• Title/Summary/Keyword: structure elucidation

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Synthesis and Antifungal Activities of Some Aryl (3-Methyl-Benzofuran-2-yl) Ketoximes

  • Benkli, Kadriye;Gundogdu-Karaburun, Nalan;Karaburun, Ahmet-Cagrl;Ucucu, Umit;Demirayak, Seref;Kiraz, Nuri
    • Archives of Pharmacal Research
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    • v.26 no.3
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    • pp.202-206
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    • 2003
  • In this study, some aryl (3-methyl-benzofuran-2-yl) ketoximes and their ethers and esters were synthesised. The structure elucidation of the compounds was performed by IR, $^1H-NMR$, MASS spectroscopy and elemental analyses. Antifungal activities of the compounds were examined and moderate activity was obtained.

Supramolecular Nanomaterials Derived from Self-Assembly of Dendritic Building Blocks

  • Park, Chi-Young;Lee, Sang-Wha;Lim, Ji-No;Lim, Moon-Seob;Kim, Chul-Hee
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.91-92
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    • 2006
  • The fine-tuned dendrons provide unique supramolecular self-assemblies in various environments such as in water, organic media, and solid-liquid interfaces. They form nanotubes, vesicles, thin films, columns, lamellar nanoribbons depending on the condition of self-assembly process. Unique characteristics of self-assembly of the amide dendrons are described. In addition, elucidation of the structural correlation between the building blocks and the assemblies, stabilization of assembled structure, and transformation of supramolecular assemblies by using external stimuli. Particular emphasis is placed on the formation of cyclodextrin-covered organic nanotubes derived from self-assembly of amide dendrons and their supramolecular transformation. Finally, unique biosensory characteristics of the self-assembled nanotubes will be discussed.

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New Strategy for the Synthesis of 5-Aryl-1H,1'H-spiro[furo[2,3-d]pyrimidine-6,5'-pyrimidine]2,2',4,4',6'(3H,3'H,5H)-pentaones and Their Sulfur Analogues

  • Jalilzadeh, Mohammad;Pesyan, Nader Noroozi
    • Bulletin of the Korean Chemical Society
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    • v.32 no.9
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    • pp.3382-3388
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    • 2011
  • Reaction of barbituric acid (BA), 1,3-dimethyl barbituric acid (DMBA) and 2-thiobarbituric acid (TBA) with cyanogen bromide and aldehydes in the presence of L-(+)-tartaric acid afforded a new route for the synthesis of stable heterocyclic 5-aryl-1H,1'H-spiro[furo[2,3-d]pyrimidine-6,5'-pyrimidine]2,2',4,4',6'(3H,3'H,5H)-pentaones which is a dimeric form of barbiturate (uracil and thiouracil derivative). In the reaction of 1,3-diethyl thiobarbituric acid (DETBA) the Knoevenagel condensation and then Michael adducts were obtained under the same condition. Structure elucidation is carried out by $^1H$ NMR, $^{13}C$ NMR, FT-IR and Mass analyses. Mechanism of the formation is discussed.

Terpenoids from Two Sponge Species of the Aegean Sea

  • Erdogan, Ilkay;Tanaka, Junichi;Higa, Tatsuo;Sener, Bilge
    • Natural Product Sciences
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    • v.5 no.4
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    • pp.177-180
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    • 1999
  • The ethanolic extracts of two shallow water sponge species collected from the Aegean Sea afforded thirteen terpenoids in total, two of which were determined to be new. The structure elucidation of the terpenoids was carried out by spectroscopic techniques and comparison with related authentic compounds. The terpenoids have also been assayed for antibacterial activity. This is the first report about the metabolites isolated from the marine sponges of the Aegean Sea in Turkey.

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Mass Spectrometry of Dammarane Triterpenoids (Dammarane계(係) Triterpenoid의 질량분광분석(質量分光分析))

  • Han, Byung-Hoon;Kim, Jae-Hoon;Chi, Hyung-Joon
    • Korean Journal of Pharmacognosy
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    • v.10 no.2
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    • pp.55-59
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    • 1979
  • Mass spectra of the dammarane triterpenes having open side chain and $C_{20}-C_{25}-epoxy$ side chain were measured. Principal fragment ions were assigned and plausible mechanisms for the formation of the fragment ions were proposed. In general, the triter-penoids of $C_{20}-C_{25}-epoxy$ side chain. produce $h_{1}-species$ fragment ions by the deletion of side chain at $C_{20}-C_{22}$ bond and open side chain triterpenoids produce $h_{2}$ species fragmentions whose mass numbers are higher by two mass unit than those of $h_{1}$ species. The mass number of h species fragment ions will serve as the diagnostic tool for the elucidation of side chain structure of tetracyclic triterpenoids.

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Isolation and structure elucidation of a catechin glycoside with phospholipase $A_2$ inhibiting activity from Ulmi cortex

  • Park, Sunghyouk;Goo, Yang-Mo
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1995.04a
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    • pp.58-58
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    • 1995
  • 식물에서부터 새로운 소염작용제를 개발하기 위하여 여러식물을 대상으로 염증반응의 초기단계에서 중요한 역할을 하는 것으로 알려진 Phospholipase $A_2$에 저해활성을 갖는 물질을 검색하였고 그 중 강한 억제활성을 보인 유근피에서 유효성분을 분리하였다. 유근피의 에칠 아세테이트 분획에 대하여 실리카겔 크로마토그래피, Sephadex LH-20 크로마토그래피, 분취 박막 크로마토그래피를 수행하여 phenol성 -OH기를 갖는 활성성분인 PSH-II-84-1를 분리하였다. $^1$H-NMR 신호의 양상과 짝지움 상수 값에서 분리된 물질은 (+)-catechin 의 당 유도체로 확인되었다. $^{13}$C-NMR 자료를 분석하여 치환된 당은 D-apiofuranose로 확인되었다. 방향족환의 $^{l3}$C-NMR 신호들은 extended Huekel theory를 응용하여 얻은 net charge 계산 값과 상관시켜 할당하였다. 이상의 구조연구 결과 이 물질은 (+)-catechin-7-0-$\beta$-D-apiofuranoside로 밝혀졌다. (+)-catechin-7-0-$\beta$-D-apiofuranoside의 효소억제활성은 Type II Phospholipase $A_2$에 대하여 $IC_{50}$/이 600$\mu$M이었다.다.

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Structure Elucidation of Analgesic Constituents from Yerba Buena Leaves

  • Canlas, Arlyn P.
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.169-169
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    • 1998
  • Three analgesic constituents: FB2c, FB6Fc, and FB10E5c from the hexane extract of Mentha cordifolia Opiz. (Yerba buena) leaves were isolated by solvent partitioning and sequential repeated vacuum liquid chromatography. Spectral analysis of the three constituents show that FB2c is ${\beta}$-sitosterol; FB10E5c is ${\beta}$-sitosteryl-${\beta}$-D-glucopyranoside; and FB6Fc is a cis-8- pentadecenyl with lactone variety. At a dosage of 100 mg/kg mouse, isolates FB2c, FB6Fc, and FB10E5c decreased the number of squirms induces by acetic acid by 70.0 %, 67.3 %, and 73.0 %, respectively.

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Isolation and Structure Elucidation of Acyl CoA Synthetase Inhibitor from Bacilus sp. B-6 (Bacillus sp. B-6가 생산하는 acyl CoA 합성 효소 억제 물질의 분리 및 구조 결정)

  • Kim, Kyoung-Ja;Kim, Tae-Kyong
    • YAKHAK HOEJI
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    • v.42 no.6
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    • pp.552-557
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    • 1998
  • Acyl CoA synthetase inhibitor, was purified from the culture broth of a Bacillus sp. B-6, which had been isolated from soil, by chloroform extract, silica gel column chro matography and preparative TLC. The purified acyl CoA synthetase inhibitor showed higher Antifungal activity against C. al-bicans (MIC: 8${\mu}$g/ml). Though the analysis of UV spectrum, melting point, IR spectrum, Mass-spectrum, $^1H$-NMR and $^{13}C$-NMR spectrum, the inhibitor could be identified as phenazine-l-carboxylic acid.

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Bioactive secondary metabolites produced by fungi

  • Shim, Sang Hee
    • 한국균학회소식:학술대회논문집
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    • 2018.05a
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    • pp.49-49
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    • 2018
  • A variety of bioactive secondary metabolites have been reported from plant-associated microorganisms. Halophytes, plants that can only grow in hypersaline area, were reported to host beneficial microorganisms such as plant growth-promoting endophytes. The microorganisms have been reported to show notable mutualistic symbiosis with halophytes to help them survive in high saline condition. Finding out bioactive secondary metabolites as well as elucidation of relationship(s) between microbes and the host halophyte has been paid attention, because of their functional diversity. Novel microbes often have associated with novel natural products. In an effort to investigate natural compounds with interesting structures from fungi, we selected plants from a distinct environmental setting which could be a promising source. Several fungi were isolated from halophyte or medicinal plants. Some strains of the fungi were cultivated on a large scale and extracted with ethyl acetate, which were subjected to a series of chromatographic methods, leading to the isolation of tens of compounds. The isolated compounds were identified by analysis of spectroscopic methods such as 1D-, 2D-NMR, and MS. Details of isolation, structure determination, and biological activities will be discussed.

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Thermodynamic Elucidation of Binding Isotherms for Hemoglobin & Globin of Human and Bovine upon Interaction with Dodecyl Trimethyl Ammonium Bromide

  • Bordbar, A.K.;Nasehzadeh, A.;Ajloo, D.;Omidiyan, K.;Naghibi, H.;Mehrabi, M.;Khajehpour, H.;Rezaei-Tavirani, M.;Moosavi-Movahedi, A.A.
    • Bulletin of the Korean Chemical Society
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    • v.23 no.8
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    • pp.1073-1077
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    • 2002
  • Binding of dodecyl trimethylammonium bromide (DTAB) to human and bovine hemoglobin and globin samples has been investigated in 50 mM glycine buffer pH = 10, I = 0.0318 and 300 K by equilibrium dialysis and temperature scanning spectrophotometry techniques and method for calculation of average hydrophobicity. The binding data has been analyzed, in terms of binding capacity concept $({\theta})$, Hill coefficient (nH) and intrinsic Gibbs free energy of binding $({\Delta}Gbv).$ The results of binding data, melting point (Tm) and average hydrophobicity show that human hemoglobin has more structural stability than bovine hemoglobin sample. Moreover the results of binding data analysis represent the systems with two and one sets of binding sites for hemoglobin and globin, respectively. It seems that the destabilization of hemoglobin structure due to removal of heme group, is responsible of such behavior. The results indicating the removal of heme group from hemoglobin caused the depletion of first binding set as an electrostatic site upon interaction with DTAB and exposing the hydrophobic patches for protein.