• 대한화학회지
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• 제53권3호
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• pp.244-256
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• 2009

소랄렌과 피리디민 염기와의 $C_4$-고리화 부가반응을 통한 가닥내 교차 결합(interstrand crosslinking) 에 의해 만들어진 소랄렌 복합체를 ab initio 방법인 HF와 DFT 6-31G 방법을 이용하여 연구하였다. 소랄렌과 피리디민 염기에 의해 만들어진 광생성물인 8-MOP< >Thy, Ps< >Cyt, Ps< >Thy, Ps< >Ps, Thy< >(3, 4)Ps(12, 13)< >Thy의 최적화된(optimized) 구조를 알 수 있으며, 8-MOP< >Thy은 (trans-syn) 구조, Ps(3, 4)< >Cyt은 (trans-anti) 구조, Ps(12, 13)< >Cyt은 (trans-anti) 구조, Ps(3, 4)< >Thy은 (trans-syn) 구조, Ps(12, 13)< >Thy은 (trans-syn) 구조가 가장 유리하다. Ps(3, 4)< >Thy과 Ps(12, 13)< >Thy의 Gibbs 자유 에너지 변화(${\Delta}{G^{\circ}}$)를 비교하면 Ps(12, 13)< >Thy의 광생성물(단일부가 생성물)이 이루어진 뒤에 Ps(3, 4)< >Thy의 광고리화 부가반응 생성물(이중부가 생성물)을 형성한다는 사실을 알 수 있다. Bispsoralen(psoralen dimer)에서는 Ps(12, 13)< >Ps(12, 13)(trans-anti) 구조가 가장 유리하며, Thy< >(3, 4)Ps(12, 13)< >Thy에서는 (cis syn)(cis anti) 형태가 가장 유리하다.

• 열처리공학회지
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• 제13권3호
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• pp.151-157
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• 2000

This study aims to investigate the effect of carbon content on the surface nitrogen permeation of 13%Cr-1.8%Al alloyed stainless steels. The surface nitrogen permeation was performed at $1050^{\circ}C{\sim}1200^{\circ}C$ in the $1kg/cm^2$ nitrogen gas atmosphere. The nitrogen permeated surface layer of the specimen containing 0.03%C consists of AlN, martensite and retained austenite phases. while the surface layer of the specimen containing 0.14%C appears the $AlFe_3C_x$ phase including former three phases. The specimen containing 0.14%C shows lower total case depth than that containing 0.03%C at the nitrogen permeation temperatures of $1050^{\circ}C$ and $1100^{\circ}C$, while the total case depth of the specimen containing 0.14%C is remarkably increased at the temperature of $1150^{\circ}C$ and $1200^{\circ}C$ due to the increase in the retained austenite content. Martensitic phase, AlN and $AlFe_3C_x$ precipitate of the nitrogen permeated surface layer cause to increase the surface hardness of 550~600Hv.

• 한국자기공명학회논문지
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• 제15권2호
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• pp.115-127
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• 2011

A newly developed cost-effective approach to prepare $^{15}N/^{13}C$-labeled protein for NMR studies is presented. This method has been successfully applied to isotopically labeling of PTK6 SH2 domain and MTH 1880 protein. The production method generates cell density using a growing media containing $^{15}NH_4Cl$, $^{12}C_6$-D-glucose. Following a doubling time period for unlabeled metabolite exhaustion and then addition $^{13}C_6$-D-glucose into a M9 growing media, the cells are induced. Our results demonstrate that in order to get full incorporation of $^{13}C$, the isotopes are not totally required during the initial growth phase before induction. The addition of small amounts of $^{13}C_6$-D-glucose to the induction phase is sufficient to obtain more than 95% incorporation of isotopes into the protein. Our optimized protocol is two-thirds less costly than the classical method using $^{13}C$ isotope during the entire growth phase.

• Journal of the Korean Wood Science and Technology
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• 제17권4호
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• pp.44-56
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• 1989

Kraft pulp 폐액에 다량 존재하는 lignin을 회수 이용하기 위하여 폐액을 조제하고 유기용매로 추출 정제하여 각 fraction별로 $^{13}C$-NMR 및 IR 스펙트라로 측정분석하였다. 그 결과 Kirk 방법보다는 M$\ddot{o}$rck 방법으로 정제한 시료가 lignin의 특징적인 signal들을 많이 나타나고 있는 점과 특히 MCS fraction은 방향핵이나 측쇄의 signal들이 잘 나타나고 있으며, KLI fraction에서는 methoxyl기와 C-${\beta}$의 signal이 잘 나타나고 있는 것을 알 수 있었다.

• Mycobiology
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• 제41권3호
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• pp.139-144
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• 2013

Makgeolli is a traditional cloudy-white Korean rice wine with an alcohol content of 6~7%. The present study investigated the morphological characteristics, carbon-utilizing ability, fatty acid composition, alcohol resistance, glucose tolerance, and flocculence of Saccharomyces cerevisiae Y98-5 and Pichia anomala Y197-13, non-S. cerevisiae isolated from Nuruk, which is used in brewing Makgeolli. Similar morphological characteristics were observed for both isolated wild yeast strains; and the carbon source assimilation of Y197-13 differed from that of other P. anomala strains. Strain Y197-13 was negative for D-trehalose, mannitol, arbutin, I-erythritol, and succinic acid. The major cellular fatty acids of strain Y197-13 included C18:2n6c (33.94%), C18:1n9c (26.97%) and C16:0 (20.57%). Strain Y197-13 was Crabtree-negative, with 60% cell viability at 12% (v/v) ethanol. The flocculation level of strain Y197-13 was 8.38%, resulting in its classification as a non-flocculent yeast.

• 공업화학
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• 제7권6호
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• pp.1096-1104
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• 1996

새로운 항균제 및 항종양제를 합성하기 위하여 norfloxacin(8) 또는 ciprofloxacin(9)이 pteroic acid의 C-9위치에 치환되고 C-2 위치에 아미노기 대신 $CH_3$기가 치환된 새로운 pteroic acid 유도체 13a와 13b를 합성하였다. 이는 출발 물질인 norfloxacin과 ciprofloxacin의 piperazine N-4 위치에 2-amino-3-cyano-5-chloro-methylpyrazine(20)을 결합하여 1-alkyl(ethyl, cyclopropyl)-6-fluoro-1,4-dihydro-4-oxo-7-[[4-N- (2-amino-3-cyanopyrazin-5-yl)methyl]piperazin-1-yl]-3-quinolinecarboxytic acid(12a, 12b)를 합성하였다. 이를 각각 acetamidine. HCl과 고리화시켜 C-2 위치에 아미노기 대신 $CH_3$기가 치환된 새로운 pteroic acid 유도체 135와 13b를 각각 76.2%와 82.8%의 수율로 합성하였다. 그리고 이들 화합물에 대한 항균활성의 측정은 Pseudomonas aeruginosa ATCC9027을 포함하여 Gram-positive와 Gram-negative bacteria에 대하여 검토한 결과 합성한 화합물 13a와 13b는 일반적으로 norfloxacin보다 낮은 항균활성을 나타냈다.

• 한국광물학회지
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• 제24권4호
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• pp.289-300
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• 2011

규산염 물질의 탄소 용해도에 대한 미시적 연구는 규산염 물질의 성질 변화와 지구 시스템 진화에 탄소가 미치는 영향의 이해에 매우 중요하다. 본 연구에서는 탄소가 용해된 엔스테타이트 시료에 대하여 라만(Raman) 분광분석을 실시하고, 양자 화학 계산을 통해 결정구조 내에 용해된 탄소의 원자 환경과 핵자기공명 분광 특성을 예측하였다. 1.5 GPa $1,400^{\circ}C$의 온도 압력 조건에서 2.4 wt%의 비정질 탄소와 함께 합성한 엔스테타이트의 라만 실험에서 엔스테타이트의 진동양상은 확인할 수 있었으나, $CO_2$나 탄산염 이온의 진동양상에 대한 정보는 획득하지 못하였다. 이는 엔스테타이트 내에 용해된 탄소의 양이 매우 적어 시료를 구성하는 원자들의 집합적인 진동양상을 측정하는 라만 분광분석으로는 검출이 어려움을 지시한다. 특정 핵종 중심의 핵자기공명 분광분석을 이용하면, 구조 내에 존재하는 탄소만 선택적으로 측정할 수 있다. 특히 $^{13}C$ NMR 화학 이동(chemical shift)은 원자 환경에 따라 민감하게 변하므로, 양자 화학 계산을 이용하여 $CO_2$와 C가 치환된 엔스테타이트 클러스터의 $^{13}C$ NMR 화학 차폐 텐서(chemical shielding tensor)를 계산하였다. 계산 결과 $CO_2$의 피크는 125 ppm에서 나타나며 이는 기존의 실험결과와 일치하며, 상압에서는 생성이 어렵지만 고압환경에서 생성될 가능성이 있는 배위수가 4인 C의 화학 이동 값은 ~254 ppm으로 예측되었다. 이와 같은 양자 화학 계산 결과는 고분해능 $^{13}C$ NMR 실험의 이해를 돕고 탄소의 원자 환경을 연구하는데 도움을 줄 것이다.

• Bulletin of the Korean Chemical Society
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• 제13권6호
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• pp.595-599
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• 1992

The temperature dependence of C-13 chemical shifts are observed for the cyclooctanone arylhydrazones. The temperature-dependent chemical shifts for these derivatives are explained by postualating the existence of two equilibrating structures. In addition, the assignment between the $^{13}C$ signals of methylene carbon pairs can be done by application of the ${gamma}$ -substituent effect.

• 생약학회지
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• 제8권1호
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• pp.17-21
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• 1977

$^{13}C-NMR$ behaviors of phenolic compounds such as phenol, catechol, pyrogallol, resorcine, phoroglucine and hydroquinone were studied. From the study on the effects of OH-substitution on benzene and its dervatives it was found that the additivity rule can be applied to the ortho-and para-effect but not to the meta-effect for the OH-function. The empirically calculated chemical shifts regarding the o-and p-effects coincide very well with the results of measurement. The chemical shifts of the phenolic compounds can be classified into three types. 1) Catechol-type C-1 and C-2 145 ppm C-3 and C-6 116-107 ppm 2) Pyrogallol-type C-1 132ppm C-2 and C-6 146ppm C-3 and C-5 106ppm 3) Resorcin-type C-1 and C-3 159ppm C-2 103-95ppm C-4 and C-6 107ppm

• 한국잠사곤충학회지
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• 제17권2호
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• pp.161-170
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• 1975

This study is to investigate the content of crude protein intruded in the sericin of cocoon shell and pupa by treatment of buffer solution (pH 1 to pH 13) 20 ml per 1 gram for 30 and 60 minutes at 30$^{\circ}C$, 60$^{\circ}C$ and 100${\pm}$2$^{\circ}C$, respectively. The results obtained are summarized as follows. 1. The quantity of total crude protein obtained from cocoon shell and pupa by treatment during 30 minutes at 30$^{\circ}C$ was dissolved as the largest quantity of 11.874 mg/g at pH 1 and l5.93mg/g at pH 13, but dissolved the smallest quantity 1.75g/g at pH 5 as known. and tile quantity of crude protein treated for 60 minutes is 13.437mg/g at pH 1 and 22.50mg/g at pH 13. Also, the smallest quantity is 2. 813mg/g at pH 5 as known. 2. By the treatment during 30 minutes at 60$^{\circ}C$, the dissolved largest quantity was 13.12mg/g at pH 1 and 21.875 mg/g at pH 13, but the smallest quantity is 2.375mg/g at pH 5 as known After treatment for 60 minutes at 60$^{\circ}C$, the dissolved largest quantity was 17.500 mg/g at pH 1 and 31.56mg/g at pH 13, bu the smallest quantity is 3.849 mg/g at pH 5. 3. The dissolved crude protein from the cocoon shell and pupa by treatment for 30 minutes at 100${\pm}$2$^{\circ}C$ was the largest quantity of 147.000mg/g at pH 1 and 398. 125mg/g at pH 13, but the smallest quantity is 75.00mg/g at pH 5 as known. After treatment for 60 minutes at 100${\pm}$2$^{\circ}C$, the largest quantity was 253.76 mg/g at pH 1 and 460.625mg/g at pH 13, but the smallest quantity is 139.375mg/g at pH 5 as known. 4. The dissolved crude protein from the cocoon shell and pupa was not different in quantity by treatment at 30$^{\circ}C$ or 60$^{\circ}C$. But dissolved crude protein was large quantity from cocoon shell more than pupa, as known. 5. The treatment of cocoon shell and pupa during 60 minutes at 100${\pm}$20$^{\circ}C$ was increased to the dissolved largest quantity of crude protein of 19.20％ at pH 1 and 22. 18％ at pH 13 from the cocoon shell and 6. 12％ at pH, an d 23.87％ at pH 13 from the pupa. But dissolved crude protein was increased to the larger quantity from pupa more than cocoon shell.