• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2009년도 International Meeting of the Microbiological Society of Korea
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• pp.81-81
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• 2009

• 상하수도학회지
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• 제26권6호
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• pp.779-786
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• 2012

The degradation of 2-chlorophenol(2-CP) by various AOPs(Advanced Oxidation Processes) including the photo-Fenton process has been examined. In sole $Fe^{2+}$, UV or $H_2O_2$ process without combination, low removal efficiencies have been achieved. But the photo-Fenton process showed higher removal efficiency for degradation of 2-chlorophenol than those of other AOPs including the Fenton process and the UV processes. In the photo-Fenton process, the optimal experimental conditions of 2-chlorophenol degradation were obtained at pH 3 and the $Fe^{2+}/H_2O_2$molar ratio of 1. Also the 2-chlorophenol removal efficiency increased with decreasing of the initial 2-chlorophenol concentration. 3-chlorocatechol and chlorohydroquinone were identified as photo-Fenton reaction intermediates, and a degradation pathway of 2-chlorophenol in the aqueous phase during the photo-Fenton reaction was proposed.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1286-1289
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• 2013

• Journal of Ginseng Research
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• 제45권2호
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• pp.295-304
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• 2021

Background: Acute promyelocytic leukemia (APL) is a hematopoietic malignancy driven by promyelocytic leukemia-retinoic acid receptor A (PML-RARA) fusion gene. The therapeutic drugs currently used to treat APL have adverse effects. 20(S)-ginsenoside Rh2 (GRh2) is an anticancer medicine with high effectiveness and low toxicity. However, the underlying anticancer mechanisms of GRh2-induced PML-RARA degradation and apoptosis in human APL cell line (NB4 cells) remain unclear. Methods: Apoptosis-related indicators and PML-RARA expression were determined to investigate the effect of GRh2 on NB4 cells. Z-VAD-FMK, LY294002, and C 87, as inhibitors of caspase, and the phosphatidylinositol 3-kinase (PI3K) and tumor necrosis factor-α (TNF-α) pathways were used to clarify the relationship between GRh2-induced apoptosis and PML-RARA degradation. Results: GRh2 dose- and time-dependently decreased NB4 cell viability. GRh2-induced apoptosis, cell cycle arrest, and caspase3, caspase8, and caspase9 activation in NB4 cells after a 12-hour treatment. GRh2-induced apoptosis in NB4 cells was accompanied by massive production of reactive oxygen species, mitochondrial damage and upregulated Bax/Bcl-2 expression. GRh2 also induced PML/PML-RARA degradation, PML nuclear bodies formation, and activation of the downstream p53 pathway in NB4 cells. Z-VAD-FMK inhibited caspase activation and significantly reversed GRh2-induced apoptosis and PML-RARA degradation. GRh2 also upregulated TNF-α expression and inhibited Akt phosphorylation. LY294002, an inhibitor of the PI3K pathway, enhanced the antitumor effects of GRh2, and C 87, an inhibitor of the TNF-α pathway, reversed NB4 cell viability, and GRh2-mediated apoptosis in a caspase-8-dependent manner. Conclusion: GRh2 induced caspase-dependent PML-RARA degradation and apoptosis in NB4 cells via the Akt/Bax/caspase9 and TNF-α/caspase8 pathways.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.946-951
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• 2005

Biodegradation of the endocrine-disrupting chemical di-n-butyl phthalate (DBP) was investigated using a bacterium, Pseudomonas fluorescens B-1, isolated from mangrove sediment. The effects of temperature, pH, salinity, and oxygen availability on DBP degradation were studied. Degradation of DBP was monitored by solid-phase extraction using reversed-phase HPLC and UV detection. The major metabolites of DBP degradation were identified as mono-n-butyl phthalate and phthalic acid by gas chromatography-mass spectrometry (GC-MS) and a pathway of degradation was proposed. Degradation by P. fluorescens B-1 conformed to first-order kinetics. Degradation of DBP was also tested in seawater by inoculating P. fluorescens B-1, and complete degradation of an initial concentration of $100{\mu}g/l$ was achieved in 144 h. These results suggest that DBP is readily degraded by bacteria in natural environments.

• Parasites, Hosts and Diseases
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• 제44권2호
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• pp.127-131
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• 2006

The furcocercus cercariae of Neodiplostomum seoulense (Digenea: Neodiplostomidae) penetrate the skins of tadpoles and shed their tails. The speculated mechanism of this tail loss was physical efforts required to produce a vigorous zigzag motion during skin penetration; no other mechanism has been proposed. We examined the relationship between the host serum and cercarial tail loss. Cercariae of N. seoulense were collected from experimentally infected Segmentina hemisphaerula, and lots of 300 cercariae were cultured in medium 199 contained several types of sera. Cercarial tail degradation was induced in all media, but all the cercariae cultured except those cultured in media containing fetal bovine serum (FBS) died within 48 hr. After 72 hr cultivation in media containing FBS, cercarial tail degradation was induced in 67.0%; in continuous cultivation 13.3% of larvae survived for 7 days. Tail degradation did not occur in the absence of serum and when serum was heat inactivated at $56^{\circ}C$ for 30 min. The addition of 20 mM ethylenediaminetetraacetic acid (EDTA) blocked cercarial tail degradation completely. Moreover, the addition of 20 mM $MgCl_2$ restored tail degradation blocked by EDTA. These results suggest that the alternative complement pathway is related with the N. seoulense cercarial tail degradation induced by serum.

• 상하수도학회지
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• 제35권1호
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• pp.27-37
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• 2021

Tetracycline is one of the most commonly used as antibiotics for the livestock industry and it is still widely used nowadays. Tetracycline and its metabolites are excreted with excrement, which is difficult to completely removed with conventional sewage treatment, therefore it is apprehended that the tetracycline-resistant bacteria occurs. In this study, the oxidant named ferrate(VI) was used to degrade the tetracycline and investigate the reaction between ferrate(VI) and tetracycline under various aqueous conditions. The highest degradation efficiency of tetracycline occurred in basic condition (pH 10.1 ± 0.1) because of the pKa values of tetracycline and ferrate(VI). The results also showed the effect of water temperature on the degradation of tetracycline was not significant. In addition, the dosage of ferrate(VI) was higher, the degradation of tetracycline and the self-degradation of ferrate(VI) also higher, finally the efficiency of ferrate(VI) was lower. The results said that the various mechanisms effects the reaction of ferrate(VI) oxidation, it required the consideration of the characteristics of the target compound for optimal degradation efficiency. Additionally, intermediate products were detected with LC/MS/MS and three degradation pathways were proposed.

• Journal of Ginseng Research
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• 제44권1호
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• pp.123-134
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• 2020

Background: The lepidopteran Asiatic corn borer (ACB), Ostrinia furnacalis (Guenee), has caused huge economic losses throughout the Asian-Western Pacific region. Usually, chemical pesticides are used for the control, but excessive use of pesticides has caused great harm. Therefore, the inartificial ecotypic pesticides to ACB are extremely essential. In our previous study, we found that panaxadiol saponins (PDS) can effectively reduce the harm of ACB by causing antifeedant activity. Therefore, it is necessary to reveal the biological molecular changes in ACB and the functionary mechanism of PDS. Methods: We analyzed the global transcription of ACB with different PDS concentration treatment (5 mg/mL, 10 mg/mL, and 25 mg/mL) by high-throughput sequencing and de novo transcriptome assembly method. Results: PDS treatment could cause the changes of many gene expressions which regulate its signal pathways. The genes in peroxisome proliferator-activated receptor (PPAR) signaling pathway were significantly downregulated, and then, the downstream fatty acid degradation pathway had also been greatly affected. Conclusion: Through this experiment, we hypothesized that the occurrence of antifeedant action of ACB is because the PDS brought about the downregulation of FATP and FABP, the key regulators in the PPAR, and the downregulation of FATP and FABP exerts further effects on the expression of SCD-1, ACBP, LPL, SCP-X, and ACO, which leads to the disorder of PPAR signaling pathway and the fatty acid degradation pathway. Not only that, PDS treatment leads to enzyme activity decrease by inhibiting the expression of genes associated with catalytic activity, such as cytochrome P450 and other similar genes.

• 약학회지
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• 제31권5호
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• pp.280-285
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• 1987

There are three plausible bioconversion pathways in biodegradation mechanism of capsaicinoids; first, side chain degradation through $\omega$-hydroxylation and $\beta$-oxidation, secondly, aromatic ring hydroxylation, and lastly, hydrolysis on the acidaraide linkage. In microbes, it was reported that capsaicin and its synthetic, analog, nonoylvanillylamide(NVA), could be metabolized to N-vanillylcarbamoylbutyric acid via $\omega$-hydroxylation and consecutive $\beta$-oxidations by Aspergillus niger. In order to broaden the scope of microbial degradation of capsaicinoids, over thirty strains of various fungi including Aspergillus, Penicillum, Mycotypha, Gliocladium, Paecilomyces, Byssoclamys, Conidiobolus, Thamnidium, and Entomophthora. It was observed that almost all the strains examined oxidized, the side chain of capsaicids as A. niger did. These observations strongly support the notion that side chain degradation is the most dominant pathway in the microbial degradation of capsaicinoids.

• Applied Biological Chemistry
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• 제41권4호
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• pp.222-227
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• 1998

The activities of enzymes of carbohydrate metabolism have been determinated in the host cytosolic and bacteroid fractions of cowpea (Vigna unguiculata) nodules formed with B. japonicum I 16 and in roots of nodulated cowpeas. The host cytosolic fraction of the nodules contained the enzymes of glycolytic pathway and the pentose phosphate pathway, whereas the bacteroids had only limited capacity for carbohydrate metabolism and appeared to be insufficient for the complete glycolytic pathway as well as starch synthesis and degradation. In a time-course study, using plants grown in a glasshouse, the acetylene-reducing activity (ARA) of the nodules increased in parallel with the total N content of plants and protein of the nodules until approximately 8 weeks after planting. Subsequently, the weight and size of the nodules and the weight of the plants continued to increase, but there was a sharp decrease in the ARA and the total N content of the plants.