• 농업과학연구
• /
• 제35권1호
• /
• pp.11-17
• /
• 2008

가시오가피를 실온에서 petroleum ether로 추출한 polyacetylene의 동정하기 위하여 TLC, HPLC, UV spectrum, IR, NMR로 수행하였다. TLC에 전개시킨 결과, polyacetylene 표준품과 동일한 band가 fraction 5에서 확인되었으며, HPLC에서 fraction 5를 분리시킨 결과 retention time이 4.40, 5.36, 6.40분이었다. 이를 UV spectrum에서 확인한 결과, 6.40분의 peak(compound 3)에서 polyacetylenes의 파장인 231.0nm, 239.0nm, 257.0nm을 나타내었다. IR spetrum에서 triple bond $2256cm^{-1}$과 double bond $1654cm^{-1}$의 전형적인 peak를 나타내었으며, $^{13}C$-NMR(400MHz, $CDCl_3$)에서 polyacetylenes 전형적인 64.0, 71.2, 74.2, 80.2ppm은 2개의 triple bond에 의한 peak와 121.89, 133.0ppm에서 internal double bond로 결합된 2개의 peak를 확인 할 수 있었다.

• Applied Biological Chemistry
• /
• 제36권2호
• /
• pp.134-137
• /
• 1993

우리나라 전지역의 산과 들에 야생하고 있는 고들빼기(Youngia sonchifolia Max.)는 전통식품인 고들빼기 김치의 원료로 이용될 뿐만 아니라 오래전부터 민간에서 위장장애 치료재로 이용되어 왔다. 그래서 고들빼기의 생화학적 활성 및 항암 실험과 그 특수성분을 분석하였는데 hexane 추출물 중에서 silica gel column chromatography와 재결정으로 얻어낸 화합물은 무색판상 결정으로 융점이 $280{\sim}282^{\circ}C$ 이었으며 구조결정을 위해 $^{13}C-NMR$, $^1H-NMR$, MS로 분석한 결과 pentacyclic triterpene인 bauerenyl acetate인 것을 확인하였다.

• 한국자기공명학회논문지
• /
• 제20권2호
• /
• pp.50-55
• /
• 2016

Backbone $^1H$, $^{13}C$ and $^{15}N$ resonance assignments are presented for the anticodon binding domain (residues 557-674) of human glycyl-tRNA synthetase (GRS). Role of the anticodon binding domain (ABD) of GRS as an anticancer ligand has recently been reported and its role in other diseases like Charcot-Marie-Tooth (CMT) and polymyositis have increased its interest. NMR assignments were completed using the isotope [$^{13}C/^{15}N$]-enriched protein and chemical shifts based secondary structure analysis with TALOS+ demonstrate similar secondary structure as reported in X-ray structure PDB 2ZT8, except some C-terminal residues. NMR signals from the N-terminal residues 557 to 571 and 590 to 614 showed very weak or no signals exhibiting dynamics or conformational exchange in NMR timescale.

• 분석과학
• /
• 제13권1호
• /
• pp.49-54
• /
• 2000

5단계 반응을 통하여 실리카겔의 8-hydroxyquinoline 유도체를 제조하였으며, 각 단계에서 얻은 생성물들을 IR과 NMR을 이용하여 분석하였다. 실리카겔 자체에 관한 IR 스펙트럼으로부터, 자유 hydroxyl기와 수소 결합된 hydroxyl기가 존재하는 것을 확인할 수 있었다. 첫 단계 반응에서는 N-H와 C-H의 IR 밴드와 APTS기에 있는 메틸렌 탄소의 NMR peak을 확인하였다. 둘째 단계에서는 카보닐, nitro, 방향족 탄소의 IR 밴드와 지방족, 방향족, 카보닐 탄소의 NMR peak을 관찰하였으며, 셋째 단계에서 $NO_2$가 $NH_2$로 환원되는 것을 IR과 NMR로 확인할 수 있었다. 마지막 단계에서는 4번째 단계에서 생성된 $N{\equiv}N$ IR peak이 사라지는 것으로부터 8-quinolinol이 고정화되는 것을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
• /
• 제10권6호
• /
• pp.591-595
• /
• 1989

The$^{13}C$ NMR shifts of a series of para-substituted 9-aryl-tricyclo$[3.3.1.0^{2,8}]$non-9-yl and 8-aryl-tetracyclo$[3.2.1.0^{2,7}.0^{4,6}]$-oct-8-yl cations were measured in $FSO_3H/SO_2ClF \;at\; -90^{\circ}C\; or\; -70^{\circ}C$ in order to examine whether the ${\rho}^{c+}$ values can be used to explain the mechanism for the stabilization of the geometrically rigid cyclopropylcarbinyl cations. Plots of the ${\Delta}{\delta}^{c+}$ shifts against ${\sigma}^{c+}$ reveal excellent linear correlation. The tricyclononyl systems yield a ${\rho}^{c+}$ value of -4.95 with a correlation coefficient r = 0.9948. The tetracyclo-octanyl systems give a ${\rho}^{c+}$ value of -6.39 with r = 0.9943. A fair parallelism exists between the results of $^{19}F$ nmr studies and the change of ${\rho}^{c+}$ values in these cations. Accordingly, the present study established that the ${\rho}^{c+}$ value can be used as a mearsure of the geometric influence for the charge delocalization in cyclopropylcarbinyl cations.

• 한국결정학회지
• /
• 제13권2호
• /
• pp.82-85
• /
• 2002

cis,cis,trans-[MoBr/sub 2/(CO)/sub 2/(PPh/sub 3/)/sub 2/］와 2,6-dimethylphenyl isocyanide의 반응으로부터 화합물cis,fac-[Mo(O)Br/sub 2/,(CN-C/sub 6/H/sub 3/,-2,6-Me/sub 2/)sub 3/] (1)이 분리되었다. 화합물 1의 구조가 분광학적 방법(/sup 1/H-NMR, /sup 13/C｛/sup 1/H｝-NMR, IR) 및 X-ray 회절법으로 규명되었다. 화합물 1의 결정학 자료: 삼사정계 공 간군 P(equation omitted), a=9.172(2) (equation omitted), b ＝ 11.550(3) (equation omitted), c ＝ 15.106(3) (equation omitted), α ＝ 100.44(2)°, β＝ 107.12(2)°, γ＝ 107.83(1)°, Z ＝ 2, R(wR/sub 2/) ＝ 0.0529(0.1344).

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

• Bulletin of the Korean Chemical Society
• /
• 제12권2호
• /
• pp.193-196
• /
• 1991

The $^{13}C-NMR$ shifts of a series of para-substituted $8-aryl-tricyclo[3.2.1.0^{2,7}]oct-8-yl$ and $9-aryl-tricyclo[3.3.1.0^{2,8}]-non-9-yl$ cations were measured in $FSO_3H/SO_2ClF\ at\-90^{\circ}$ in order to examine whether the ${\rho}^{C^+}$ values can be used as a measure of the geometric influence on the charge delocalization resulting from ${\rho}$ conjugation in rigid tricyclopropylcarbinyl cations. Plot of the ${\Delta}{\delta}^{C+} shifts against the ${\sigma}^{C+}$ constants revealed excellent linear correlation. The 8-aryl tricyclooctyl systems yielded a ${\rho}^{C+}$ value of -5.00 with r = 0.9962. Previous investigation of the 9-aryl-tricyclononyl systems gave a correlation coefficient of r = 0.9948 with a slope of ${\rho}^{C+}$ = -4.95. A fair parallelism exists between the results of $^{19}F-NMR $ studies and the change of ${\rho}^{C+}$ value in these cations. Consequently, it is established that the ${\rho}^{C+}$ value can be used to explain the mechanism of charge stabilization of the rigid cyclopropylcarbinyl cation such as tricyclo $[3.2.1.0^{2,7}]oct-8-yl$ cation.

• Korean Chemical Engineering Research
• /
• 제43권1호
• /
• pp.71-75
• /
• 2005

초거대 자기 저항 물질인 $La_{0.5}Ca_{0.5}MnO_3$의 분말과 pellet을 졸-겔 법으로 제조하였다. 열처리 온도를 변화시켜 얻은 시료에 대해 FT-IR과 CP/MAS $^{13}C$ solid state NMR spectroscopy 그리고 XRD 등을 이용해 구조변화를 관찰하였다. 양이온 조성 비율을 알아보기 위해 ICP-AES를 이용하였으며, 입자크기와 균일도를 FE-SEM/EDS로, 미세구조와 격자 패턴은 TEM으로 관찰하였다. VSM을 이용하여 자기적 특성을 살펴보았으며 큐리온도($T_c$)는 236 K에서 측정되었다.

• Bulletin of the Korean Chemical Society
• /
• 제29권2호
• /
• pp.405-407
• /
• 2008

Functionalized SAB-15 samples by octadecyltrimethoxysilane (OTC) were studied by 13C magic angle spinning (MAS) cross polarization (CP) nuclear magnetic resonance (NMR) spectroscopy. In the SBA-15 sample fully functionalized by 3-aminopropyltrimethoxysilane (APS) and OTC in 1:1 molar ratio, octadecyl chains were observed to have, on average, more trans conformation than those in the SBA-15 samples fully modified by OTC only. Our results confirm that long chain molecules tend to organize themselves better in the co-presence of short chain molecules on the surface of mesoporous materials by packing of the different length chains in an interdigitized fashion even when the short chains are long enough to have three carbons and a functional group at the ends. In addition, our results indicate that solid-state 13C CP MAS NMR spectroscopy is a simple and non-destructive method to probe the molecular structures of the domains composed of long alkyl chains.