• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2381-2386
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• 2009

The tetrakis(thio)-substituted-1,4-benzoquinone products 4a-e, 6, 7, and the mono(alkoxy)-tris(thio)-substituted-1,4- benzoquinone products 5a-e and 8a-e were synthesized from the reactions of p-chloranil with some thiols and mixture of two different thiol compounds in alcohol in the presence of $Na_2CO_3$ at room temperature. The structures of the novel S,S,S,S- and S,S,S,O- substituted products, which were obtained by the reactions of p-chloranil as a starting compound with n-propanethiol, n-pentanethiol, n-decanethiol, n-dodecanethiol, 2-methyl-2-propanethiol, and mixture of n-decanethiol and n-cyclohexanethiol as S-nucleophiles, were characterized by spectroscopic methods.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.122-124
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• 1999

Induction of NAD(P)H : (quinone-acceptor) oxidoreductase (QR) which obligatory two electron reduction of quinones and prevents their participation in oxidative cycling and thereby the depletion of intracellular glutathione, has been used as a marker for chemopreventive agents. We postulated that vitamin E, an antioxidant, which induces QR as the gene of QR was reported to contain antioxidant reponsive element in the 5'-flanking region. Vitamin E resulted in significant induction of QR in both hepalclc7 cells and mouse tissues. QR induction was observed; to be maximal at 25uM vitamin E for hepalclc7 cells while it was maximal in the level of 2.5∼5 μmoles vitamin E/㎏ BW for mouse tissues. Thus the cancer-preventive effect of vitamin E may be exerted by it induction of intracellular detoxifying enzymes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.3
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• pp.459-465
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• 1995

The ether extract of Salviae miltiorrhizae Radix(SMR) was fractioned to give five subfractions, so that two subfractions of them were recrystallized to yield each pure diterpene quinone pigment. On the basis of spectral evidence, these two compounds were identified as tanshinone II and crytotanshinone. Cryptotanshinone exhibited both of a potent platelet anti-aggregating activity in vitro and a potent antimicrobial activity. GC-MS analysis of the other extract showed that tanshinone II was contained in the largest proportion of all the diterpene quinones. In addition, GC-MS analysis gave other valuable analytical informations.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.47-58
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• 2003

Fibrosstatins, which were isolated from the culture broth of Streptomyces catanulae subsp. griseospora, are naphthoquinones which can work as alkylating agents. It is important to synthesize these quinone compounds for the study of their biological activities. In this paper, an efficient method, Hooker oxidation, to control the regiochemistry in the synthesis of fibrostatin B is reported.

• Bulletin of the Korean Chemical Society
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• v.12 no.6
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• pp.612-617
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• 1991

The approximate rates and stoichiometry of the reaction of excess 1,3,2-biphenyldioxaborepin [2,2'-biphenoxyborane (BPB)] with selected organic compounds containing representative functional groups under the standardized conditions (tetrahydrofuran, hydride to compound being 4 : 1, room temperature) was examined in order to define the characteristics of the reagent for selective reductions and compare its reducing power with those of other substituted boranes. The results indicate that BPB is unique and the reducing power is much stronger than that of other dialkoxyboranes, such as catecholborane and di-s-butoxyborane. BPB reduces aldehydes, ketones, quinones, lactones, tertiary amides, and sulfoxides readily. Carboxylic acids, anhydrides, esters, and nitriles are also reduced slowly. However, the reactions of acid chlorides, epoxides, primary amides, nitro compounds, and disulfides with this reagent proceed only sluggishly.

• Bulletin of the Korean Chemical Society
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• v.12 no.6
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• pp.644-649
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• 1991

The approximate rates and stoichiometry of the reaction of excess lithium tris(dibutylamino)aluminum hydride (LT-DBA) with selected organic compounds containing representative functional groups under standardized conditions (tetrahydrofuran, $0^{\circ}C$) were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The reducing ability of LTDBA was also compared with those of the parent lithium aluminum hydride and the alkoxy derivatives. The reagent appears to be much milder than the parent reagent, but stronger than lithium tri-t-butoxyaluminohydride in reducing strength. LTDBA shows a unique reducing characteristics. Thus, the reagent reduces aldehydes, ketones, esters, acid chlorides, epoxides, and amides readily. In addition to that, ${\alpha},{\beta}$-unsaturated aldehyde is reduced to ${\alpha},{\beta}$-unsaturated alcohol. Quinones are reduced to the corresponding diols without evolution of hydrogen. Tertiary amides and aromatic nitriles are converted to aldehydes with a limiting amount of LTDBA. Finally, disulfides and sulfoxides are readily reduced to thiols and sulfides, respectively, without hydrogen evolution.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.182.2-182.2
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• 2003

The abnormal proliferation and migration of vascular smooth muscle cell (SMC) play an important role in the pathology of coronary artery atherosclerosis and restenosis. Platelet-derived growth factor (PDGF) is one of the most potent promoters of the proliferation and migration of the SMC. The heterocyclic quinones represent an important class of biologically active molecules. However, the inhibitory activity of quinone classes on the proliferation of the SMC has not been reported. (omitted)

• Journal of Korean Society of Environmental Engineers
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• v.33 no.6
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• pp.396-404
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• 2011

An investigation on the removals of PAH-quinone compounds, which are commonly produced from the biological and/or chemical treatments of PAH-contaminated soils, from the aqueous phase via birnessite (${\delta}-MnO_2$)-mediated oxidative transformation is described. It was demonstrated that acenaphthenequinone (APQ), p-PAH quinone can be removed via birnessite-mediated oxidative-coupling reactions, and anthraquinone (AQ) and 1,4-naphthoquinone (1,4-NPQ), o-PAH quinones were efficiently removed by birnessite-mediated cross-coupling reactions in the presence of catechol (CAT) as a reactive mediator. The removals of PAH-quinone compounds followed pseudo-first-order reactions, and the rate constant (k, $hr^{-1}$) for the removals of 1,4-NPQ under the experiment conditions (1,4-NPQ = 10 mg/L, CAT = 50 mg/L, ${\delta}-MnO_2$ = 1.0 g/L, pH 5, Reaction time = 6~96 hr) was 0.0426, which was about 4 times lower than that of APQ (0.173). With the observed pseudo-first order rate constants with respect to birnessite loadings under the same experimental conditions, the surface-normalized specific rate constant, $K_{surf}$, for 1,4-NPQ was determined to be $8.5{\times}10^{-4}L/m^2{\cdot}hr$. The analysis of the kinetic data with respect to birnessite loading indicated that the cross-coupling reactions of 1,4-NPQ consist of two different reaction steps over time and the results have also been discussed in terms of the reaction mechanisms.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.216-222
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• 2016

BACKGROUND: Polychlorinated biphenyls (PCBs) are one of the most common environmental contaminants. Because of their recalcitrant properties and long-term toxicity, numerous studies have been performed. The toxicological concerns are focused on endocrinological effects of animal. Several different metabolites have been reported, including hydroxy PCBs, PCB quinones, and methylsulfonyl PCBs from animal tissues. However, details in plants have never been studied. It is well-known that plants can produce phytoalexin in response to chemical, physical, or pathological stress.METHODS AND RESULTS: In this study, the several PCBs and hydroxy derivatives were prepared by chemical syntheses. Their effects on secondary metabolite biosynthesis were determined in carrot roots. The levels of 6-methoxymellein were determined in several different treatments, using gas chromatography-mass spectrometry. In general, the concentration of 6-methoxymellein reached a maximum at 2 days and gradually decreased to trace level at 5 days in control experiments. However, the effects of PCBs or hydroxy derivatives were highly dependent on compounds. For example, the maximum concentrations of 6-methoxymellein were observed at 3 days for 2-hydroxy/4-hydroxybiphenyl, while 3,3',4,4',5-pentachlorobiphenyl and 3,5-dichloro-2-hydroxybiphenyl showed a rapid accumulation within 1 day, followed by rapid dissipation to undetectable levels.CONCLUSION: Biphenyl derivatives were effective elicitor of 6-methoxymellein accumulation. In general, hydroxybiphenyls (phenols) more efficiently induced phytoalexin biosynthesis than those without hydroxy groups. It can be concluded that PCBs or their possible metabolites could change the plant secondary metabolism.

• Journal of the Korean Chemical Society
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• v.64 no.1
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• pp.7-18
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• 2020

An efficient and facile procedure has been developed for the synthesis of novel bichalcone derivatives (4a, 4b). The key step contains the solvent-free aldol synthesis of bichalcones based on quinones. Bichalcones (4a, 4b) were used as precursors for the synthesis of some interesting heterocyclic compounds like, diazepines (5a, 5b), pyrazolo-pyrimidines (7a, 7b), and pyrazoline derivatives (8a, 8b). Moreover, new thioxopyrimidine derivatives (9a, 9b) were furnished and used as a functionalizing agent to produce the triazole-pyrimidines (11, 12) and the carbonitrile derivative (14). All the synthesized compounds were fully characterized using physical and spectral data like, FT-IR, ¹H NMR, ¹³C NMR, and MS. Bichalcones (4a, 4b) and diazepines (5a, 5b) were screened for their anticonvulsant activity, where compounds (4a, 5a, and 5b) revealed potent anticonvulsant activity compared to diazepam. On the other hand, some of the prepared compounds were screened for their antiproliferative activity and they showed significant cytotoxic effects on most of the cancer cell lines with regard to broad spectrum antitumor activity.