• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.65.2-65.2
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• 2007

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• Journal of Life Science
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• v.15 no.5 s.72
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• pp.779-782
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• 2005

Cell-free expression is a powerful tool for rapid protein analysis, enabling an efficient identification of gene without cumbersome procedure of transformation and cell culture. Epoxide hydrolase (EH) gene of Rhodotorula glutinis was simply amplified by PCR, and the resultant gene was expressed in vitro using a coupled Transcription/translation system. The cell-free expressed EH protein mixture exhibited the enantioselective hydrolysis activity toward (R)-styrene oxide, representing that cell-free protein synthesis system can be used for the rapid expression of an enantioselective enzyme for an efficient identification of the chiral activity.

• Journal of Life Science
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• v.12 no.4
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• pp.423-426
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• 2002

Enantioselective resolution of racemic para-nitrostyrene oxide was investigated using epoxide hydrolase activity of Aspergillus niger LK for the production of optically pure (S)-para-nitrostyrene oxide. To overcome the poor solubility of the substrate, enantioselective hydrolysis in an organic solvent was attempted under optimized reaction conditions including reaction temperature and water content. (S)-para-Nitrostyrene oxide with high optical purity (> 99% ee) was obtained at 37% yield using fungal epoxide hydrolase-catalyzed enantioselective resolution.

• Journal of Life Science
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• v.13 no.1
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• pp.105-109
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• 2003

Epoxide hydrolase (EH) gene from Aspergillus niger #33 was cloned from cDNA library generated by reverse transcriptase-polymerase chain reaction (RT-PCR). The nucleotide sequence analysis revealed that the deduced amino acid sequence was almost similiar to that of A. niger LCP521 previously reported. The cloned EH gene was transformed into Saccharomyces cerevisiae and expressed by addition of galactose. The recombinant S. cerevisiae showed hydrolytic activity toward racemic phenyl oxirane substrate based on chiral GC analysis, and can be used as a potential biocatalyst for the preparation of chiral phenyl oxirane.

• Toxicological Research
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• v.11 no.2
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• pp.329-335
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• 1995

Incubation of aflatoxin $B_1$ $(AFB_1)$ with microsomes isolated from human liver number 110 yielded two metabolite peaks which were aflatoxin $Q_1$ $(AFQ_1)$ and $(AFB_1)$-exo-8, 9-epoxide (exo-epoxide) in high performance liquid chromatography. Production ratio of $AFQ_1$ to exo-epoxide was 2.43$\pm $0.04. Metabolism of $(AFB_1)$ to $(AFQ_1)$ and exo-epoxide was inhibited by troleandomycin in a same degree although troleandomycin was not activated as a mechanism-based inhibitor. The inhibitory effect was dependent upon either the incubation time with $(AFB_1)$ or the preincubation time before the addition of $(AFB_1)$. Incubation of troleandomycin and NADPH by the microsomes resulted in the formation of a cytochrome P 450 (P450)-metabollc intermediate (MI) complex and the level was approximately 80% of total P450 3A4 in the microsomes. This figure was similar to that of the inhibitory effect of troleandomycin on $AFB_1$ metabolism. Glutathione which was reported that it prevented the formation of MI complex in rat liver microsomes did not inhibit the formation of MI complex in human liver microsomes. These results suggested that the inhibitory effect of troleandomycin on $AFB_1$ metabolism is due to the formation of MI complex with P450 3A4. And the reaction mechanism of troleandomycin by human liver microsomes might be dlfferent from that one by rat liver microsomes.

• The Journal of Internal Korean Medicine
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• v.21 no.1
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• pp.108-115
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• 2000

Objective : To investigate the hepatoprotective effects of Gami-oryungsan on the liver damage induced by bromobenzene. Method : The development of fibrosis and acute liver injury was examined by the chemical analysis of AST, AL T, ${\gamma}$-GTP . and epoxide hydrolase glutathione S-transferase glutathione peroxidase enzyme activity, lipidoperoxide levels, glutathione levels were measured and oberved. Results : The increasing levels of lipidoperoxide was decreased proportionally according to dose of extract GO. Epoxide hydrolase glutathioneS-transferase glutathione peroxidase enzyme activity highly increased in GO pre-acupunctured group compared with the group treated with only bromobenzene. The increase of serum AST, AL T, ${\gamma}$-GTP enzyme activity of mice by bromobenzene was inhibited by the administration of GO. Lipidoperoxide levels in rat's liver decreased compared to the case of bromobenzene-treated group. The levels of Glutathione decreased by bromo benzene were increased highly in GO pre-acupunctured group. Conclusion : These results suggest that GO extract recovers the damage of liver due to bromobenzene intoxication by decreasing the lipid peroxidation AST AL T ${\gamma}$-GTP enzyme activity and increasing epoxide hydrolase glutathioneS-transferase glutathione peroxidase enzyme activity, glutathione levels.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.950-957
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• 1995

The carotenoids of 14 Korean Citrus were analyzed by HPLC and spectrophotometry. Selected Citrus varieties were Satsuma mandarins, Orange, Ponkan, Marumeru and Iyeagam. The amount of carotenoid in peel and juice of Citrus is $0.82{\sim}10.64\;mg%$ and $0.23{\sim}3.38\;mg%$, respectively. Among the 14 peaks obtained from each samples, ${\alpha}-carotene$, ${\beta}-carotene$, Iycopene and lutein were identified by the direct comparison with authentics. Eigth peaks were assumed to neoxanthin, violaxanthin, antheraxanthin, lutein-5,6-epoxide, isolutein, cryptox-diepoxide, cryptox-5,6-epoxide and ${\beta}-cryptoxanthin$ through reference $t_R$ and two peaks remained unknown.

• Journal of the Korean Chemical Society
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• v.32 no.6
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• pp.575-580
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• 1988

$({\pm})-{\gamma}$-Rhodomycinone(4) and 10-Deoxy-${\gamma}$-rhodomycinone(5), late-stage Precursors of the alglycone of antitumor antibiotic Rhodomycin(2) were prepared from the cleavage of epoxide ring of 9-ethyl-9,10-epoxy-4,6, 11-trihydroxy-7,8,9,10-tetrahydronaphthacene-5,12-dione(10). The epoxide 10 was furnished from 9-acetyl-4,5,6,11,12-pentamethoxy-7,8-dihydronaphthacene(6), which was assembled utilizing ring annelation methodology developed by Hauser-Rhee.

• Carbon letters
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• v.16 no.2
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• pp.116-120
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• 2015

We investigated the adsorption of Na on graphene and graphene oxide, which are used as anode materials in sodium ion batteries, using density functional theory. The adsorption energy for Na on graphene was -0.507 eV at the hollow sites, implying that adsorption was favorable. In the case of graphene oxide, Na atoms were separately adsorbed on the epoxide and hydroxyl functional groups. The adsorption of Na on graphene oxide-epoxide (adsorption energy of -1.024 eV) was found to be stronger than the adsorption of Na on pristine graphene. However, the adsorption of Na on graphene oxide-hydroxyl resulted in the generation of NaOH as a by-product. Using density of states (DOS) calculations, we found that the DOS of the Na-adsorbed graphene was shifted down more than that of the Na-adsorbed graphene oxide-epoxide. In addition, the intensity of the DOS around the Fermi level for the Na-adsorbed graphene was higher than that for the Na-adsorbed graphene oxide-epoxide.

• Journal of Preventive Medicine and Public Health
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• v.43 no.1
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• pp.1-8
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• 2010

Objectives: This study was performed to investigate if organochlorine pesticides (OCPs) were associated with metabolic syndrome and insulin resistance among non-diabetes. Methods: Among subjects who participated in a community-based health survey, 50 non-diabetic subjects with metabolic syndrome and 50 normal controls were selected. Insulin resistance was measured by the homeostasis model assessment (HOMA-IR). Eight OCPs were selected. Results: After adjusting for confounders except for body mass index (BMI), beta-hexachlorocyclohexane ($\beta$-HCH) and heptachlor epoxide were positively associated with metabolic syndrome. Odds ratios across tertiles of $\beta$-HCH and heptachlor epoxide were 1.0, 3.2 and 4.4, and 1.0, 4.0 and 6.0, respectively (p for trend = 0.01 and <0.01). After additional adjustment for body mass index (BMI), heptachlor epoxide still showed an increasing trend with adjusted odds ratios of 1.0, 4.1, and 4.6 (p for trend = 0.10). When the five components of metabolic syndrome (with the definition of high fasting glucose ($\geq$ 100 mg/dL) were separately analyzed, all components were positively, but not significantly, associated with heptachlor epoxide. As the serum concentration of heptachlor epoxide increased, HOMA-IR increased significantly in subjects with metabolic syndrome even after adjusting for BMI (p value <0.05 and <0.01). Conclusions: Despite the small sample size, this study suggests that the background exposure to some OCPs may be associated with metabolic syndrome.