• Applied Biological Chemistry
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• 제45권4호
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• pp.207-211
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• 2002

포도의 가식성 코팅물질로 methyl cellulose에 별도로 미생물 생육억제 효과가 있는 n-capric acid isopropyl ester와 sodium nitrate를 spray한 다음 EPS(expanded polystylene) tray에 0.05mm PE(polyetlylene) 필름으로 wrapping한 후 $30^{\circ}C$에서 16일간 저장하면서 품질을 분석하였다. 중량감소율에서 상품가치를 잃게 되는 7%수준이 되는 시점이 대조구는 6일인 반면 methyl cellulose+n-capric acid isopropyl ester처리구는 9일로 차이를 보였다. 대조구의 산도는 처리구에 비하여 저장기간이 길어짐에 따라서 감소율이 높게 나타났다. Vitamin C 함량의 경우 대조구는 저장초기에 비하여 저장 16일 후 68.4% 감소한 반면 methyl cellulose + sodium nitrate와 methyl cellulose + n-capric acid isopropyl ester 처리구는 각각 51.5와 49.8%의 감소를 나타내었다. 경도변화로는 대조구가 가장 크게 감소하여 저장 16일째 초기에 비하여 44.2% 감소한 반면 methyl cellulose + sodium nitrate와 methyl cellulose + n-capric acid isopropyl ester 처리구는 각각 26.5와 23.2%로 나타나 큰 차이를 보였다. 저장기간 중 sodium nitrate와 n-capric acid isopropyl ester 처리가 총균수와 효모수의 억제에 효과가 있었으며 관능검사의 기호도에서는 methyl cellulose 처리구보다 methyl cellulose + sodium nitrate 처리구와 methyl cellulose + n-capric acid isopropyl ester 처리구가 높게 나타났다.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.546-550
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• 2014

Relative reactivity of various carbonyl and acid derivatives in MPV-type (Meerwein-Ponndorf-Verley) reduction with an DIBAL(F) model has been studied via DFT and MP2 methods. Free energies of initial adduct formation (-Gadd) of DIBAL(F) model and carbonyls are in the order of amide < ester < aldehyde < ketone < acid chloride; in the alan-amide adduct, the developed positive charge at carbonyl carbon is expected to be stabilized by amide resonance, but in the acid chloride adduct it is destabilized by inductive effect of chloride. However the TS barrier energies (${\Delta}G_{TS}$) for the MPV-type hydride reduction of the carbonyl adducts are in the order of aldehyde < ketone < acid chloride << ester < amide; presumably decreasing order of electrophilicity of carbonyl carbon at adducts, which is well correlated with experimental data. It is noted that the relative reactivity of carbonyl derivatives in MPV-type reduction with DIBAL(X) is not governed by the alan-adduct formation energies, but follows the order of electrophilicity of carbonyl carbon of transition states.

• Applied Biological Chemistry
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• 제13권3호
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• pp.197-205
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• 1970

1. myo-inositol (aeeeee) 에서 scyllo- (eeeeee), epi-(aeaeee) 및 muco-inositol (aaaeee)에 도달(到達)시킬 수 있었다. 2. inositol의 과산화수소(過酸化水素) 산화(酸化)는 ax. 수산기(水酸基)가 산화(酸化)되어 microbial oxidation, 접촉산화(接觸酸化)에서와 대등(對等)한 inosose를 얻고, 이것은 산성(酸性)에서 $NaBH_4$로 환원(還元)하면 eq.-alcohol이 되며, 한편 접촉산원(接觸還元)하면 az. alcohol 이 된다. 3. inositol의 p-HBA ester인 사종(四種) 신화합물(新化合物) [III], [XII], [XVI], [XXI]을 합성(合成)하였다. 4. 이들 ester는 모두 항균작용(抗菌作用)이 있고 pH의 저하(低下)로 증대(增大)되는 경향(領向)이 있으며 muco-inositol ester는 가장 강력(强力)하고, 이는 입체구조(立體構造)와 관련(關聯)되는 것 같다.

• Bulletin of the Korean Chemical Society
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• 제7권4호
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• pp.296-298
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• 1986

Carboxylic acid anhydrides are rapidly reduced with borane-lithium chloride (1:0.1) system to give corresponding alcohols (diols in the case of cyclic anhydride) quantitatively in tetrahydrofuran at room temperature. This reagent tolerates aromatic acid ester, nitro, and halide functional groups, however competitively reduces aliphatic ester and nitrile groups.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.267-276
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• 2005

This study was carried out to investigate the effect of phytosterol ester addition on lowering blood cholesterol in cholesterol-reduced Cheddar cheese. For cholesterol removal, separated cream was treated with 10% ${\beta}$-cyclodextrin at 800 rpm, then blended with remaining skim milk and homogenized with 1,000 psi at $70^{\circ}C$. Experimental cheeses were manufactured by five different levels of phytosterol addition. After the cholesterol reduction process by ;${\beta}$-cyclodextrin, the cholesterol removal rate was in the range of 91.0 to 92.1%. Amount of short-chain free fatty acid and free amino acids increased with an increase of phytosterol ester, and those were significantly different from that of control in all ripening periods. All rheological properties also increased with an increase of phytosterol ester during ripening period. In sensory analysis, the scores of rancid, bitterness Cheddar flavor and off-flavor intensities increased significantly, while texture was decreased during ripening in phytosterol ester-added groups. Total blood cholesterol was reduced by 18% when rats were fed Cheddar cheese treated with 8% phytosterol. The present study indicated that phytosterol ester addition resulted in a profound lowering effect of blood with cholesterol-reduced Cheddar cheese.

• 대한화학회지
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• 제61권5호
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• pp.244-250
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• 2017

Reduction of (${\pm}$)-3-ketoproline ethyl ester (1) by $NaBH_4$ in the presence of $CaCl_2$ and $MgCl_2$ as the chelating agents gave selective products cis-3(R/S)-alcohols, while reduction by $NaBH_4$ alone or chelated with $NiCl_2$ and $AlBr_3$ gave mixtures of cis- and trans-alcohols. The reduction of (${\pm}$)-1 by various vegetables however, gave exclusively the cis-alcohol as the major and trans-alcohol as the minor. On the contrary, reduction of (${\pm}$)-1 by carrot afforded a mixture of cis- and trans-alcohols, in which the trans-alcohol exists as the major product. In addition, we found that this biocatalyst selectively converted S-enantiomer of (${\pm}$)-1 to the cis-alcohol, and R-enantiomer to a mixture of cis- and trans-alcohols with cis-alcohol as the major product. This fact prompted us to use various fresh plant tissues for stereoselective reduction of diverse types of pyrrolidinones, as its stereoselectivity towards racemic mixtures is higher compared to that using chemical reducing agents.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2517-2518
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• 2007

• 약학회지
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• 제33권5호
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• pp.290-295
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• 1989

2,6-Dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3-carboxylic acid methyl ester (1) was formylated to 2,6-dimethy-4-(3'-nitrophenyl)-5-formyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (2) in 76% yield. At the elevated temperature, 2,6-dimethyl-4-(3'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-monomethyl ester (3) was also converted into compound 2 in 46% yield. The compound 2 was reduced to 2,6-dimethyl-4-(3'-nitrophenyl)-5-hydroxymethyl-1,4-dihydropyridine-3-carboxylic acid methyl ester (4) in 91% yield. Compound 2 was reacted with triethyl phosphonoacetate to give 2,6-dimethyl-4-(3'-nitrophenyl)-5-(2-ethoxycarbonyl ethenyl)-1,4-dihydropyridine-3-carboxylic acid methyl ester (5) in 50% yield. Reaction between compound 2 and amines (methyl amine, ethylamine, methoxylamine, hydroxyl amine, phenyl hydrazine and 1-amino-4-methyl piperazine) gave six schiff bases 7a, 7b, 7c, 7e, 7f in 81%, 91%, 82%, 81%, 50% and 84% yield, respectively.

• 한국축산식품학회:학술대회논문집
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• 한국축산식품학회 2004년도 정기총회 및 제33차 춘계 학술대회
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• pp.334-336
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• 2004

This study was carried out to investigate the effect of phytosterol ester addition on lowering blood cholesterol in cholesterol-reduced Cheddar cheese, which was manufactured by the mixture of cholesterol-reduced cream and skim milk. After the cholesterol reduction process by ${\beta}$-CD treatment, the cholesterol removal rate was in the range of 91.2 to 92.1%. In animal study, 18% of total blood cholesterol was lowered in 8% phytosterol ester-added Cheddar cheese, which was significantly different from that of control. The present study indicated that phytosterol ester addition showed a profound lowering effect of blood with cholesterol-reduced Cheddar cheese.

• 에너지공학
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• 제18권3호
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• pp.203-211
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• 2009

기존의 CFC 계열 및 HCFC 계열 냉매들이 오존층 붕괴와 지구온난화의 원인들 중의 한가지로 밝혀지면서 이것을 대체할 수 있는 냉매의 개발은 주요한 연구과제였다. 이제 몇 가지 대체 냉매들이 개발되면서 이것들 이 냉동시스템에 사용될 때 발생하는 상용성 (Compatibility)이 연구될 필요가 있다. 본 연구에서는 대체냉매의 상용성 연구의 일환으로 1,1,1,2-Tetrafluoroethane(HFC-134a) +1,1,1-Trifluoroetane(HFC-143a) + Pentafluoroethane (HFC-125)의 혼합대체냉매 HFC-404a 와 냉매 윤활유의 하나인 POE 오일 혼합물의 증기압을 측정하였다. 측정온도범위는 냉매 시스템의 운전온도를 고려하여, 263.15K 에서 323.15 K로 하였으며 오일농도범위는 0 mass% 에서 90 mass% 까지로 하였다. 측정결과 273.15K 이하의 온도에서 오일 농도 30 mass%까지 증기압에 대한 오일의 영향은 미미하였으며 50 mass% 이상에서는 증기압이 급격히 떨어지는 것이 밝혀졌다. 측정자료를 이용하여 HFC-404a와 POE 오일 혼합물의 증기압을 예측할 수 있는 모형을 개발 하기 위하여 Rault 모델과 Flory-Huggins 모델을 사용하여 측정치와 비교하였다. 그리고 보다 정확하고 실용적으로 증기압을 예측할 수 있는 경험식을 도출하였다.