• Bulletin of the Korean Chemical Society
• /
• v.25 no.12
• /
• pp.1755-1756
• /
• 2004

• Journal of Nutrition and Health
• /
• v.13 no.3
• /
• pp.150-154
• /
• 1980

For the purpose of clarifying the changes of free amino acid content in seeds of Korean mung bean during the ripening process, samples ranging in five stages-10, 15, 20, 25 and 30 days after blooming were collected. The results obtained were as follows: 1) Amino acids detected in the first stage were lysine, histidine, arginine, cystine, aspartic acid, threonine (including serine), glutamic acid, valine, methionine sulfoxide and methionine sulfone. 2) In the second stage (15 days after blooming) more amino acids such as glycine, isoleucine, tyrosine, phenylalaninc, and methionine were detected in addition to those in the first stage. More methionine was appeared, while the level of methionine sulfoxide and methionine sulfone was decreased. 3) In the 3rd stage leucine was first detected. The level of leucine was increased slowly as the seed was being ripened. After 4th stage methionine sulfoxide and methionine sulfone were not detected, while the level of methioniene was steadily increased. 4) After 20 days the levels of lecuine, valine. isoleucine, and methionine were increased, while the others were either decreased or remained at the same level.

• Membrane Journal
• /
• v.22 no.3
• /
• pp.191-200
• /
• 2012

New composite membranes were manufactured by impregnating post-sulfonated poly(arylene ether sulfone)s containing perfluorocyclobutane (PFCB) groups into porous polytetrafluoroethylene (PTFE) films. Two kinds of post-sulfonated poly(arylene ether sulfone)s with two different monomer ratios (sulfonable biphenylene monomer : non-sulfonable sulfonyl monomer = 6 : 4, 4 : 6) were first prepared through three synthetic steps: synthesis of trifluorovinylether-terminated monomers, thermal cycloaddition polymerization and post-sulfonation using chlorosulfonic acid (CSA). The composite membranes were then prepared by adjusting the concentrations (5~20 wt%) of the resulting copolymers impregnated in the PTFE films. The water uptake, ion exchange capacity (IEC) and ion conductivity of the composite membranes were characterized and compared with their unreinforced dense membranes and Nafion. All the synthesized compounds, monomers and polymers were characterized by $^1H$-NMR, $^{19}F$-NMR and FT-IR and the composite membranes were observed with scanning electron micrographs (SEM).

• Journal of the Korean Chemical Society
• /
• v.36 no.6
• /
• pp.925-932
• /
• 1992

Total synthesis of 9,10-dideoxyrhodomycinone(30) which is the late-stage precursor of naturally occuring ${\beta}$-rhodomycinone(1) is described. After phthalide sulfone 4 was converted to naphthalide sulfone 12 by the several step. Michale addition of naphthalide sulfone 12 which was converted to an anion with 5-ethyl-1,3-cyclohexenone(21) gave a good yield of linearly condensed tetracyclic ketone compound 26. The keto group of 26 was reduced with sodium borohydride and protected by methyl group to afford compound 28. 9,10-Dideoxy-${\beta}$-rhodomycinone(30) was synthesized from pentamethoxy tetracyclic compound 28 by oxidative demethylation and demethylation of 29.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.05a
• /
• pp.122-122
• /
• 1998

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.52 no.5
• /
• pp.461-467
• /
• 2019

Several studies investigating the prevention and treatment of external parasites in farmed olive flounder Paralichthys olivaceus have found that the anticoccidial agent toltrazuril sulfone is an effective antiparasitic. Prior to undertaking a full-scale study, we developed analytical methods to detect the levels of toltrazuril and toltrazuril sulfone in farmed flounder samples using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS/MS). This analysis showed that LC-MS/MS changed the mobile phase and collision energy of toltrazuril and toltrazuril sulfone. This was validated using established conditions. Sample pre-treatment for this process involved extraction with dichloromethane and purification by liquid-liquid extraction in formic acid, acetonitrile, and h-hexane, followed by determination of all compounds by LC-MS/MS. Separation was achieved within 10 min by gradient elution using a Capcell Pak C18 ($3.0{\mu}m$, $100{\times}2.0mm$) analytical column (Shiseido UG 120V) with a mixture of 0.1% (v/v) formic acid and acetonitrile. Multiple reaction monitoring was used for selective detection of toltrazuril and toltrazuril sulfone. This method yields satisfactory results for linearity, precision, and limits of quantification. Therefore, the method established in our study will serve as a basis for further research on parasite control by toltrazuril and toltrazuril sulfone.

• Applied Chemistry for Engineering
• /
• v.4 no.3
• /
• pp.544-548
• /
• 1993

Glass transition temperatures($T_g$) of poly(phenylene sulfide sulfone)[PPSS], which were heat treated at various temperature and time, were studied by DSC. Up to $230^{\circ}C$, $T_g$ of heat treated PPSS were increased with increasing the heat treated time. When the sample was heated at $260^{\circ}C$ for 30 minute and $280^{\circ}C$ for 10 minute, however, $T_g$ of those samples were decreased. These phenomena can be explained by the factors of chain extension reaction, oxidative crosslinking, and thermal crosslinking.

• Korean Journal of Veterinary Research
• /
• v.55 no.3
• /
• pp.199-204
• /
• 2015

4,4'-diaminodiphenyl sulfone (dapsone) is a sulfone drug that has antibacterial effects on a variety of bacteria, especially Mycobacterium leprae; thus, it has been used to treat leprosy. Previous studies demonstrated that dapsone inhibits integrin-mediated adherence of neutrophils and production of prostaglandin $E_2$ by polymorphonuclear leukocytes. Hence, dapsone may act in immune cells and regulate cell-mediated inflammation processes. However, its anti-inflammatory effects remain unclear. The present study demonstrated that dapsone modulates the production of inflammation-related cytokines in immune cells. We employed the spleen cells of mice, which are major immune cells, and lipopolysaccharide (LPS) as a causative agent of inflammation for experiments. Dapsone induced a proportional change in splenocyte subsets and the apoptosis of spleen cells. Interestingly, dapsone decreased the production of tumor necrosis factor-alpha and interleukin (IL)-10, but not IL-6, in LPS-treated spleen cells. In other assays, we measured the dapsone-induced production of nitric oxide (NO) and the expression of activation markers of spleen cells. Dapsone decreased NO production in LPS-treated spleen cells. Taken together, our results demonstrate that dapsone has anti-inflammatory effects in immune cells and provide new insight into the potential uses of this agent.

• Applied Chemistry for Engineering
• /
• v.16 no.1
• /
• pp.144-149
• /
• 2005

Sulfonated poly(ether ether ketone) (SPEEK) was blended with poly(ether sulfone) (PES) at various compositions. To investigate the possibility of using the blend membranes as polymer electrolyte membranes for direct methanol fuel cell, the blend membranes were characterized in terms of methanol permeability, proton conductivity, ion exchange capacity, and water content. Both proton conductivity and methanol permeability of SPEEK were relatively high. As the amount of PES increased, methanol permeability decreased more rapidly compared to proton conductivity. The experimental results indicated that the blend membrane with 40 wt% PES was the best choice in terms of the ratio of proton conductivity to methanol permeability.

• Journal of the Korean Chemical Society
• /
• v.37 no.1
• /
• pp.141-147
• /
• 1993

A brief route for total synthesis of 6-deoxybisanhydrodaunomycinone(20) was described, namely the precursor of the daunomycinone, the aglycone of the anticancer antibiotic daunorubicin (1b). The prepared enone 4 was condensed with phthalide sulfone 7 to afford anthraquinone 10 after oxidation and methylation. The benzylic group of 10 was brominated, and subsequent oxidation with bis(tetrabutylammonium) dichromate followed by cyclization give hydroxyanthraquinone 16, which was displaced with thiophenol. Oxidation of 17 with m-CPBA in phosphate buffer solution afforded anthraquinonyl sulfone 18 which was condensed with methyl vinyl ketone (19) to furnish 20.