• Fisheries and Aquatic Sciences
• /
• v.9 no.4
• /
• pp.175-178
• /
• 2006

An acidic ent-cyclic peroxide was isolated from a sponge, Plakotis sp., and showed activity against leishmaniasis and pathogenic fungi. To improve the activity of this compound, we coupled the acidic ent-cyclic at the C1 position of ircinol A. Compound 3 exhibited significant activity against Leishmania mexican a and fungi with $IC_{50}$ values of 0.7 and $0.3-34{\mu}g/mL$, respectively. The yield of compound 3 was 98%.

• Journal of the Korean Applied Science and Technology
• /
• v.27 no.4
• /
• pp.531-538
• /
• 2010

The electrochemistry characterization of metal is important in many industrial applications. In this study, we investigated the C-V diagrams related to the electrochemistry characterization of nickel. We determined electrochemical measurement by using cyclic voltammetry with a three electrode system. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650mV and measured to the initial point. The scan rate were 100, 150, 200 and 200mV/s. As a result, the C-V characterization of nickel using ethanolamine and ethylethanolamine inhibitor appeared irreversible process caused by the oxidation current from the cyclic voltammogram. After adding ethanolamine compound additive, adsorption film constituted, and the passive phenomena happened. According to the results by cyclic voltammetry method, it was revealed that the effect of the electrochemistry characterization of nickel depends on ethanolamine structure interaction to adsorption complex.

• Journal of Environmental Science International
• /
• v.11 no.2
• /
• pp.131-137
• /
• 2002

The chemical behavior and properties on the redox state of environmental pollutant has been investigated by electrochemical methods. We carried out to measure the variations in the redox reaction of differential pulse polarogram and cyclic voltammogram. The results observed the influences on redox potential and current of various factors with temperature and pH. These were established factors as the effect of the redox reaction. It can be clearly recognized that the electrode reaction are from qusi-reversible to irreversible processes. Also, it was mixing with reaction current controlled. The bits-phenol A in the waste water was made to compound with cobalt ion and it take away from the separation into compound. The $Co(BPA)_2$ compound was not found to be dissociation in waste water. However, this compound is avery unstable(K=1.02) and for a while, it was to be a dissociation. Therefore, we believed that it was likely to a toxic substance.

• Journal of the Korean Society of Tobacco Science
• /
• v.2 no.1
• /
• pp.8-16
• /
• 1980

The cavity of triple filter was filled with the mixture of clinoptilolite and charcoal(1:1, V/V). The particle size of clinoptilolite was 30$\pm$5 A.S.T.M mesh. The reduction effects of the important gaseous components by this mixture were obtained as follows: 1) In comparison with the normal cellulose acetate niter, the contents of nicotine and T.P.M. were reduced about 35% and 22% respectively. 2) Many aliphatic and cyclic compounds were also substantially reduced in an average of 60%. 3) In contrast with the charcoal, the removal efficiency of clinoptilolite was revealed as higher (15-20%) in case of aliphatic compounds than the one (10-15%) of cyclic compounds. The above results showed us that the removal function of gaseous components was quite complementary each other (charcoal and clinoptilolite).

• Journal of environmental and Sanitary engineering
• /
• v.13 no.1
• /
• pp.69-81
• /
• 1998

The reactivity increase of unsunstituted energetic compound in cyclic ethers was found in order of three-membered cyclic form < five-membered cyclic form< four-membered cyclic form. The nucleophilicity and basicity of cyclic ethers can be explained by the negative charge on oxygen atom of cyclic ethers. The reactivity of propagation in the polymerization of cyclic ethers can be represented by positive charge on carbon atom and the LUMO energy of active species of cyclic ethers. The cationic polymerization of substituted cyclic ethers which have pendant energetic groups such as methoxy($-CH_{2}OCH_{3}$), azido($-CH_{2}N_{3}$), and nitrato($-CH_{2}ONO_{2}$) are investigated theoretically using the MNDO methods.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.1
• /
• pp.13-18
• /
• 2014

Bacillus subtilis JW-1 was isolated from rhizosphere soil as a potential biocontrol agent of bacterial wilt caused by Ralstonia solanacearum. Seed treatment followed by a soil drench application with this strain resulted in >80% reduction in bacterial wilt disease compared with that in the untreated control under greenhouse conditions. The antibacterial compound produced by strain JW-1 was purified by bioactivity-guided fractionation. Based on mass spectroscopy and nuclear magnetic resonance spectral data ($^1H$, $^{13}C$, $^1H-^1H$ correlation spectroscopies, rotating frame nuclear Overhauser effect spectroscopy, and heteronuclear multiple-bond correlation spectroscopy), the structure of this compound was elucidated as a cyclic lipopeptide composed of a heptapeptide (Gln-Leu-Leu-Val-Asp-Leu-Leu) bonded to a ${\beta}$-hydroxy-iso-hexadecanoic acid arranged in a lactone ring system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.17 no.6
• /
• pp.652-660
• /
• 2004

The cis-hex-3-ene-1,5-diynyl-bridged diiron compound 3, [(η$^{5}$ - $C_{5}$ M $e_{5}$ ) Fe(dppe)］$_2$($\mu$-C≡C-CH=CH-C≡C), have been prepared and characterized by cyclic voltammetry(CV), and electronic spectroscopy (UV-VIS and near-IR, NMR). From the results, compound 3 show two well resolved, single-electron, reversible oxidation waves by CV, and comproportionation constant(Kc) calculated from the CV data for compound 3. The Mixed-valence (MV) radical cation 3$^{+}$ show strong absorptions in the near IR, 1586 nm, and this band is more readily assigned as MV $\pi$-$\pi$ band of delocalized complex (Robin-Day Mixed-valence Class III), and the $H_{ab}$ , effective coupling parameter are most consistent with electronic delocalization.

• YAKHAK HOEJI
• /
• v.41 no.5
• /
• pp.547-553
• /
• 1997

The purpose of this investigation was to determine the inhibition on $Na^+,\;K^+$-ATPase, cyclic AMP phosphodiesterase and platelet activation by marine sterols isolated from octocorals. Three marine polyhydroxysterols, 7${\alpha},\;8{\alpha}-epoxy-3b{\beta},\;5{\alpha},\;6{\alpha}-trihydroxycholestane (1),\;24-methyl-7{\alpha},\;8{\alpha}-epoxy-3{\beta},\;5{\alpha},\;6{\alpha}-trihydroxycholest-22-ene (2),\;and\;7{\alpha},\;8{\alpha}-epoxy-3{\beta},\;5{\alpha},\;6{\alpha}-trihydroxycholest-22-ene (3)$, were isolated from the Gorgonian Acabaria undulata. Five marine sterols(compound 4, 5, 6, 7, 8) were isolated from the soft coral Alcyonium gracillimum. Three marine polyhydroxysterols (1, 2, 3) and pregna-1. 20-diene-3-one (8) exhibit a potent inhibitory effect on rabbit platelet aggregation induced by collagen and thrombin. Those polyhydroxysterols also exhibit a potent inhibitory effect on cyclic AMP phosphodiesterase. Compound 6 with an unusual cyclic enolether exhibit a inhibitory effect on $Na^+,\;K^+$-ATPase.

• Proceedings of the Korean Society for Language and Information Conference
• /
• 1998.02a
• /
• pp.303-309
• /
• 1998

• Natural Product Sciences
• /
• v.9 no.1
• /
• pp.44-48
• /
• 2003

The effect of aqueous extract of Stachys riederi var. japonica Miq. (Labiatae) (SRAE) on the immediate-type allergic reactions was investigated. SRAE was found to exhibit a inhibitory activity on the compound 48/80-induced systemic anaphylaxis in mice. SRAE inhibited the plasma histamine release induced by compound 48/80 in mice. In addition, SRAE also inhibited the passive cutaneous anaphylaxis reaction induced by IgE/anti-IgE in mice. The effect of SRAE on the histamine release from rat peritoneal mast cells (RPMC) was studied. SRAE inhibited the histamine release induced by compound 48/80 in RPMC. To clarify the mechanism of these inhibiting reactions, we investigated the effects of SRAE on cyclic AMP (cAMP). The level of cAMP in human leukemia cell line, HMC-1, when SRAE (1 mg/ml) was added, significantly increased compared with that of basal cells. These results indicate that SRAE may be beneficial in the treatment of immediate-type allergic reaction.