLC, successively. GA activities in the purified GA fractions were monitored by micro-drop bioassay using dwarf rice seedlings, 'Tan-ginbozu'. $30{\sim}60%$ EtOAc election fractions of silica gel pardon chromatography and the zone of Rf $0.1{\sim}0.4,\;0.6{\sim}0.8$ of TLC exhibited the GA-like activities. The GA activities were increased with the more treated amount of culture extracts. This activity in 100ml of culture solution was equivalent to 0.1ng of $GA_3$.

• Research in Plant Disease
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• v.15 no.2
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• pp.112-119
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• 2009

We discovered two novel phytotoxins produced by the pathogenic fungus, Botrytis cinerea. Among the twenty-five B. cinerea isolates, which were obtained from various host plants in 1994 and 1996, twenty-two showed strong or moderate pathogenicity on five plants such as cucumber, tomato, red pepper, tobacco and Chinese cabbage. The culture filtrate of the B. cinerea 2-16 strain showed the most potent phytotoxic activity in a tobacco leaf-wounding assay. Two novel phytotoxins were isolated from the liquid cultures of B. cinerea 2-16 by ethyl acetate extraction, flash silica gel column chromatography, silica gel column chromatography, Sephadex LH-20 column chromatography, preparative TLC and subsequently preparative HPLC. Their chemical structures were determined to be 3-O-acetyl botcinol and 3-O-acetyl botcinolide, respectively, by mass and NMR spectral analyses. These two phytotoxins caused leaf necrosis in a leaf-wounding bioassay, and significant electrolyte leakage from leaf tissues of tobacco. In the two bioassays tested, 3-O-acetyl botcinol exhibited stronger phytotoxic activity than 3-O-acetyl botcinolide. This is the first report on the production of both 3-O-acetyl botcinol and 3-O-acetyl botcinolide from B. cinerea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.4
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• pp.443-449
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• 2012

This study was conducted to investigate the antioxidant and acetylcholinesterase (AChE) inhibitory activities of extracts from various seaweed. The extracts of $Sargassum$ $thunbergii$ (91.3%), $Polysiphonia$ $morrowii$ (90.7%), $Ecklonia$ $cava$ (89.9%), and $Artemisia$ $fukudo$ (85.9%) showed over 80% high radical scavenging activities at the final concentration of 40 ${\mu}g$/mL. The $Artemisia$ $fukudo$ extract showed the highest inhibition activity of 30.2% on AChE at the final concentration of 10 ${\mu}g$/mL. The extract of $Porphyra$ $tenera$, $Costaria$ $costata$, $Monostroma$ $nitidum$, $Ecklonia$ $cava$, and $Agarum$ $clathratum$ against AChE at a concentration of 10 ${\mu}g$/mL exhibited inhibition of 26.6%, 25.3%, 23.4%, 21.7%, 20.4% and 19.9%, respectively. The bioautography results showed that the mixtures of structurally diverse compounds were thought to affect AChE inhibitory activity. These results suggest that extracts from seaweed with their high quality components may be effective in the prevention of Alzheimer's disease and may be used to develop various functional food products.