• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.36-45
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• 2001

This study was conducted to search new target enzymes of novel herbicide candidate. Total of 107 biochemical inhibitors reported to inhibit over than 100 different plant enzymes were purchased from commercial chemical companies. 15 inhibitors and 34 enzymes were selected by germination assay, seedling assay, wheat leaf disc assay, and whole plant assay. Among them, seven compounds of purine, phehyl-hydrazine, o-phenanthroline, oleylamine, dicyclohexylcarbodiimide, 7,8-benzoquinoline, and aminooxyacetic acid showed high herbicidal activity in the whole plant assay under greenhouse while 7,8-benzoquinone, 8-hydroxyquinoline, 2,2'-dipyridyl, and o-phenanthroline inhibited seed germination of barnyardgrass, rice, and tomato at concentrations of 1.25 to $5{\mu}M$. The compounds of 7,8-benzoquinoline, chlorpromazine, cyanuric fluoride, 4-methylpyrazole, oleylamine, tranylcypromine, and trifluoperazine inhibited the growth of cyanobacteria at 30 to $100{\mu}M$. The compounds of dicyclohexylcarbodiimide and chlorpromazine exhibited whitening effect on tile wheat leaf disc at $100{\mu}M$. These results suggest that the plant-specific enzyme inhibitors which have biological activities may supply the target enzyme for developing new herbicide candidate.

• Journal of Food Hygiene and Safety
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• v.11 no.2
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• pp.129-132
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• 1996

Recently, as concern about the residual antibiotics in milk increase, the detection methods of residual antibiotics used extensevely at the present time were investigated and compared to their properties and the detection limits of variable antibiotics. At first, comparactive tests of the detectable sensitivity of 4 test organisms, B. cereus, B. subtilis, M.luteus, B.stearothermophilus C-953, were performed by disc assay. As a result, B.stearothermophilus was the most sensitive strain of all other strains and showe the detect limit of 5-50 ppb for penlicillins (PCs). And also, B.subitilis was showed the more effective detection limit, 200-400 ppb, for aminoglycosides (AGs) and M.luteus was showed predominant sensitivity , 50-500 ppb for macrolides(MLs) and B.cereus was the most sensitive strain for tetracyclines (TCs) and showed the detection limit of 100-400 ppb. Therefore, each test strains were showed a different sensitivity in the detection of the different antibiotic families. When the detection limit of disc assay and other methods were compared, TTCmethod was less sensitive than other methods showing 5-50 ppb detectable lebel for PCs. Also, for the detection of other antibiotic families TTC method was showed the worst sensitivity and Delvo and Charm Farm tests were similar to the detectable properties of AGs and MLs. Although disc assay was showed the similar detection limit for PCs with Delvo and Charm Farm, it was more widely effective for the detection of kanamycin, erythromycin, chlortetracycline, doxycycline, verginiamycin and so on than Delvo or Charm Farm. CharmII test was showed the best sensitivity for the most of antibiotics except neomycin and gentamycin. But it was necessary that different tests must be performed to each antibiotic family and so it was regarded that the effectiveness of that method was low.

• Korean journal of food and cookery science
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• v.27 no.4
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• pp.17-26
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• 2011

This study was performed to analyze the antibacterial activity against food hazardous microorganisms and antimutagenic effects of Sanguisorba officinalis L. ethanol extracts on Salmonella Typhimurium TA100. The antibacterial activity was evaluated by paper disc diffusion assay, minimum inhibition concentration (MIC), and optical density of the culture with the ethanol extract for 24 hr. Antibacterial activity was tested with seven microorganisms including Escherichia coli, Escherichia coli O157:H7, Pseudomonas aeruginosa, Salmonella Typhimurium, Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus. The paper disc diffusion assay showed distinct clear inhibition zones around the discs treated with the extract for five microorganisms, except Escherichia coli and Escherichia coli O157:H7. MIC values were 0.625-2.5 mg/mL for these five strains that showed clear zones. The time-kill assay was consistent with the results from the paper disc diffusion assay and MIC test. Additionally, antimutagenicity of the extract was determined using the Ames test. The ethanol extract at 5 mg/plate inhibited 72.42% and 89.85% of mutagenicity induced by 4-nitroquinoline 1-oxide and sodium azide, respectively. These results demonstrate that the ethanol extract from S. officinalis L. has remarkable antibacterial activity and antimutagenicity.

• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1340-1344
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• 2000

Objective : A prospective biochemical assay of prostaglandin $E_2$ content in symptomatic lumbar disc materials was done in order to clarify the pathogenesis of lumbar radiculopathy. Patients and Methods : Forty-eight disc specimens were purified by a standard solid-phase extraction procedure and analyzed by an enzymelinked immunosorbent assay for prostaglandin $E_2$. Clinical and anatomic correlations were evaluated with analysis of variance and t-test. Results : Acute herniated lumbar disc diseases tended to be associated with a higher prostaglandin $E_2$ content than degenerative lumbar disc disease. Sequestered discs tended to be associated with a higher prostaglandin $E_2$ content than extruded discs, which also showed higher prostaglandin $E_2$ content than protruded ones. A sciatica and positive straight leg raising test appeared to be associated with a higher prostaglandin $E_2$ content than a negative test. Conclusion : This result suggests that the level of prostaglandin $E_2$ would be correlated with clinical symptom and sign in the inflammatory process of lumbar disc herniation.

• Journal of Korean society of Dental Hygiene
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• v.18 no.1
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• pp.9-18
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• 2018

Objectives: Pleurotus eryngii is used both for edible and medicinal purposes, and has a physiological activity. The purpose of this study is to investigate the antibacterial effect of Pleurotus eryngii against six oral pathogens (Staphylococcus aureus, Streptococcus criceti, Streptococcus mutans, Streptococcus ratti, Streptococcus sobrinus, and Actinomyces viscosus). Methods: The antibacterial activities of various extracts of Pleurotus eryngii were examined by disc diffusion assay and minimum inhibitory concentration (MIC). The disc diffusion assay was performed by putting a paper disc soaked in extracts on plates inoculated bacterial cultures. The MIC of these extracts was determined by using a broth microdilution assay at a concentration ranging between 0.03 mg/ml to 15.00 mg/ml. The growth inhibition effect of extracts was measured at 600 nm for 24 hrs. Results: The antibacterial activity was confirmed against all six tested bacteria at Pleurotus eryngii ethyl acetate extract by the disc diffusion method. Acetone extract showed the antibacterial activity only against 4 strains containing Streptococcus criceti, Streptococcus mutans, Streptococcus ratti, and Actinomyces viscosus. In ethanol extract, no activity was observed against other strains except Staphylococcus aureus. MIC values of ethyl acetate extract were the same, 7.50 mg/ml in all tested bacteria. Conclusions: Pleurotus eryngii exhibited the antibacterial activity against oral pathogens (Staphylococcus aureus, Streptococcus criceti, Streptococcus mutans, Streptococcus ratti, Streptococcus sobrinus, and Actinomyces viscosus). Thus, Pleurotus eryngii may be considered as a natural antibacterial agent for treatment of dental diseases.

• The Korean Journal of Food And Nutrition
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• v.27 no.4
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• pp.609-618
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• 2014

We evaluated the yield of extract, antioxidant compounds (total phenolic, total flavonoid), antioxidant (DPPH assay, ABTS assay, Oyaizu's assay, FRAP assay), and antimicrobial activities of Siraegi (dried radish greens) according to cooking process (non-blanched, blanched, seasoned). The yield of non-blanched Siraegi was 4.91%, blanched Siraegi was 0.33%, and seasoned Siraegi was 7.55%. In total polyphenol and flavonoid contents, seasoned Siraegi extracts showed higher antioxidant compounds ($129.85{\pm}0.62mg$ GAE/100 g FW, $35.56{\pm}1.19mg$ CHE/100 g FW) than non-blanched and blanched. Total antioxidant activities (DPPH assay, ABTS assay, FRAP assay, reducing power) were shown to be in the order of seasoned Siraegi > non-blanched Siraegi > blanched Siraegi. In antimicrobial activity, non-blanched Siraegi (5, 10 mg/disc) showed antimicrobial activity against B. cereus, E. cloacae, and E. coli (9.25 mm), and P. aeruginosa (9 mm) at 10 mg/disc. In terms of antimicrobial activity, non-blanched Siraegi was good but eating the dried vegetable was difficult so it is essential to blanch it. Also, with many added seasonings in the process of cooking, it can be easy to eat. Overall, the results of this study demonstrate that cooked Siraegi with seasoning would be the most efficient way of ingesting the antioxidant material.

• The Korean Journal of Food And Nutrition
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• v.27 no.2
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• pp.147-155
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• 2014

This study is conducted to investigate the yield of extract, total phenolic compounds, total flavonoid compound contents, free radical scavenging activities (DPPH assay, ABTS assay), reducing power (Oyaizu's assay, FRAP assay) and antimicrobial activities of spinach according to various cooking methods (non-blanched, blanched, seasoned). The yield of non-blanched spinach is 1.64% and the extract yield of blanched spinach is 1.49%, and on the other hand, the yield of seasoned spinach is 6.01%. Total polyphenol contents of seasoned spinach is recorded as $124.31{\pm}1.37mg$ GAE/100 g FW, non-blanched spinach $51.24{\pm}0.27mg$ GAE/100 g FW, and blanched spinach $42.48{\pm}0.53mg$ GAE/100 g FW. From the total flavonoids, seasoned spinach extracts ($15.60{\pm}0.20mg$ CE/100 g FW) showed higher total flavonoid contents than non-blanched. Total antioxidant activities (DPPH assay, ABTS assay, FRAP assay, reducing power) are shown to be in the order of seasoned spinach > non-blanched spinach > blanched spinach. In the antimicrobial activities, non-blanched spinach (5, 10 mg/disc) showed antimicrobial activity against S. enterica and P. aeruginosa. The inhibition zone diameter from extracts of blanched spinach has not been detected. Seasoned spinach indicated antimicrobial activity only against P. aeruginosa (8.15 mm) at 10 mg/disc. If we are to eat a lot of non-blanched spinach, it would cause calculus. Blanching helps to prevent against calculus, since the blanching process can remove various amounts of oxalic acids. The overall results of this study demonstrate that seasoned cooked spinach would be the most efficient way of ingestion to consume antioxidant compounds.

• Korean Journal of Medicinal Crop Science
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• v.20 no.5
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• pp.308-314
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• 2012

This study was carried out to investigate the antibacterial activity against pathogens of acne and the anti-inflammatory effect of 75% ethanol extract and its fractions from the leaves of Prunus sargentii. In the antibacterial activity by the disc diffusion assay, the extract showed the highest effect against Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis in 5 mg/disc. However, the ethyl acetate fraction showed the highest antibacterial activity in 1 mg/disc. On the other hand, the hexane and chloroform fraction showed strong nitric oxide (NO) production inhibitory effect in lipopolysaccharide (LPS)-stimulated Raw 264.7 cell. In the cell viability of Raw 264.7 by MTT assay, the extract and all fractions were exhibited normal viabilities as nontoxic result. Consequently, the extract from the leaves of P. sargentii and its ethyl acetate fraction could be applicable to functional materials for antibacterial activity related fields. Moreover, the hexane and chloroform fraction could be applicable to candidate materials as anti-inflammatory agent.

• Natural Product Sciences
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• v.4 no.3
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• pp.130-135
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• 1998

The water extracts of 83 oriental herbal medicines (Hanbang) which have been clinically used to treat bacterial infections in Korea were screened for in vitro antibacterial activity by the paper disc assay method. Two Gram positive bacteria, Staphylococcus aureus SG 511, Bacillus subtilis ATCC 6633, and two Gram negative bacteria, Escherichia coli 055, Pseudomonas aeruginosa 9027 were used as test organisms. Among the extracts tested, MeOH extract of Baenongtang showed remarkably potent antibacterial activity. Activity-guided chromatographic fractionations of the $CH_2Cl_2$ extract of Baenongtang afforded seven antibacterial compounds.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1384-1391
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• 2006

The signal transduction system is one of the most important devices involved in maintaining life, and many protein kinases are included in the cellular signal transduction system. Finding a protein kinase inhibitor is very valuable, as it can be used to study cell biology and applied to pharmaceuticals. For the efficient and rapid screening of protein kinase inhibitors, two assay systems were combined; the nonradioactive protein kinase assay system that uses an FITC-labeled IRS-2 peptide and the cell-based paper disc assay system that uses Streptomyces griseus as the indicator strain. Among 330 kinds of herb extracts tested, the extract of Dalbergia odorifera exhibited the strongest inhibitory activity in the two assay systems and was selected for further isolation. Based on solvent extraction and many steps of chromatography, seven compounds were finally separated to homogeneity and their structures determined by $^{1}H$ and $^{13}C$ NMR spectroscopies. Four were to be flavonoids and identified as butin ($C_{15}H_{12}O_5$, Mw=272.07), 3'-hydroxymelanetin ($C_{16}H_{12}O_6$, Mw=300.06), liquiritigenin ($C_{15}H_{12}O_4$, Mw=256.07), and 2'-hydroxyformononetin ($C_{16}H_{12}O_{5}$, Mw=284.07). 3'-Hydroxymelanetin inhibited the phosphorylation of the GSK3 protein by Akt to 37% at a concentration of $10{\mu}g/ml$ and showed the strongest cytotoxicity ($ED_{50}<50{\mu}g/ml$) against the human cancer cell line HCT116. Under the same conditions, liquiritigenin also inhibited the phosphorylation of GSK3 by Akt to 26%, and its cytotoxicity against the HCT116 cell line was lower than $100{\mu}g/ml$.