• 제목/요약/키워드: $^{11}$B NMR

검색결과 121건 처리시간 0.023초

Conformations of Tetrahomodioxa-p0phenylcalix[4]arene Alkyl Ethers

  • No, Kwang-Hyun;Park, Young-Ja
    • Bulletin of the Korean Chemical Society
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    • 제23권11호
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    • pp.1629-1634
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    • 2002
  • Reaction of tetrahomodioxa p-phenylcalix[4]arene with alkyl halide and NaH in DMF leads to the title tetra-alkylated derivatives, 7,13,21,27-tetra-phenyl-29,30,31,32-tetraalkyloxy-2,3,16,17-tetrahomo-3,17-dioxacalix [4]arenes, their preferred conformations were determined by NMR spectra as C-1,2-alternate. The molecular structure of allyl derivative has been solved by X-ray diffraction methods. The molecules have a conformation with pseudo center of symmetry. The benzene ring A is up, ring C is down, B and D rings are flat with respect to the plane of the macrocyclic ring.

Some Pyridyl- and Thiophenyl-Substituted 1,2,4-Triazolo[3,4-b]1,3,4-thiadiazole Derivatives as Potent Antibacterial

  • Maqsood, Muhammad Rizwan;Hanif, Muhammad;Rafiq, Muhammad;Saleem, Muhammad;Zaib, Sumera;Khan, Aftab Ahmed;Iqbal, Mazhar;Iqbal, Jamshed;Rama, Nasim Hasan;Seo, Sung-Yum;Lee, Ki-Hwan
    • Bulletin of the Korean Chemical Society
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    • 제33권12호
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    • pp.4180-4184
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    • 2012
  • The target compounds 6-11a-e were synthesized by condensing 4-amino-5-aryl-3H-1,2,4-triazole-3-thiones 5a-f with various aromatic carboxylic acids in the presence of phosphorous oxychloride. The structures of newly synthesized compounds were characterized by IR, $^1H$ NMR, $^{13}C$ NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were screened for their antibacterial activity. Almost all the tested compounds were potent against four different strains of bacteria when compared with that of reference drug ciprofloxacin. Compounds 6c, 6e, 8d, 9b, 9e, 11a and 11b showed nearly equal or lower MIC values than standard drug, against all four tested bacterial strains but rest of the compounds showed excellent antibacterial activities.

Streptomyces luteogriseus KT-10 이 생산하는 Cathepsin B 저해물질의 분리 및 특성 (Isolation and Characterization of Cathepsin B inhilbitor Produced by Streptomyces luteogriseus KT-10)

  • 한길환;김상달
    • 한국미생물·생명공학회지
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    • 제29권2호
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    • pp.84-89
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    • 2001
  • 포유동물조직의 세포내에 존재하는 lysosomal cysteine계 cathepsin B 효소는 암 발병과 전이, 류머티스 관절염, 염증 및 노인성치매 등의 여러 질병에 관여하고 있다. 이 cathepsin B를 저해하는 저해물질이 Streptomyces luteogriseus KT-10에 의해 생산되어 분리되었다. S. luteogriseus KT-10이 생산하는 cathepsin B 저해물질은 열에 안정하며 산, 알칼리에도 안정한 물질로 구성되어 있다. Cathepsin B 저해물질은 DEAE-Sephadex A-25, Sephadex G-15, silica gel, Sephadex LH-20의 column chromatography 과정을 거친 후 분취용 HPLC를 이용 분취한 후 백색분말의 cathepsin B 저해물질을 정제하였다. 이 정제한 저해물질은 UV 상의 전 범위에서 특이한 검출부위를 확인할 수 없었으며, $H_2$O, methanol, ethanol, n-butanol에는 녹지만 비극성인 chloroform, n-hexane, benzene 등에는 불용성이었다. 또한 ninhydrine, $H_2$$SO_4$, iodine에 양성 반응이지만 Ehrlichs, Pauly, Sakaguchi, phthalic acid, DNS, aniline 등의 단백반응과 당 반응에는 음성 반응으로 나타났다. IR 기기에서는 OH 기와 CH 기의 peak를 확인하였으며 $^1$H NMR 기기로 OH peak와 NH peak 또한 확인할 수 있었다. $^{13}$ C NMR spectrum은 4개의 탄소 peak를 가진 물질로 확인된 분자량이 207 dalton인 저해물질이다. 원소 분석기를 이용한 저해물질 분석 결과 분자식이 $C_4$$H_{11}$ $O_4$$N_{6}$로 나타났다. 이 cathepsin B 저해물질의 저해양식은 competitive 저해로 작용함을 확인할 수 있었다.

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가시오가피(Acanthopanax senticosus)의 석유에테르 추출물 중 polyacetylene계 물질의 동정 (Identification of the Polyacetylenes extracted from Acanthopanax Senticosus by Petroleum Ether)

  • 양효진;김은미;장규섭
    • 농업과학연구
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    • 제35권1호
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    • pp.11-17
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    • 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.

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Complete $^1H$-NMR and $^{13}C$-NMR spectral analysis of the pairs of 20(S) and 20(R) ginsenosides

  • Yang, Heejung;Kim, Jeom Yong;Kim, Sun Ok;Yoo, Young Hyo;Sung, Sang Hyun
    • Journal of Ginseng Research
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    • 제38권3호
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    • pp.194-202
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    • 2014
  • Background: Ginsenosides, the major ingredients of Panax ginseng, have been studied for many decades in Asian countries as a result of their wide range of pharmacological properties. The less polar ginsenosides, with one or two sugar residues, are not present in nature and are produced during manufacturing processes by methods such as heating, steaming, acid hydrolysis, and enzyme reactions. $^1H$-NMR and $^{13}C$-NMR spectroscopic data for the identification of the less polar ginsenosides are often unavailable or incomplete. Methods: We isolated 21 compounds, including 10 pairs of 20(S) and 20(R) less polar ginsenosides (1-20), and an oleanane-type triterpene (21) from a processed ginseng preparation and obtained complete $^1H$-NMR and $^{13}C$-NMR spectroscopic data for the following compounds, referred to as compounds 1-21 for rapid identification: 20(S)-ginsenosides Rh2 (1), 20(R)-Rh2 (2), 20(S)-Rg3 (3), 20(R)-Rg3 (4), 6'-O-acetyl-20(S)-Rh2 [20(S)-AcetylRh2] (5), 20(R)-AcetylRh2 (6), 25-hydroxy-20(S)-Rh2 (7), 25-hydroxy-20(S)-Rh2 (8), 20(S)-Rh1 (9), 20(R)-Rh1 (10), 20(S)-Rg2 (11), 20(R)-Rg2 (12), 25-hydroxy-20(S)-Rh1 (13), 25-hydroxy-20(R)-Rh1 (14), 20(S)-AcetylRg2 (15), 20(R)-AcetylRg2 (16), Rh4 (17), Rg5 (18), Rk1 (19), 25-hydroxy-Rh4 (20), and oleanolic acid 28-O-b-D-glucopyranoside (21).

11B NMR 방법에 의한 SrO-B2O3-Al2O3와 SrO-B2O3-SiO2 유리들의 구조에 관한 연구 (Structure of SrO-B2O3-Al2O3 and SrO-B2O3-SiO2 glasses Using 11B Nuclear Magnetic Resonance)

  • 문성준
    • 한국안광학회지
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    • 제7권2호
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    • pp.19-25
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    • 2002
  • $SrO-B_2O_3$ 유리들에 같은 양의 $Al_2O_3$$SiO_2$를 첨가한 3성분 SrBAl 유리들과 SrBSi 유리들을 제작하여, $^{11}B$ NMR 방법을 이용하여 4배위 붕소 수인 $N_4$, 대칭적 3배위 붕소 수인 $N_{3S}$ 그리고 비대칭적 3배위 붕소 수인 $N_{3A}$를 얻어 구조를 정량적으로 비교 분석하였다. 두 유리 모두에 대해 $BO_3$ 단위의 경우 $Q_{cc}$=2.74MHz, ${\eta}=0.22$이며, $BO_3{^-}$단위의 경우 $Q_{cc}$=2.54MHz, ${\eta}=0.55$ 그리고 $BO_4$ 단위의 경우 $Q_{cc}$=0.60~0.75MHz, ${\eta}{\approx}0.00$이다. SrBAl 유리계에서는 $R_{1st}$($N_4$ 값의 제1변환점)에서의 유리들의 구조는 tetraborate ($[B_8O_{13}]^{-2}$) 단위들과 1차 변형된 diborate($[B_2Al_2O_7]^{-2}$) 단위들로 구성되어졌으며, $R_{max}$($N_4$ 최대인 R)에서 유리의 구조는 diborate($[B_4O_7]^{-2}$) 단위들, metaborate($[BO_2^{-1}]$) 단위들, 1차 변형된 diborate 단위들, 그리고 2차 변형된 diborate($[B_2Al_2O_8]^{-4}$) 단위들로 구성되어졌다. 그리고 3배위인 $AlO_3$ 단위들은 $BO_3$ 단위들보다 SrO로부터 도입된 산소를 우선적으로 배위하여 4배위인 $AlO_4$ 단위들로 전환되었다. 또한, SrBSi 유리계에서는 Si 원자들은 $R{\leq}0.5$ 영역에서는 붕소 망목구조에 기여하지 않으므로 유리 구조는 $SiO_4$ 단위들로 희석(diluted)된 2성분 SrB 유리계와 같은 구조로 구성되어졌으며, $R{\geq}R_{max}$이상의 영역에서는 SrO로부터 도입된 산소에 의해 $SiO_4$ 단위들이 $BO_3{^-}$ 단위들보다 우선적으로 $SiO_4{^-}$ 단위들로 모두 형성되었다. 그리고 $R_{max}$에서 유리의 구조는 diborate 단위들, metaborate 단위들, loose $BO_4([BO_2]^{-1})$ 단위들, 그리고 $SiO_4{^-}([SiO_{2.5}]^{-1})$ 단위들로 구성되어졌다.

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Structure elucidation of a newly isolated saponin from Clerodendrum serratum (L) Moon

  • Bhujbal, Santosh S.;K.Nanda, Rabindra;S.Deoda, Ramesh;Kumar, Dinesh;Kewatkar, Shailesh M.;S.More, Laxmikant;J.Patil, Manohar
    • Advances in Traditional Medicine
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    • 제10권4호
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    • pp.319-321
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    • 2010
  • Plant saponins are widely distributed amongst plants and have a wide range of biological properties. Icosahydropicenic acid, $C_{51}H_{80}O_{19}$ ((4S,6bS)-8a-((4,5-dihydroxy-6-methyl-3-((3R)-3,4,5-trihydroxy-6-methyl-tetrahydro-2H-pyran-2-yloxy)-tetrahydro-2H-pyran-2-yloxy)carbonyl)-2-hydroxy-4, 6a, 6b, 11, 14b-pentamethyl-11-(2-methylprop-1-enyl)-3-(3,4,5-trihydroxy-6-(hydroxymethyl) - tetrahydro-2Hpyran-2-yloxy)-1, 2, 3, 4, 4a, 5, 6, 6a, 6b, 7, 8, 8a, 9, 10, 11, 12, 12a, 14, 14a, 14b-icosahydropicene-4-carboxylic acid), a new saponin was first time isolated from the roots of Clerodendrum Serratum (L) Moon (Verbenaceae). The structure elucidation of the compound was carried out by $^1H$ NMR and DART-MS studies.

Solid state MAS NMR Investigation on the Local Structures of xV2O5-B2O3-yNa2O Glasses

  • Kim, Sun-Ha;Han, Oc-Hee;Kang, Jae-Pil;Song, Seung-Ki
    • Bulletin of the Korean Chemical Society
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    • 제30권3호
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    • pp.608-612
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    • 2009
  • The local structures of the boron and vanadium sites in the ternary glass $xV_2O_5-B_2O_3-yNa_2O$ were studied by $^{11}B\;and\;^{51}V$ magic angle spinning (MAS) nuclear magnetic resonance (NMR). With increasing x, the mole ratios of the $BO_3\;and\;BO_4$ structures were enhanced, as were the quadrupole asymmetry parameters for the $BO_3$ structures, while the quadrupole coupling constants for the sites were reduced. However, the opposite trends were observed with increasing y, implying that $V_2O_5$ and $Na_2O$ play opposite roles. The $VO_4,\;VO_5\;and\;VO_6$ structures with all oxygens bonded to the vanadium neighbors were identified. Vanadiums bonded to the greater number of oxygens were more populated at higher contents of $Na_2O\;and\;V_2O_5$. In addition, the $VO_4$ structures with at least one oxygen bonded to boron instead of vanadium were detected at low $Na_2O$ contents. The electron densities of various vanadium oxide structures were affected by the weight densities and vanadium ion densities. The $VO_4$ structures were more likely to be vanadium oxide structures right next to $V4^{+}$ ions.

Synthesis and Study of Antibacterial and Antifungal Activities of Novel 2-[[(Benzoxazole/benzimidazole-2-yl)sulfanyl]acetylamino]thiazoles

  • Kaplancikli, Zafer-Asim;Gulhan, Turan-Zitouni;Revial, Gilbert;Guven, Kiymet
    • Archives of Pharmacal Research
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    • 제27권11호
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    • pp.1081-1085
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    • 2004
  • Several 2-[[(benzoxazole/benzimidazole-2-yl)sulfanyl]acetylamino]thiazoles derivatives were synthesized by reacting 4-substituted-2-(chloroacetylamino)thiazoles with benzoxazole/benzimidazole-2-thioles in acetone and in the presence of $K_2CO_3$. The chemical structures of the compounds were elucidated by IR, $^1H-NMR$, and $FAB^{+}-MS$ spectral data. Their antimicrobial activities against Micrococcus luteus (NRLL B-4375), Bacillus cereus (NRRL B-3711), Proteus vulgaris (NRRL B-123), Salmonella typhimurium (NRRL B-4420), Staphylococcus aureus (NRRL B-767), Escherichia coli (NRRL B-3704), Candida albicans and Candida globrata (isolates obtained from Osmangazi Uni. Fac.of Medicine) were investigated and in this investigation, a significant level of activity was illustrated.

Structure of Three New Terpenoids, Spiciformisins a and b, and Monocyclosqualene, Isolated from the Herbs of Ligularia fischeri var. spiciformis and Cytotoxicity

  • Lee, Kyung-Tae;Koo, Sung-Ja;Jung, Seung-Hee;Choi, Jong-Won;Jung, Hyun-Ju;Park, Hee-Juhn
    • Archives of Pharmacal Research
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    • 제25권6호
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    • pp.820-823
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    • 2002
  • The diethylet er fraction from the leaves extract of Ligularia fischeri var. spiciformis (Compositae) was subjected to silica gel column chromatography and yielded three new terpenoids named spiciformisin a (1), spiciformisin b (3), and monocyclosqualene (2). Acyclic diterpenes, spiciformisin a and -b, were established as 3,7,11,15-tetramethyl-1,3(20)-hexadecadiene and 3,7,11,15-tetramethyl-1,3,6,10,14-hexadecapentaene (IUPAC), respectively. A monocyclic triterpene, monocyclosqualene, were determined as [3,8,12,16,16-pentamethyl-(3,7,11,15-hexadecatetraenyl)]-3,3,5-trimethyl-1-cyclohexene. The structures were determined on the basis of NMR and MS analysis. Spiciformicin b showed potent cytotoxicity ($IC_{50},{\;}<9.7{;\}{\mu\textrm{g}}/ml$ against HL-60) in contrast to no cytotoxicity ($IC_{50},{\;}>200{\;}}{\mu\textrm{g}}/ml against HL-60 cells) of spiciformicin a with a cis-conjugated dienyl diexomethylene.