• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.767-773
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• 1990

The effect of storage conditions on the oxidative stability of cholesterol in butter was studied by quantifying cholesterol oxides by GC-MS. Experimental variables for storage conditions were packaging, storage temperature, light source, and storage period. No cholesterol oxides were detected from packaged butter under all storage conditions. When unpackaged butter was stored under ultraviolet light at ambient temperature, $7{\alpha}-hydroxycholesterol,\;7{\beta}-hydroxycholesterol$, cholesterol ${\beta}-epoxide$, cholesterol ${\alpha}-epoxide$, cholestane-triol were detected after 2, 4, 6 and 8 weeks of storage. The amounts of cholesterol oxide species produced were different depending on the storage periods. The amounts of each cholesterol oxides, $7{\alpha}-hydroxycholesterol,\;7{\beta}-hydroxycholesterol$, cholesterol ${\beta}-epoxide$, cholesterol ${\alpha}-epoxide$, and cholestane-triol, produced after 2 weeks of storage were 34.2, 14.0, 12.1, 1.30, and 0.50 ppm, respectively, and after 8 weeks of storage were 68.1, 29.1, 56,3, 8.50, and 4.00 ppm, respectively with trace amounts of 3,5-cholestadien-7-one. When fluorescent light was used instead of ultraviolet light with other conditions remained the same, the same species of cholesterol oxides were detected but with lesser amounts.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.2989-2992
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• 2009

An efficient synthetic route of novel 2′(${\alpha}$)-C-fluoro-2′(${\beta}$)-C-methyl carbocyclic nucleoside analogues is described. The key fluorinated intermediate 7 was prepared from the epoxide intermediate 5 via selective ring-opening of epoxide. Coupling of 7 with nucleosidic bases under the Mitsunobu reactions followed by deprotection afforded the target carbocyclic nucleoside analogues. The synthesized compounds were evaluated as inhibitors of the hepatitis C virus (HCV) in Huh-7 cell line in vitro.

• Bulletin of the Korean Chemical Society
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• v.20 no.5
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• pp.551-555
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• 1999

11-Deoxydaunomycinone 15 and 10-fluoroanthracyclinone derivatives 9, 10 were obtained. Naphthalenone 4 prepared from 2-(2,4-pentadienyl)-1,3-dioxane 2 with methyl vinyl ketone and hydrolysis with HClO4 was condensed with phthalidesulfone 5 through Michael type reaction, and was converted to 7 by epoxidation. Epoxide 7 was transformed to trione 12 using reduction-oxidation or hydrofluorination process, and then to 15 by introducing several functional groups. Compound 8 obtained in the course of the reaction of epoxide 7 and HF/ Pyr was used for the synthesis of compounds 9, 10.

• Korean Journal of Food Science and Technology
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• v.8 no.4
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• pp.219-224
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• 1976

The appearance of organochlorine pesticide residues in shellfish, seaweed, mud and water samples collected from south coast of Korean peninsula in September 1974 was surveyed to obtain the following results. 1) The residues in shellfish samples were found to be in the orders of Choongmoo > Yeosoo > Busan > Mokpo area, top-shell >short-necked clam > mussel > hard clam > red-shell, aldrin > ${\alpha}-BHC$ > heptachlor> ${\gamma}-BHC$ > dieldrin > heptachlor epoxide > endrin and in the range of $0-49\;{\mu}g/kg$ edible fresh muscle. 2) The residues in seaweed samples from Wando area were found to be in the orders of tangle > green laver > laver, ${\alpha}-BHC$ > ${\gamma}-BHC$ > aldrin > dieldrin > heptachlor > heptachlor epoxide > endrin and in the range of $0-60\;{\mu}g/kg$ dry matter. 3) The residues in water samples were found to be in the orders of Yeongsan River > Nakdong River > Seomjin River > Choongmoo shellfish farm, ${\alpha}-BHC$ > ${\gamma}-BHC$ > aldrin > heptachlor > dieldrin > heptachlor epoxide > endrin and in the range of $0-180\;{\mu}g/kl$ while those in mud samples were in the order of ${\alpha}-BHC$ > ${\gamma}-BHC$> aldrin > dieldrin > heptachlor > heptachlor epoxide > endrin and in the range of $0.7-18\;{\mu}g/kg$ dry matter. It should be noted that BHC contents of water samples from Yeongsan and Nakdong rivers were far above the recommended environmental levels in USA.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.129-135
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• 2006

A gene encoding for a putative microsomal epoxide hydrolase (mEH) of a zebrafish, Danio rerio, was cloned and characterized. The putative mEH protein of D. rerio exhibited sequence similarity with mammalian mEH and some other bacterial EHs. A structural model for the putative mEH was constructed using homology modeling based on the crystallographic templates, 1 qo7 and 1 ehy. The catalytic triad consisting of $Asp^{233}$, $Glu^{413}$, and $His^{440}$ was identified, and the characteristic features such as two tyrosine residues and oxyanion hole were found to be highly conserved. Based on bioinformatic analysis together with EH activity assay, the putative protein was annotated as mEH of D. rerio. Enantiopure styrene oxide with enantiopurity of 99%ee and yield of 33.5% was obtained from racemic styrene oxide by the enantioselective hydrolysis activity of recombinant mEH of D. rerio for 45 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1220-1225
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• 1999

Differences in carotenoid composition in the integument of Korean bittering, Cheilognathus signifer and bride bittering, Rhodeus ukekii which are Korean native fresh water fish were compared. Total ca rotenoid contents in the integument of wild Korean bittering was 2.11mg% and composed of 42.6% zeaxanthin, 12.1% diatoxanthin and 12.1% lutein epoxide which are predominant carotenoids and 10.3% cynthiaxanthin, 8.3% zeaxanthin epoxide, 6.4% lutein and 1.5% cryptoxanthin which are minor carotenoids. Total ca rotenoid contents in the integument of wild bride bittering was 4.99mg% during a spawning period but after the spawning period it was decreased to 4.17mg% and carotenoid composition of bride bittering during the spawning period was 46.7% zeaxanthin, 26.5% diatoxanthin and 12.3% lutein which are predominant carotenoids, and 6.2% zeaxanthin epoxide, 3.1% cynthiaxanthin, 2.9% cryptoxanthin and 0.7% canthax anthin which are minor carotenoids. These results indicated that the carotenoid composition of bride bittering during spawning period was very similar to that of Korean bittering and carotenoid composition of bride bittering after the spawning period was 30.5% diatoxanthin, 21.5% cynthiaxanthin and 16.8% zeaxanthin which are predominant carotenoids and 14.0% cryptoxanthin, 11.3% lutein and 3.4% can thaxanthin which are minor carotenoids, indicating that after the spawning period, the content of zeaxanthin was decreased while that of cryptoxanthin and cynthiaxanthin was increased as compared to that of the spawning period. Total carotenoid contents in Korean bittering and bride bittering was relatively higher than that in other species of cyprinidae whereas composition of the carotenoid was similar.

• Environmental Mutagens and Carcinogens
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• v.17 no.2
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• pp.97-108
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• 1997

The drugs or xenobiotics introduced to the body, are detoxified through the process of biotransformation in the body. In this process, most of the insoluble compounds become more polar, soluble and easily excretable. But, parts of introduced materials are metabolized to highly reactive electrophilic carcinogens through activation pathways. These metabolites are toxic and can react with DNA, RNA and proteins which are nucleophilic compounds. The objective of this study is to illustrate the aleactivation pathways of two highly reactive epoxide compounds, vinyl carbamate epoxide (VCO) and 2'-(4-nitrophenoxy)oxirane (NPO). They are the ultimate electrophilic carcinogens of ethyl carbamate(urethane) and 4-nitrophenyl vinyl ether, respectively. In this research, we studied the inhibition of the mutagenic activities of VCO or NPO by nuchieophiles [glutahione(GSH) and N-acetylcysteine(NAC)], detoxifying enzymes[epoxide hydrolase and glutathione-S-transferase(GST)] and intracellular organelles (microsomes and cytosol). In addition we also tested the suppression of DNA adducts formation by GSH and NAC. The results are summerized as follow. 1. The microsomes and cytosol which contain epoxide hydrolase and GST, respectively, decreased the mutagenicity of VCO (74% and 95%, respecfivel), and NPO (35% and 93%, respectively). The nucleophilic GSH and NAC decreased the mutagenicity by 86% (VCO) and 80% (NPO), 76% (VCO) and 40% (NPO), respectively. 2. The purified epoxide hydrolase decreased the mutagenicity of two epoxides in a dose-dependent manner, and GSH also decreased the mutagenicity in the presence of GST. 3. Formation of two DNA adducts, 7-(2'-oxoethyi)guanine (OEG) and N2,3-ethenoguanine(EG), were compared in the presence of calf thymus DNA and epoxide (VCO or NPO) in vitro system. The amounts of DNA adducts were decreased in the presence of GSH (25% and 29% in VCO, 32% and 29% in NPO), and NAC (14% and 16% in VCO, 21% and 11% in NPO), respectively. From these results, it is concluded that the ultimate carcinogenic metabolites, VCO and NPO, can be made in the body, but much of them may be inactivated and detoxified by the nucleophilic GSH, NAC and detoxifying enzymes (epoxide hydrolase and GST). Therefore, by these mechanism, the formation of DNA adducts and mutagenic activities of these two epoxides may be lowered in vivo.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1099-1106
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• 1999

Effects of dietary carotenoids were investigated on metabolism of the carotenoids, and body pigmen tation in oily bittering, Acheilognathus koreensis. Two weeks later after depletion,oily bitterings were fed the diets supplemented with either lutein, cynthiaxanthin and astaxathin for 4 weeks. Carotenoids distributed to and metabolized in integument were analyed. The carotenoid isolated from the integument of wild oily bittering, composed of 47.2% zeaxanthin, 11.4% lutein epoxide, 11.0% diatoxanthin, 9.7% lutein and 8.3% zeaxanthin epoxide. Meanwhile, two weeks later after depletion, the carotenoid composed of 29.9% crytoxanthin, 19.3% zeaxanthin, 13.2% lutein epoxide, 12.0% diatoxanthin and 8.8% zeaxanthin epoxide. These indicated that zeaxanthin, diatoxanthin, lutein epoxide and zeaxanthin epoxide were actively metabolized in oily bittering, compared to that of other fresh water fish. Total carotenoid content in the integument of wild oily bittering and oily bittering depleted for two weeks was found to be 1.72mg% and 2.08mg%, respectively. Two weeks later after treatment of experimental diet, total carotenoids content was increased to 2.23mg% in lutein, 2.36mg% in cynthiaxanthin and 2.49mg% in astaxanthin supplemented group, which were relatively higher than 2.10mg% in control group. Meanwhile, 4 weeks later, total ca rotenoids content was decreased to 1.76mg% in control, 1.95mg% in lutein, 1.74mg% in cynthiaxanthin and 1.72mg% in astaxanthin supplemented groups. These result indicate that dietary carotenoids were rapidly accumulated and then metabolized to certain metabolites shortly after feeding. Body pigmentation effects of the carotenoids due to accumulation of carotenoids in the integument of oily bittering was the most effectively shown in the astaxanthin supplemented group, followed by cynthiaxanthin and lutein supplemented groups. In the integument of oily bittering, dietary carotenoids were presumably biotrans formed via either oxidative or reductive pathways as presumed the variation of total carotenoid content and carotenoid composition in all experimental groups. The lutein was oxidized either to astaxanthin via doradexanthin and doradexanthin, or to zeaxanthin epoxide via zeaxanthin by oxidative pathway. Cynthiaxanthin was converted either to diatoxanthin and zeaxanthin by reductive pathway and then to zeaxanthin epoxide by oxidative pathway, or it was converted to astaxanthin via diatoxanthin, zeaxan thin and doradexanthin by oxidative pathway. Astaxanthin was converted to doradexanthin and zeaxanthin by reductive pathway and then to zeaxanthin epoxide by oxidative pathway. These results suggest that, oxidative pathway of carotenoids was major metabolic pathway along with reductive path way in fresh water fish.

• 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.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.435-438
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• 2003

Epoxide hydrolase(EH) catalyze the enantioselective hydrolysis of racemic epoxides to corresponding diols. A recombinant Pichia pastoris with EH from Rhodotorula glutinis has been constructed by reverse transcriptase-polymerase chain reaction(RT-PCR). The recombinant biocatalyst enantioselectively hydrolyze (R)-styrene oxide faster than (S)-enantiomer. The catalytic activity of recombinant biocatalyst was 7-fold higher than that of wild-type strain. The recombinant EH biocatalyst can be used for kinetic resolution for the production of enantiopure styrene oxide.