• Bulletin of the Korean Chemical Society
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• v.7 no.2
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• pp.120-124
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• 1986

In order to investigate effective solar energy conversion system, the light-induced electron transfer reactions have been examined across single-lamellar liposomes incorporated organic photosensitizers such as anthracene and naphthalene derivatives. We have observed photosensitized reduction of methyl viologen (1,1'-dimethyl-4,4'-$bipyridinium^{2+}$) dissolved in the exterior aqueous phase of the pigmented phospholipid liposomes when EDTA, as electron donor, is dissolved in the enclosed aqueous phase of the liposomes. The anthroyl stearic acid incorporated in the hydrophobic bilayer of liposomes leads to much less quantum yield for the photosensitized reduction of $MV^{2+}$ than the anthracene carboxylate incorporated in the outer hydrophilic layer. However, ${\beta}$-carotene with anthroyl stearic acid incorporated into the bilayer enhances the quantum yield significantly (${\Phi}{\simeq}0.2-0.3$), preventing the reverse reaction of electron transfer ($MV^+_\ {\rightarrow}MV^{2+}$) so that it might be useful for solar energy conversion into chemical energy. A naphthalene derivative, octadecyl naphthylamine sulfonic acid incorporated into the outer layer of liposomes results in less efficiency of $MV^{2+}$ reduction than anthroyl stearic acid. These results have been also tested with respect to lipid components of liposomes.

• Environmental Analysis Health and Toxicology
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• v.30 no.sup
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• pp.8.1-8.5
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• 2015

Objectives The objective of this study was to evaluate the biodegradation potential of four perfluorooctane sulfonic acid (PFOS) alternatives that were developed at Changwon National University. While PFOS has been used widely in industrial and consumer products, it is known to be a persistent organic pollutant. Therefore, greener alternatives are highly desirable. Methods Biodegradation tests were run for 28 days using standard test protocols. The biochemical oxygen demand was measured daily throughout the experimental period, and the data were used to calculate the biodegradation rates. Microorganisms were isolated from the some of the tests that showed evidence of biodegradation. Results $C_8H_8F_9KO_3S$, which has the same number of carbons as the parent compound PFOS but a reduced number of fluorines, showed the highest biodegradation rate followed by $C_{10}H_8F_{13}KO_3S$. Chemical alternatives with lower number of carbons did not biodegrade readily in the experiments. Conclusions Together, these results suggest that it may be advantageous to develop PFOS alternatives with 8 carbons, the same as PFOS, but a reduced number of fluorines; as such, chemicals are more susceptible to biodegradation than the parent compound.

• Membrane Journal
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• v.19 no.2
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• pp.96-103
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• 2009

A series of organic-inorganic composite membranes from poly(vinyl chloride) (PVC) graft copolymer electrolyte and heteropolyacid (HPA) were prepared for proton conducting membranes. First, poly(vinyl chloride)-g-poly(styrene sulfonic acid) (PVC-g-PSSA) was synthesized by atom transfer radical polymerization (ATRP) using direct initiation of the secondary chlorines of PVC. HPA nanoparticles were then incorporated into the PVC-g-PSSA graft copolymer though the hydrogen bonding interactions, as confirmed by FT-IR spectroscopy. The proton conductivity of the composite membranes increased from 0.049 to 0.068 S/cm at room temperature with HPA contents up to 0.3 weight traction of HPA, presumably due to both the intrinsic conductivity of HPA particles and the enhanced acidity of the sulfonic acid of the graft copolymer. The water uptake decreased from 130 to 84% with the increase of HPA contents up to 0.45 of HPA weight traction, resulting from the decrease in number of water absorption sites due to hydrogen bonding interaction between the HPA particles and the polymer matrix. Thermal gravimetric analysis (TGA) demonstrated the enhancement of thermal stabilities of the composite membranes with increasing concentration of HPA.

• Bulletin of the Korean Chemical Society
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• v.18 no.3
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• pp.274-280
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• 1997

The rates and stoichiometry of the reaction of gallane-trimethylamine with selected organic compounds containing representative functional groups were examined in tetrahydrofuran solution under standardized conditions (THF, 0 ℃). And its reducing characteristics were compared with those of aluminum hydride-triethylamine(AHTEA). The rate of hydrogen evolution from active hydrogen compounds varied considerably with the nature of the functional group and the structure of the hydrocarbon moiety. Alcohols, phenol, amines, thiols evolved hydrogen rapidly and quantitatively. Aldehydes and ketones were reduced moderately to the corresponding alcohols. Cinnamaldehyde was reduced to cinnamyl alcohol, which means that the conjugated double bond was not attacked by gallane-trimethylamine. Carboxylic acids, esters, and lactones were stable to the reagent under standard conditions. Acid chlorides also were rapidly reduced to the corresponding alcohols. Epoxides and halides were inert to the reagent. Caproamide and nitrile were stable to the reagent, whereas benzamide was rapidly reduced to benzylamine. Nitropropane, nitrobenzene and azoxybenzene were stable to the reagent, whereas azobenzene was reduced to 1,2-diphenylhydrazine. Oximes and pyridine N-oxide were reduced rapidly. Di-n-butyl disulfide and dimethyl sulfoxide were reduced only slowly, but diphenyl disulfide was reduced rapidly. Finally, sulfones and sulfonic acids were inert to the reagent under the reaction.

• Food Science and Preservation
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• v.25 no.1
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• pp.71-78
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• 2018

This study was carried out to investigate the quality characteristics and antioxidant activity of yogurt dressing prepared with different amounts (0, 5, 10, 15, and 20%) of black currant (Ribes nigrum L) extract. All samples were evaluated for chemical composition, pH, viscosity, sugar content, color, organic acid content and antioxidant activity. Our findings revealed that with increasing amounts of black currant extract in yogurt dressing, the moisture, crude protein and crude lipid contents decreased. The pH and viscosity gradually decreased, whereas the sugar increased with increase in black currant extract. Further, the lightness (L) value decreased, while the redness (a) and yellowness (b) values increased with increase in added black currant extract. Among the organic acids, the contents of citric acid, malic acid, succinic acid and acetic acid increased, while that of tartaric acid and lactic acid decreased with increasing levels of added black currant extract. The total polyphenol and total anthocyanin contents were 5.90-245.97 mg/100 g and 0.62-190.09 mg/100 g, respectively. In addition, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-thylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities significantly increased with increase in added black currant extract.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2724-2730
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• 2012

A new heterogeneous acidic catalyst was successfully prepared by impregnation of silica (Aerosil 300) by an acidic ionic liquid, named 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate [$PYC_4SO_3H$][$HSO_4$], and characterized using FT-IR spectroscopy, the $N_2$ adsorption/desorption analysis (BET), thermal analysis (TG/DTG), and X-ray diffraction (XRD) techniques. The amount of loaded acidic ionic liquid on Aerosil 300 support was determined by acid-base titration. This new solid acidic supported heterogeneous catalyst exhibits excellent activity in the synthesis of 2-aryl-2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation reaction of 2-aminobenzamide with aromatic aldehydes under solvent-free conditions and the desired products were obtained in very short reaction times with high yields. This catalyst has the advantages of an easy catalyst separation from the reaction medium and lower problems of corrosion. Recycling of the catalyst and avoidance of using harmful organic solvent are other advantages of this simple procedure.

• Journal of Information Display
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• v.6 no.4
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• pp.1-5
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• 2005

Perylene-based pyrrolopyrone derivative (PPD) was synthesized via condensation reaction with perylenetetracarboxylic dianhydride and 1,2-phenylenediarnine as n-type channel material. The structure of PPD was characterized by spectroscopic methods such FT-IR and $^1H$-NMR. PPD exhibited high thermal stability ($T_{d5wt%}: 560^{\circ}C$) and was found to be soluble only in protonic solvents with high acidity such as methane sulfonic acid and trifluoroacetic acid. The PPD solution showed maximum absorption and emission at 601 and 628 nm, respectively. Thin film transistors were fabricated by vacuum deposition and solution casting method. The electron mobilities of the devices were achieved as high as $0.17{\times}10^{-6}cm^2/Vs$ for vacuum deposited device and $0.4{\times}10^{-6}cm^2/Vs$ for spin coated device, respectively.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.318-318
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• 2009

관행재배 농산물에 대한 유기재배 농산물의 생리활성성분 및 기능성 측면에서의 우수성에 대한 관심이 국제적으로 화두가 되고 있으나 일관성 있는 데이터가 제시되지 못해 논란이 이어지고 있다. 그래서 본 연구에서는 한국인이 일상적으로 섭취하고 있는 고추(녹광)를 대상으로 생산이력이 분명한 관행 및 유기 재배 시료를 이용해 주의 깊게 확립된 분석법을 이용해 유기 및 관행재배 고추의 생리활성성분 함량비교 및 기능성 평가를 행하였다. 그 결과 ascorbic acid, capsaicin, dihydrocapsaicin 및 총 페놀성 화합물의 함량은 녹색 및 적색 고추 모두에 있어 관행보다 유기재배 고추가 유의(p<0.05)하게 더 높은 값을 보였다. 그리고 flavonoid류(apigenin, luteolin, quercetin)의 함량은 녹색과 적색고추 모두 유의차는 인정되지 않았으나 관행보다 유기재배 고추에서 더 높은 경향을 나타냈다. 또 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid ammonium salt) (ABTS+) radical-scavenging 활성은 녹색고추에 있어서는 유기재배 고추가 관행재배 고추보다 더 높은 경향을 보였으며, 적색고추에 있어서는 유의(p<0.05)하게 높은 활성을 보였다. 고추추출물을 경구투여한 쥐 (Sprague-Dawley, 6주령, men, 180~250 g) 혈장의 동이온 유도산화에 대한 cholesteryl ester hydroperoxide (CE-OOH) 생성 억제능을 평가한 결과, 고추추출물을 경구투여한 쥐가 대조구보다 더 높은 CE-OOH 생성 억제능과 lag time연장 효과가 있음을 알 수 있었으며, 그 효과는 관행재배 고추보다 유기재배 고추에 있어서 더 우수한 것으로 관찰되었고, 녹색고추보다 적색고추에 있어 그 효과가 더 뛰어난 것으로 평가되었다. 이러한 결과는 위에서 분석한 각 시료에 함유된 항산화 성분들의 함량과 관련이 있는 결과라 판단되며, 유기재배 고추가 관행재배 고추보다 유용성분 및 생리활성 측면에서 더 우수함을 시사하는 결과라 사료된다. 그러나 한편으로 본 연구결과는 고추에 국한된 성과라 할 수 있으며, 유기재배 방법 및 다양한 환경조건에 따라 그 결과 또한 다양성을 보일 수 있음에 주의를 기울일 필요가 있다고 판단된다.

• Bulletin of the Korean Chemical Society
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• v.15 no.10
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• pp.873-881
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• 1994

The approximate rate and stoichiometry of the reaction of excess diisobutylaluminum hydride-dimethyl sulfide complex($DIBAH-SMe_2$) with organic compounds containing representative functional group under standardized conditions (toluene, $0{\circ}C$) were examined in order to define the reducing characterstics of the reagent and to compare the reducing power with DIBAH itself. In general, the reducing action of the complex is similar to that of DIBAH. However, the reducing power of the complex is weaker than that of DIBAH. All of the active hydrogen compounds including alcohols, amines, and thiols evolve hydrogen slowly. Aldehydes and ketones are reduced readily and quantitatively to give the corresponding alcohols. However, $DIBAH-SMe_2$ reduces carboxylic acids at a faster rate than DIBAH alone to the corresponding alcohols with a partial evolution of hydrogen. Similarly, acid chlorides, esters, and epoxides are readily reduced to the corresponding alcohols, but the reduction rate is much slower than that of DIBAH alone. Both primary aliphatic and aromatic amides examined evolve 1 equiv of hydrogen rapidly and are reduced slowly to the amines. Tertiary amides readily utilize 2 equiv of hydride for reduction. Nitriles consume 1 equiv of hydride rapidly but further hydride uptake is quite slow. Nitro compounds, azobenzene, and azoxybenzene are reduced moderately. Cyclohexanone oxime liberates ca. 0.8 equiv of hydrogen rapidly and is reduced to the N-hydroxylamine stage. Phenyl isocyanate is rapidly reduced to the imine stage, but further hydride uptake is quite sluggish. Pyridine reacts at a moderate rate with an uptake of one hydride in 48 h, while pyridine N-oxide reacts rapidly with consumption of 2 equiv of hydride for reduction in 6h. Similarly, disulfides and sulfoxide are readily reduced, whereas sulfide, sulfone, and sulfonic acid are inert to this reagent under these reaction conditions.

• Bulletin of the Korean Chemical Society
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• v.13 no.5
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• pp.531-537
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• 1992

The approximate rates and stoichiometry of the reaction of excess potassium 2-thexyl-1,3,2-dioxaborinane hydride(KTDBNH) with 55 selected compounds containing representative functional groups under standardized conditions (tetrahydrofuran, TEX>$0^{\circ}C$, reagent : compound=4 : 1) was examined in order to define the characteristics of the reagent for selective reductions. Benzyl alcohol and phenol evolve hydrogen immediately. However, primary, secondary and tertiary alcohols evolve hydrogen slowly, and the rate of hydrogen evolution is in order of $1^{\circ}$> $2^{\circ}$> $3^{\circ}$. n-Hexylamine is inert toward the reagent, whereas the thiols examined evolve hydrogen rapidly. Aldehydes and ketones are reduced rapidly and quantitatively to give the corresponding alcohols. Cinnamaldehyde is rapidly reduced to cinnamyl alcohol, and further reduction is slow under these conditions. The reaction with p-benzoquinone dose not show a clean reduction, but anthraquinone is cleanly reduced to 9,10-dihydro-9,10-anthracenediol. Carboxylic acids liberate hydrogen immediately, further reduction is very slow. Cyclic anhydrides slowly consume 2 equiv of hydride, corresponding to reduction to the caboxylic acid and alcohol stages. Acid chlorides, esters, and lactones are rapidly and quantitatively reduced to the corresponding carbinols. Epoxides consume 1 equiv hydride slowly. Primary amides evolve 1 equiv of hydrogen readily, but further reduction is slow. Tertiary amides are also reduced slowly. Both aliphatic and aromatic nitriles consume 1 equiv of hydride rapidly, but further hydride uptake is slow. Analysis of the reaction mixture with 2,4-dinitrophenylhydrazine yields 64% of caproaldehyde and 87% of benzaldehyde, respectively. 1-Nitropropane utilizes 2 equiv of hydride, one for hydrogen evolution and the other for reduction. Other nitrogen compounds examined are also reduced slowly. Cyclohexanone oxime undergoes slow reduction to N-cyclohexylhydroxyamine. Pyridine ring is slowly attacked. Disulfides examined are reduced readily to the correponding thiols with rapid evolution of 1 equiv hydrogen. Dimethyl sulfoxide is reduced slowly to dimethyl sulfide, whereas the reduction of diphenyl sulfone is very slow. Sulfonic acids only liberate hydrogen quantitatively without any reduction. Finally, cyclohexyl tosylate is inert to this reagent. Consequently, potassium 2-thexyl-1,3,2-dioxaborinane hydride, a monoalkyldialkoxyborohydride, shows a unique reducing characteristics. The reducing power of this reagent exists somewhere between trialkylborohydrides and trialkoxyborohydride. Therefore, the reagent should find a useful application in organic synthesis, especially in the field of selective reduction.