• Journal of the Korean Chemical Society
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• v.38 no.1
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• pp.13-20
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• 1994

Substituted anthrasemiquinone radical anions, which were formed by laser flash photoreduction of the substituted anthraquinone (1,4-DHAQ, 1,5-DHAQ, 1,8-DHAQ, 1,8-DCAQ), were studied by the electron spin resonance spectroscopy in the mixed solvents of the 2-propanol and the triethylamine. Hyperfine splitting constants (hfsc) were determined by simulating the ESR spectra. Extended Huckel Molecular Orbital (EHMO) calculations were performed to obtain $\pi$ spin densities for these quinones. The hyperfine splitting constants could be assigned to specific protons on the basis of $\pi$ spin densities.

• Korean Journal of Acupuncture
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• v.25 no.1
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• pp.113-130
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• 2008

Objectives : Hyangsapyungwisan (HPS) has been used for treatment of cardiovascular diseases including of arthralgia, myalgia in traditional Korean medicine. However, the medical actions of HPS have not been clearly investigated. The aim of this study was to elucidate the antiradical and antioxidant activity of the extract for herb-acupuncture (HPS-HA) obtained from HPS. Methods & Results : HPS-HA exhibited a stronger inhibition rate (55.5%) on lipid peroxidation of rat liver homogenate induced by $FeCl_2$-ascorbic acid. In addition, HPS-HA markedly interfered with hydroxylradical generation through iron ions chelating action. While pro-oxidant effect of HPS-HA was nearly undetectable at concentrations of 0.5-10㎎/mL. Moerover, HPS-HA revealed a potent antiradical activities on 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radicals, superoxide anions, nitric oxide and peroxynitrite. Furthermore, HPS-HA inhibited copper- and AAPH-mediated oxidation of human low-density lipoprotein (LDL), and also suppressed the relative electrophoretic mobility of LDL. HPS-HA showed strong protective activity against oxidative damage of HUVECs induced by SIN-1. Conclusions : These results suggest that HPS-HA may be effective in protecting against oxidative diseases.

• The Korea Journal of Herbology
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• v.23 no.2
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• pp.179-192
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• 2008

Objectives : Draconis Resina (DR) has been used as a traditional Korean herbal medicine since ancient times, and today it is used as a medication for wounds, tumors, diarrhea, rheumatism, in the itching of insect bites and with other conditions in the folk medicine. The aim of this study was to determine whether fractionated extracts of DR inhibit free radical generation, intracellular oxidation, production of nitrite, an index of NO, PGE2, iNOS, COX-2 and proinflammatory cytokines in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, Methods : DR extract prepared with methanol, and then fractionated with hexane, dichloromethane, ethylacetate, n-butanol and water. Inhibitory effect of DR onto free radical generation was determined by measuring DPPH, superoxide anions and nitric oxide scavenging activities in vitro. Cytotoxic activity of extracts on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. Intracelluar oxidation was analysed by DCF-DA assay. The nitric oxide (NO) production was measured by Griess reagent system. The levels of iNOS and COX-2 expression were confirmed by western blot. And proinflammatory cytokines were measured by ELISA kit. Results : Our results indicated that fractionated extracts, especially dichloromethane and ethyl acetate extracts, significantly inhibited free radical generation, the LPS-induced H202, NO, PGE2 production and iNOS, COX-2 expression accompanied by an attenuation of TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 formation in macrophages. Conclusions : Our results indicate that dichloromethane and ethyl acetate extracts of DR have potential as an agent of chronic inflammatory diseases.

• Polymer(Korea)
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• v.25 no.5
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• pp.736-743
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• 2001

An electro- active polymer (EAP) (poly(2-acrylamido-2- methyl propane sulfonic acid), PAMPS) gel crosslinked with N,N-methylenebisacrylamide (MBAA) has been prepared by free radical polymerization in aqueous solution with potassium persulfate as initiator PAMPS gel was swollen in surfactant solution to substitute surfactant for using as actuator. PAMPS gel showed a large movement in the surfactant solution by electric field. PAMPS gel showed the reversible binding and fast response rate. Bending mechanism of gel is related to the cooperative process of hydrophobic interaction, swelling-deswelling of gel and the electrostatic attraction between anode (+) and the anions of PAMPS gel. The response rate of PAMPS gel was increased as the applied potential and the degree of cross-linkage were increased. The response rate was increased as the bending cycle was repeated, but it was decreased with increasing the gel thickness.

• The Korea Journal of Herbology
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• v.22 no.1
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• pp.53-61
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• 2007

Objectives: Our previous studies have clearly demonstrated that the scavenging activity of reactive oxygen species (ROS), protective effect of lipid peroxidation (LPO), and inhibition of cytochrome P450 isozymes (CYPs) from the Circium japonicum aqua-acupuncture solution (CJAS). But, Circium japonicum water extracted solution (CJWS) was weakly reported in cardiovascular diseases such as oxidative stress-mediated atherosclerosis or its value evaluated. Methods: CJWS was assessed to determine the mechanism of its scavenging activity of ROS and inhibitory effect of CYP 2E1. Results: CJWS exhibited a concentration-dependent scavenger of DPPH and superoxide anions radicals using different assay systems. In addition, CJWS showed dose-dependent free radical scavenging activity, including hydroxyl radicals, peroxynitrite, and nitric oxide. The CJWS was also found to be effective in protecting rat liver homogenate against LPO. Futhermore, the CJWS showed significant inhibition of CYP 2E1 induced by pyrazol in a rat liver microsome. Conclusion : ROS and CYPs may play a role in several diseases, such as cardiovascular disease and heart failure. Our study demonstrated that the CJWS has excellent scavenging activity of ROS. Hence, it is worthwhile to investigate the potential effectiveness of CJWS in preventing oxidative stress-mediated cardiovascular diseases.

• BMB Reports
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• v.36 no.4
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• pp.337-343
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• 2003

Rhus verniciflua Stokes (RVS) has been used as a traditional herbal medicine. Several earlier studies indicated that an ethanol extract of RVS has both anti-oxidant and anti-tumor properties, although the mechanism for the activity remains to be elucidated. In this report, we prepared a highly purified ethanol extract from RVS, named REEE-1 ($\underline{R}$hus $\underline{e}$thanol $\underline{e}$luted $\underline{e}$xtract-1), and investigated the mechanism involved in its growth-inhibitory effect on the human B and T lymphoma cell lines, BJAB and Jurkat, respectively. Results from tritium uptake proliferation assays showed that the proliferative capacities of both BJAB and Jurkat cells were strongly suppressed in the presence of REEE-1. This was further confirmed through trypan blue exclusion experiments that revealed a dose-dependent decrease in viable cell numbers after REEE-1 treatment. REEE-1-mediated suppression of cell growth was verified to be apoptotic, based on the increase in DNA fragmentation, low fluorescence intensity in nuclei after propidium iodide staining, and the appearance of DNA laddering. In particular, REEE-1 exerted its anti-oxidant activity through the inhibition of hydroxyl radical-mediated degradation by iron ion chelation rather than direct scavenging of hydroxyl radicals. Furthermore, REEE-1 was revealed to be a potential scavenger of superoxide anions. Collectively, our findings suggest that REEE-1 is a natural anti-oxidant that could be used as a cancer chemo-preventive and therapeutic agent.

• Macromolecular Research
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• v.13 no.1
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• pp.45-53
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• 2005

In this study, a series of highly swelling hydrogels based on sodium alginate (NaAlg) and polymethacryl­amide (PMAM) was prepared through free radical polymerization. The graft copolymerization reaction was performed in a homogeneous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N'-methylenebis­acrylamide (MBA) as a crosslinker. The crosslinked graft copolymer, alginate-graft-polymethacrylamide (Alg-g­PMAM), was then partially hydrolyzed by NaOH solution to yield a hydrogel, hydrolyzed alginate-graft-poly­methacrylamide (H-Alg-g-PMAM). During alkaline hydrolysis, the carboxamide groups of Alg-g-PMAM were converted into hydrophilic carboxylate anions. Either the Alg-g-PMAM or the H-Alg-g-PMAM was characterized by FTIR spectroscopy. The effects of the grafting variables (i.e., concentration of MBA, MAM, and APS) and the alkaline hydrolysis conditions (i.e., NaOH concentration, hydrolysis time, and temperature) were optimized systematically to achieve a hydrogel having the maximum swelling capacity. Measurements of the absorbency in various aqueous salt solutions indicated that the swelling capacity decreased upon increasing the ionic strength of the swelling medium. This behavior could be attributed to a charge screening effect for monovalent cations, as well as ionic cross-linking for multivalent cations. Because of the high swelling capacity in salt solutions, however, the hydrogels might be considered as anti-salt superabsorbents. The swelling behavior of the superabsorbing hydrogels was also measured in solutions having values of pH ranging from 1 to 13. Furthermore, the pH reversibility and on/off switching behavior, measured at pH 2.0 and 8.0, suggested that the synthesized hydrogels were excellent candidates for the controlled delivery of bioactive agents. Finally, we performed preliminary investigations of the swelling kinetics of the synthesized hydrogels at various particle sizes.

• The Korea Journal of Herbology
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• v.24 no.3
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• pp.39-50
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• 2009

Objectives : Smilacis glabrae rhizoma (SG) has been traditionally used as a herbal medication of musculoskeletal disorders like arthritis, pain, convulsions, and syphilis in traditional Korean medicine. This study was investigated anti-oxidative and anti-inflammatory effect of fractionated extracts of Smilacis Glabrae Rhizoma in Human Umbilical Vein Endothelial Cell (HUVEC). Methods : SG extract prepared with methanol, and then fractionated with hexane, dichloromethane, ethylacetate, n-butanol and water. Inhibitory effect of SG onto free radical generation was determined by measuring DPPH, superoxide anions and nitric oxide scavenging activities in vitro. Cytotoxic activity of extracts on RAW 264.7 cells was measured using 5-(3-caroboxymethoxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. Intracelluar oxidation was analysed by DCF-DA assay. The nitric oxide (NO) production was measured by Griess reagent system. The levels of ICAM-1 and VCAM-1 expression were confirmed by western blot. And proinflammatory cytokines were measured by ELISA kit. Results : Our results indicated that fractionated extracts, especially ethyl acetate (EA) extract, significantly inhibited free radical generation, the TNF-$\alpha$-induced intracellular oxidation. Furthermore, the EA extract protected TNF-$\alpha$-induced adhesion to THP-1, expression of adhesion molecules accompanied by an attenuation of IL-6 and IL-8 formation in HUVEC. Conclusions : These results indicate that EA extract of SG have potential as an agent of atherosclerosis and other chronic inflammatory diseases including diabetes, hypertension, and arthritis.

• Journal of Life Science
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• v.19 no.4
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• pp.429-435
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• 2009

Oxidative stress is a consequence of an imbalance of the defense system against cellular damage generated by reactive oxygen species (ROSs) such as superoxide anions (menadione; MD). Most organisms have evolved a variety of defense systems to protect cells from adverse conditions. In order to evaluate stress tolerance against oxidative stress generating MD, comparative analyses of antioxidant capacity, or free radical scavenger ability, were performed between S. cerevisiae KNU5377 (KNU5377) and three wild-type S. cerevisiae strains. In a medium containing 0.4 mM MD, the KNU5377 strain showed higher cell viability and antioxidant ability, and contained higher levels of trehalose, superoxide dismutase, thioredoxin system, glucose-6-phosphate dehydrogenase, and some heat shock proteins. The KNU5377 strain also produced a lower level of oxidative stress biomarker than the other three yeast strains. These results indicate that S. cerevisiae KNU5377 has a higher level of tolerance to oxidative stress due to the increased expression of cell rescue proteins and molecules, thus alleviating cellular damage more efficiently than other S. cerevisiae strains.

• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.490-497
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• 1990

Two synthetic routes for the 1,4-diboracyclohexene-2 ring 8 have been developed. Method i) starts with 1,2-bis(dichloroaluminyl)ethane, in which the AlCl$_2$ group is replaced by BCl$_2$. Exchange of the chlorine with BI$_3$ in 1,2-bis-(dichloroboryl)ethane yields the corresponding iodo compound, which reacts with the alkynes to heterocycles 8a, b in good yield. In method ii) B$_2$Cl$_4$ is added to alkenes, replacement of chlorine with BI$_3$ yields the bis(diiodoboryl)ethane derivatives which undergo redox reactions with alkynes to give 8c, d. The diiodo derivative 8a forms the pyridine adduct 9a, and reacts with ether to give the ethoxy derivative 8f. 8a-d react with AlMe$_3$ to yield the corresponding dimethyl derivatives 8g-j, which give unstable radical anions when treated with potassium in THF. The ESR parameters are reported. In electrochemical experiments irreversible reductions of 8g-j are observed. 8g-j react with (C$_5$H$_5$)Co(C$_2$H$_4$)$_2$ to give the intermediate 16 VE complexes (C$_5$H$_5$)Co(8), in which C-H activation occurs with formation of the corresponding red 1,4-diboracyclohexadiene complexes 10. The X-ray structure analyses of 10h and 10j are reported.