• 펄프종이기술
• /
• 제45권1호
• /
• pp.27-34
• /
• 2013

Quantitative analysis of 5-hydroxymethylfufural (5-HMF) conversion from fructose by dehydration and rearrangement was investigated by $^1H$-NMR spectroscopic method. Fructose was converted to 5-HMF in dimethylsulfoxide (DMSO)-$d^6$ or acidic deuterium hydroxide at controlled reaction temperature and time. With addition of internal standards (biphenyl for DMSO-$d^6$ solvent, and 2,5-dihydroxybenzoic acid for deuterium oxide solvent), conversion from fructose to 5-HMF was analyzed by $^1H$-NMR spectroscopy. Quantitative analysis was run by comparison with peak area integration between of 5-HMF and internal standard. In DMSO solvent, 5-HMF was stable end product but part of 5-HMF was converted to formic and levulinic acid at acidic aqueous medium.

• 공업화학
• /
• 제33권3호
• /
• pp.302-308
• /
• 2022

사격장 피탄지에 잔류되는 고폭화약으로 인한 환경오염 문제를 해결하기 위해 표면적이 큰 나노입자를 사용한 분해반응을 연구하였다. 수질오염을 가상하여 물에 용해시킨 research department explosive (RDX)와 high melting explosive(HMX) 니트라민 폭발물에 PdO를 첨가하여 313 K에서 분해반응시켰다. 폭발물의 분해반응속도를 측정하기 위해 반응 초기부터 종료시까지 시료 손실없이 반응속도를 측정할 수 있고 스펙트럼을 통하여 반응의 진행 정도를 관찰 가능한 ¹H NMR을 사용하였다. NMR 피크의 chemical shift 및 peak intensity 분석으로 유사 1차 분해반응이 일어남을 확인하였으며, 측정된 RDX와 HMX의 분해반응 속도상수는 각각 2.10 × 10^-2과 6.35 × 10^-4 h^-1이었다. 본 연구로부터 산화금속 PdO 나노입자는 니트라민 폭발물 분해반응연구에 적용 가능함을 확인하였다.

• 한국식품영양학회지
• /
• 제16권1호
• /
• pp.60-65
• /
• 2003

옻나무(Rhus verniciflua)는 한국에서 위장병, 변비, 어혈, 구충 등에 효과가 있다고 알려져 있어 민간요법과 보양식품으로 옻닭으로 식용하고 있으나 독성(allergy, 옻 오름)이 심각하여 주의를 요하는 식품이다. 옻의 독성 제거방법을 사용하여 옻나무 껍질을 물로 추출한 후 항산화 작용을 갖는 수용성 물질을 분리하여 물리, 화학적 특성과 기기 분석을 통하여 (UV, IR, EI (HR)-MS, $^1$H-NMR, $^{13}$C-NMR, elemental analyzer) 구조 분석한 결과 gallic acid (3,4,5-hydroxylbenzoic acid) 임을 확인하였다.

• Natural Product Sciences
• /
• 제4권4호
• /
• pp.221-225
• /
• 1998

A novel flavonol trisulphate, quercetin 7-methyl ether $3,3',4'-tri-O-KSO_3$ was isolated from the fresh leaves of Tamarix amplexicaulis (Tamaricaceae) along with the known flavonol mono sulphates, quercetin $3-O-KSO_3$ and quercetin 4'-methyl ether $3-O-KSO_3$. Structures were achieved through conventional analytical methods, including electrophoretic analysis and confirmed by FAB-MS and NMR spectroscopy.

• 미생물학회지
• /
• 제27권1호
• /
• pp.35-42
• /
• 1989

The mode of transglycosylation reaction observed during the action of low-molecular-weigh $\beta$-D-glucosidase ($\beta$-D-glucoside glucohydrolase, EC3.2.1.21) purified from Trichoderma koningii ATCC 26113 was investigated using $^{1}H$-NMR spectroscopy. The enzyme was purified by the series of procedures including ammonium sulfate precipitation, and fractionations by column chromatographies on Bio-Gel P-150, DEAE-Sephadex A-50, and SP-Sephadex C-50. The final purification was performed by the band eluation after preparative polyacrylamide gel electrophoresis. The enzyme showed its molecular size of 78,000 through the analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and its isoelectric point of 5.80 through the analysis of analytical isoelectric focusing. The H-1 proton resonances were analyzed. After the reaction of the enzyme with cellobiose, the reaction products were separated by high performance liquid chromatography using refractive index detector. H-1 resonances of the products were consisted with those of gentiobiose [$\beta$-D-glucopyranosyl--(1,6)-D-glucopyranose], and cellotriose [$\beta$-D glucopyranosyl-(1,4)-$\beta$-D-glucopyranosyl]-(1,4)-D-glucopyranose] with minor resonances of sophorose [$\beta$-D-glucopyranosyl-(1,2)-D-glucopyranose], respectively.

• Macromolecular Research
• /
• 제13권5호
• /
• pp.373-384
• /
• 2005

Novel pH-sensitive moieties containing an s-triazine ring were synthesized with sulfonamide and secondary amino groups. The synthesized pH-sensitive moieties were used for the synthesis of a pH-sensitive amphiphilic ABA triblock copolymer. The pH-sensitive triblock copolymer was composed of diblock copolymers, methoxy poly(ethylene glycol)-poly ($\varepsilon$-caprolactone-co-D,L-lactide) (MPEG-PCLA), and pH-sensitive moiety. These copolymers could be dissolved molecularly in both acidic and basic aqueous media at room temperature due to secondary amino and sulfonamide groups. The synthesized s-triazine rings containing pH-sensitive compounds were characterized by ${^1}H-NMR,\;{^13}C-NMR$, and LC/MSD spectral data. The synthesized diblock and triblock copolymers were also characterized by ${^1}H-NMR$ and GPC analyses. The critical micelle concentrations at various pH conditions were determined by fluorescence technique using pyrene as a probe. Furthermore, the micellization and demicellization study of the triblock copolymer was done with pH-sensitive groups. The sensitivity towards pH change was further established by acid-base titration.

• 한국약용작물학회지
• /
• 제12권3호
• /
• pp.203-208
• /
• 2004

참돌꽃의 캘러스는 0.5 mg/l NAA와 1 mg/l BA가 조합 첨가된 1/2MS 배지에서 유도하였으며, 현탁세포배양은 0.5 mg/l NAA와 1 mg/l BA가 조합 첨가된 2B5 배지에서 확립되었다. 한편, 참돌꽃 뿌리로부터 반복된 silicagel colum chromatography와 분취 HPLC를 통하여 순수한 salidroside 결정을 얻었으며, 얻어진 결정체는 $^1H-NMR,\;^{13}C-NMR$ 및 $^1H-^1H$ COSY 등의 분광학적 분석으로 구조를 동정 확인하였다. 확립된 세포배양계에서 salidroside 함량은 원뿌리 0.17%에 비교하여 광배양(0.12%) 암배양 (0.286%) 및 sucrose 5%에서 함량이 0.41% 까지의 함량변화를 나타내었다.

• Bulletin of the Korean Chemical Society
• /
• 제35권9호
• /
• pp.2753-2757
• /
• 2014

INtegrase Interactor 1 protein (INI1/hSNF5) or BRG1-associated factor 47 (BAF47) is a SWI/SNF-related matrix associated actin dependent regulator of chromatin subfamily B member. DNA binding domain of INI1/hSNF5 is cloned into E.coli expression vectors, pET32a and purified as a monomer using size exclusion chromatography. NMR data show that $INI1^{DBD}$ has folded state with high population of ${\alpha}$-helices. By fluorescence-quenching experiments, binding affinities between $INI1^{DBD}$ and two double stranded DNA fragments were determined as $29.9{\pm}2.6{\mu}M$ (GAL4_1) and $258.7{\pm}5.8$ (GAL4_2) ${\mu}M$, respectively. Our data revealed that DNA binding domain of INI1/hSNF5 binds to transcriptional DNA sequences, and it could play an important role as a transcriptional regulator.

• 한국자기공명학회논문지
• /
• 제17권1호
• /
• pp.40-46
• /
• 2013

For a case study of suspected paraquat intoxication, we developed a simple and rapid method of $^1H$ qNMR to determine the mili-molar amount of paraquat in postmortem blood samples. There were no interfering signals from endogenous compounds in the chemical shift of paraquat and diquat (internal standard). The amount of sample used ranged from 0.25 mM to 10.0 mM. Diquat, which has similar physicochemical properties with paraquat, was chosen as an internal standard. The NMR experimental conditions, relaxation delay time and CPMG spin-echo pulse sequence were optimized. The developed method was validated in terms of specificity, accuracy, precision, matrix effect, recovery, limit of detection (LOD), and low limit of quantification (LLOQ). The proposed qNMR method provided a simple and rapid assay for the identification and quantification of the quaternary ammonium herbicide, "paraquat" in postmortem blood samples. This method was tested by using the blood from the heart of a man who was intoxicated with paraquat. In this particular case, the level of paraquat was 1.07 mM in the blood. For the determination of quaternary ammonium herbicides, qNMR could also be used to provide a better understanding of the currently available techniques.

• Journal of the Korean Wood Science and Technology
• /
• 제37권1호
• /
• pp.114-120
• /
• 2009

현사시나무 수피를 채취하여 기건 시킨 후 70% 아세톤 용액으로 추출하고 농축한 후 헥산, 디클로로메탄, 에틸아세테이트 및 수용성으로 순차 추출하여 동결건조하였다. 에틸아세테이트 분획에 대하여 Sephadex LH-20 컬럼크로마토그래피와 분취 TLC를 반복적으로 수행하여 화합물을 분리하였다. 화합물의 구조는 산 가수분해와 $^1H$-NMR, $^{13}C$-NMR, 2D-NMR 및 MALDI TOF-MS 스펙트럼을 분석하여, grandidentatin A(cis-2-hydroxycyclohexyl 6-O-p-coumaroyl-${\beta}$-D-glucopyranoside)로 동정하였다. Grandidentatin A는 현사시나무 수피에서 처음 분리되었으며, 문헌에 보고되지 않은 신규화합물이다.