• Natural Product Sciences
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• 제29권2호
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• pp.113-119
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• 2023

Descurainia sophia seeds methanol extract showed significant anti-influenza activity and we tried to isolate anti-influenza compounds from the D. sophia extract. D. sophia seeds were extracted with 80% methanol and fractionated with n-hexane, ethyl acetate, CHCl₃ and n-butanol. The anti-influenza activity of each fraction was assessed using sulforhodamine B (SRB) method in A549 cells, human-derived lung cancer cells. The ethyl acetate and CHCl₃ fractions showed the most potent anti-influenza activity. Seven compounds were isolated from CHCl₃ fraction and identified 1-decanol (1), 2-(3,4-dihydroxy-2-methylenebutoxy)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol (2), daucosterol (3), isorhamnetin (4), quercetin (5), sinapic acid (6), and helveticoside (7) by spectroscopic data such as UV, IR, ¹H-NMR, ¹³C-NMR and mass spectroscopy. Anti-influenza activities of isolated compounds were evaluated using SRB method in A549 cells. Compounds 3, 4 and 7 had significant anti-influenza activity in a dose-dependent manner.

• 분석과학
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• 제6권5호
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• pp.417-424
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• 1993

5,7-디클로로-8-히드록시퀴놀리놀(Hdcq)과 2-메르캅토피리미딘(Hmpd)를 포함하는 8-배위 테트라키스 몰리브데늄(IV) 착물을 합성하였다. $Mo(mpd)_4$, $Mo(dcq)(mpd)_3$, $Mo(dcq)_2(mpd)_2$, $Mo(dcq)_3(mpd)$와 $Mo(dcq)_4$ 착물들을 TLC plate에서 분리하였다. 이 착물들의 특성을 $^1H-nmr$ 스펙트럼과 자외선-가시광선 스펙트럼으로 조사하였다. 리간드의 질소원자에 대한 ${\alpha}$위치 양성자의 화학적 이동값은 낮은 장으로 이동되었으며, $Mo(dcq)(mpd)_3$와 $Mo(dcq)_3(mpd)$는 같은 위치의 양성자가 2:1의 상대적 세기로 나타났고 $Mo(dcq)_2(mpd)_2$는 거의 같은 세기였다. 이들 착물의 입체화학을 nmr 스펙트럼과 Orgel 규칙으로 고찰했다. 이 착물들의 전자전이 스펙트럼은 세기(${\varepsilon}$>10,000~25,000)와 낮은 에너지($16,600{\sim}19,800cm^{-1}$) 흡수띠를 관찰하여 이를 전하이동 흡수띠로 해석하였다.

• Journal of Magnetics
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• 제15권2호
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• pp.61-63
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• 2010

We used $^1H$ nuclear magnetic resonance (NMR) to study the phase transitions and molecular dynamics in a characteristic ferroelectric liquid crystal with a carbon number n = 7, S-2-methylbutyl 4-n-heptyloxybiphenyl-4'-carboxylate (C7). The results were compared with those of our recent work on S-2-methylbutyl 4-n-octanoyloxybiphenyl-4'-carboxylate (C8), with a carbon number n = 8. While the recrystallization and isotropic phase transitions exhibited a first-order nature in the $^1H$ NMR spin-lattice and spin-spin relaxation measurements, a second-order nature was shown at the Sm-A - Sm-$C^*$ liquid crystalline phase transition. A soft-mode anomaly arising from the tilt angle amplitude fluctuation of the director, of which only a hint had been noticed in the C8 system, was manifested in the C7 system at this transition.

• 생약학회지
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• 제9권1호
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• pp.1-9
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• 1978

The principle of Fourier Transform Nuclear Magnetic Resonance and its usefulness in the fields of pharmacy and biological sciences are described. 1. The $^1H\;and\;^{13}C$ NMR spectra of triostin A and its mixture with purine derivatives were taken. From the analysis of the spectra it has established that triostin A, which exists in two symmetric conformers in chloroform solution, forms complexes only with purine derivatives by the participation of one of the conformers. 2. Also, the $^{13}C$ NMR spectra of "intact" substances in the field of pharmacognosy were taken. From the spectra it was suggested that the method is very useful for natural product research in cooperation with the chemical method.

• 한국미생물·생명공학회지
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• 제28권2호
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• pp.71-79
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• 2000

Two typess of copolyesters, poly(3-hydroxybutyric acid-co-4-hydroxy-butyric acid)[P(3HB-co-4HB] and poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid)[P(3HB-co-3HV)], with various monomer ratios and different degree of microstructural heterogeneity were synthesized from Ralstonia eutropha H16 and Hydrogenophaga pseudoflava by using ${\gamma}$-butyrolactone and ${\gamma}$-valerolactone, respectively. The two bacteria showed a large difference in the utilization of ${\gamma}$-butyrolactone for cell growth and PHA synthesis. H. pseudoflava synthesized P(3HB-co-4HB) copolyesters with a wide range of 4HB content from 13 to 96 mol% depending on culture conditions, whiel R. eutropha H16 was able to synthesize the copolyesters containing less than 20 mol% of 4HB. An increase in the 4HB content in the P(3HB-co-4HB) copolyesters synthesized by H. pseud-oflava induced an lowering of their melting temperatures as well as their enthalpies of fusion. The increase in the 4HB content, however, increased the rate of degradation by an extracellular P(3HB) depolymerase. NMR spectros-copy and differential scanning calorimetry showed that the P(3HB-co-4HB) copolyesters from H. pseudoflava were generally microstructurally heterogeneous. The P(3HB-co-4HB) copolyesters) synthesized by R. eutropha H16 were rather random copolymers showing less microstructural heterogeneity than those synthesized by H. pseudoflava. The NMR D value analysis suggested that the monomer distribution of the P(3HB-co-3HV) copolymers from the two bacteria were relatively random.

• 대한화학회지
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• 제38권7호
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• pp.485-495
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• 1994

$[M(NO)_2Cl_2]_n(M = Mo, W)$을 출발물질로 사용하여 3단계 합성과정을 거쳐 $[Cl(dppp)(NO)_2M({\mu}-pyz)M'(NO)_2(dppp)Cl][ClO_4]_2$와 $[Cl(phen)(NO)_2M({\mu}-pyz)M'(NO)_2(dppp)Cl][ClO_4]_2$(M,M'= Mo or W; phen = 1,10-phenanthroline; dppp = 1,3-bis(diphenylphosphino)propane; pyz = 1,4-pyrazine) 형의 새로운 대칭 및 비대칭 이핵 착물을 합성하였다. 최종 생성물은 실리카겔 칼럼($2{\times}20$ cm)을 통해 아세톤으로 용리시켜 분리하였다. 합성한 착물은 원소분석과 적외선, 핵사기 공명 및 전자 흡수스펙트럼 등을 이용해서 그 특성을 조사하였다. 적외선 스펙트럼은 모든 착물이 팔면체 구조로서 두 개의 NO기가 cis 위치로 배위되어 있음을 나타냈으며, $^1H$ 및 $^{13}C$ 핵자기 공명 스펙트럼은 이들 착물이 pyz가 다리결합하고 있는 이핵 착물임을 나타내었다.

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1445-1449
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• 2006

Molecular tweezers based on chenodeoxycholic acid bearing different lengths of arm were synthesized andtheir anion binding affinities were evaluated by $^1H$ NMR, isothermal calorimetric titration, and ESI mass spectrometry. Molecular tweezer 6 showed a high selectivity toward $H_2PO_4\;^-$ over $Cl^-,\;Br^-,\;I^-, $ and $CH_3CO_2\;^-$ by $^1H$ NMR titration, whereas the association constant for $F^-$ revealed the largest value as determined by ITC. The selectivity of 6 towards $F^-$ was about 103 times higher than that of $Cl^-,\;H_2PO_4\;^- $, and $CH_3CO_2\;^-$. ITCexperiment of 6 with $F^-$ in a DMSO showed two binding modes; two sequential association constants $K_1\;=\;2.77\;{\times}\;10^5\;M^{-1}$ and $K_2\;=\;8.68\;{\times}\;10^6\;M^{-1}$ were found. These sequential bindings were confirmed by ESI massspectrometry. 1 : 1 and 1 : 2 complexes of 6 and $F^-$ were found at m/z 868.08 and 884.04.

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.849-852
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• 2009

The work describes EPR and 17O NMR measurements followed by theoretical calculation of the rotational correlation time $({\tau}_R)$, the water residence time $({\tau}_m)$, and the longitudinal electronic spin relaxation time $(T_{le})$(T_1e) for two new gadolinium complexes 1 and 2 of the type [$Gd(L)(H_2O)$] (L = tranexamic esters) in order to investigate their efficiency as a paramagnetic contrast agent (PCA). Of three correlation times, τR plays a major and predominant role to the unusually high relaxivity of 1 and 2 as compared with that of clinically approved MR CAs such as [$Gd(DTPA)(H_2O)]2‐ (Magnevist${\circledR}$), [Gd(DTPA-BMA)(H2O)] (Omniscan${\circledR}$), and $[Gd(DOTA)(H_2O)]^-$ (Dotarem${\circledR}$). The presence of bulky tranexamic ester in the ligand seems to be responsible for the conformational rigidity, which in turn causes such great an increase in ${\tau}_R$.

• Macromolecular Research
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• 제17권12호
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• pp.1003-1009
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• 2009

Copolymers of N-vinylpyrrolidone (NVP) comonomer with styrene (St), hydroxypropyl methacrylate (HPMA) and carboxyphenyl maleimide (CPMI) were synthesized by free radical polymerization using 2,2'-azobisisobutyronitrile (AIBN) initiator in 1,4-dioxane solvent. The copolymers formed were characterized by FTIR, $^1H$ NMR and $^{13}C$ NMR techniques and their thermal properties were studied by DSC and TGA. Copolymer composition was determined by $^1H$ NMR and/or by elemental analysis and monomer reactivity ratios (MRR) were estimated by the linear methods of Kelen-Tudos (K-T) and extended Kelen-Tudos (EK-T) and the non-linear approach. Copolymers of St and HPMA with NVP formed blocks of one of the monomer units, whereas alternating copolymers were obtained in CPMI-NVP, depending upon the side chain substitution. The MRR values are discussed in terms of monomer structural properties such as electronegativity and electron delocalization. The sequence distribution of monomers in the copolymers was studied by statistical method based on the average reactivity ratios obtained by EK-T method.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 춘계학술대회
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• pp.67-67
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• 1995

Acyl-CoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26) plays an important role in the control of intracellular free cholesterol content via its cholesterol esterifying activity. ACAT inhibitors are expected to be effective for treatment of atherosclerosis and hypercholesterolemia. In the course of a screening program for ACAT inhibitors from microbial sources, GERI-BP001 M, A, and B were isolated from the fermentation broth of a fungal strain. GERI-BP001 compounds were isolated from a culture broth of Aspergillus fumigatus F37 by acetone extraction, EtOAc extraction, SiO$_2$ column chromatography, and reverse phase HPLC. The structure of GERI-BP001 coumpounds were determined by $^1$H-NMR, $\^$l3/C-NMR, 2D-NMR, NOESY, and long range C-H COSY experiments. GERI-BP001 M, A, and B inhibit ACAT activity in an enzyme assay system using rat liver microsomes by 50% at concentrations of 75, 147, and 71 ${\mu}$M, respectively.