• Title/Summary/Keyword: Molecular structures

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Pharmacophore Identification for Peroxisome Proliferator-Activated Receptor Gamma Agonists

  • Sohn, Young-Sik;Lee, Yu-No;Park, Chan-In;Hwang, S-Wan;Kim, Song-Mi;Baek, A-Young;Son, Min-Ky;Suh, Jung-Keun;Kim, Hyong-Ha;Lee, Keun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.32 no.1
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    • pp.201-207
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    • 2011
  • Peroxisome proliferator-activated receptors (PPARs) are members of nuclear receptors and their activation induces regulation of fatty acid storage and glucose metabolism. Therefore, the $PPAR\gamma$ is a major target for the treatment of type 2 diabetes mellitus. In order to generate pharmacophore model, 1080 known agonists database was constructed and a training set was selected. The Hypo7, selected from 10 hypotheses, contains four features: three hydrogen-bond acceptors (HBA) and one general hydrophobic (HY). This pharmacophore model was validated by using 862 test set compounds with a correlation coefficient of 0.903 between actual and estimated activity. Secondly, CatScramble method was used to verify the model. Hence, the validated Hypo7 was utilized for searching new lead compounds over 238,819 and 54,620 chemical structures in NCI and Maybridge database, respectively. Then the leads were selected by screening based on the pharmacophore model, predictive activity, and Lipinski's rules. Candidates were obtained and subsequently the binding affinities to $PPAR\gamma$ were investigated by the molecular docking simulations. Finally the best two compounds were presented and would be useful to treat type 2 diabetes.

Flavonoids and Aromatic Compounds from the Rhizomes of Zingiber zerumbet

  • Jang Dae Sik;Han Ah-Reum;Park Gowooni;Jhon Gil-Ja;Seon Eun-Kyoung
    • Archives of Pharmacal Research
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    • v.27 no.4
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    • pp.386-389
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    • 2004
  • Repeated column chromatography of the CHCI_3-soluble fraction of Zingiber zerumbet led to the isolation and identification of two aromatic compounds, p-hydroxybenzaldehyde (1) and vanillin (2), and six kaempferol derivatives, kaempferol-3,4',7-O-trimethylether (3), kaempferol-3-O-methylether (4), kaempferol-3,4'-O-dimethylether (5), 4'-O-acetylafzel in (6), kaempferol-3-O-(4-O-acetyl-$\alpha$-L-rhamnopyranoside)], 2',4'-O-diacetylafzelin (7), kaempferol-3-O-(2,4-O-diacetyl-$\alpha$-L-rhamnopyranoside)], and 3',4'-O-diacetylafzelin (8), kaempferol-3-O-(3,4-O-diacetyl-$\alpha$-L-rhamnopyranoside)]. The structures of 1-8 were identifed by analysis of spectroscopic data as well as by comparison with published values. This is the first report on the isolation of compounds 1-3 from this plant.

Nanotechnology Applications in Functional Foods; Opportunities and Challenges

  • Singh, Harjinder
    • Preventive Nutrition and Food Science
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    • v.21 no.1
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    • pp.1-8
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    • 2016
  • Increasing knowledge on the link between diet and human health has generated a lot of interest in the development of functional foods. However, several challenges, including discovering of beneficial compounds, establishing optimal intake levels, and developing adequate food delivering matrix and product formulations, need to be addressed. A number of new processes and materials derived from nanotechnology have the potential to provide new solutions in many of these fronts. Nanotechnology is concerned with the manipulation of materials at the atomic and molecular scales to create structures that are less than 100 nm in size in one dimension. By carefully choosing the molecular components, it seems possible to design particles with different surface properties. Several food-based nanodelivery vehicles, such as protein-polysaccharide coacervates, multiple emulsions, liposomes and cochleates have been developed on a laboratory scale, but there have been very limited applications in real food systems. There are also public concerns about potential negative effects of nanotechnology-based delivery systems on human health. This paper provides an overview of the new opportunities and challenges for nanotechnology-based systems in future functional food development.

Solution Structure of pA2, the Mimotopic Peptide of Apolipoprotein A-I, by NMR Spectroscopy

  • Won, Ho-Shik
    • Bulletin of the Korean Chemical Society
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    • v.32 no.11
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    • pp.4016-4020
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    • 2011
  • A number of mimetic peptides of apolipoprotein A-I, a major component for high density lipoproteins (HDL), were screened from the phase-displayed random peptide library by utilizing monoclonal antibodies (A12). A mimetic peptide for A12 epitope against apolipoprotein A-I was selected as FVLVRDTFPSSVCCP(pA2) exhibiting 45% homology with Apo A-I in the BLAST search. Solution structure determination of this mimotope was made by using 2D-NMR data and NMR-based distance geometry (DG)/molecular dynamic calculations. The resulting DG structures had low penalty value of 0.4-0.6 ${\AA}^2$ and the total RMSD of 0.7-1.7 ${\AA}$. The mimotope pA2 exhibited a characteristic ${\beta}$-turn conformation from Val[2] to Phe[8] near Pro[9] residue.

Study of the Resonance Structures of the Preionizing Spectrum of Molecular Hydrogen by Phase-shifted Multichannel Quantum Defect Theory

  • Lee, Chun-Woo
    • Bulletin of the Korean Chemical Society
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    • v.33 no.3
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    • pp.809-817
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    • 2012
  • The resonance structure of the preionization spectrum of $H_2$ in the region immediately above its ionization threshold, ($^2{\sum}_{g}^{+}$, $\nu^+=0$, $N^+=0$) converging toward its rotationally excited ($\nu^+=0$, $N^+=2$) limit, is complicated due to perturbation by the vibrationally excited levels $7_{p\pi}\;v=1$ and $57_{p\pi}\;v=2$. The spectra of interlopers are separated from the rotationally preionizing Rydberg series to allow analysis of this complex resonance structure. Although only two vibrationally excited levels perturb the rotational preionization spectrum, at least 6 interloper Rydberg series participate in the complex spectrum over most of its energy range and more interloper series participate at a narrow range around $124500cm^{-1}$ in the spectrum. To allow handling of an arbitrary number of interloper series, MATLAB$^{(R)}$'s symbolic operation is used to perform on-the-fly formulation.

Ab Initio Study of the Complexation Behavior of p-tert-Butylcalix[5]arene Derivative toward Alkyl Ammonium Cations

  • Choe, Jong-In;Lee, Sang-Hyun;Oh, Dong-Suk;Chang, Suk-Kyu;Nanbu, Shinkoh
    • Bulletin of the Korean Chemical Society
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    • v.25 no.2
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    • pp.190-194
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    • 2004
  • The structures and complexation energies of penta-O-tert-butyl ester 1 of p-tert-butylcalix[5]arene toward a series of alkyl ammonium guests have been optimized by ab initio HF/6-31G method. The calculated complexation efficiencies of 1 for alkyl ammonium guests have been found to be similar to the values of previously reported debutylated-calix[5]arene 2. Calculation results show that both of the calix[5]aryl derivatives have much better complexation ability toward ammonium cation without alkyl group over other alkyl ammonium guests. The structural characteristics of the calculated complexes are discussed as a function of the nature of the alkyl substituents of the ammonium guests.

Study on the realtionship between phthalic and naphthalenic polyimide structures and the photo-induced molecular orientaion of liquid crystals on polyimides

  • Cho, Ki-Yun;Sung, Shi-Joon;Hah, Hyun-Dae;Park, Jung-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.1167-1168
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    • 2004
  • Polarized ultraviolet irradiation techniques have been developed recently to produce alignment of liquid crystals (LC). Because of the excellent thermal stability and the alignment ablility of polyimides, polyimides has attracted considerable research interest for the photoinduced alignment layer. Hasegawa and Taira confirmed homogeneous alignment of LC by the decompostion of a polyimide induced by lineraly ultra-violet polarized light. It was reported that ultraviolet visible absorption spectra of a polyimide alignment film showed a remarkable change upon irradiation. In this study, we synthesized phthalic polyimide and a naphthalenic polyimide in order to investigate the effect of the polyimide structure. Some difference in terms of the photo-induced molecular orientaion of liquid crystals were observed with the polyimide structure.

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Recent Advances in the Innate Immunity of Invertebrate Animals

  • Iwanaga, Sadaaki;Lee, Bok-Luel
    • BMB Reports
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    • v.38 no.2
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    • pp.128-150
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    • 2005
  • Invertebrate animals, which lack adaptive immune systems, have developed other systems of biological host defense, so called innate immunity, that respond to common antigens on the cell surfaces of potential pathogens. During the past two decades, the molecular structures and functions of various defense components that participated in innate immune systems have been established in Arthropoda, such as, insects, the horseshoe crab, freshwater crayfish, and the protochordata ascidian. These defense molecules include phenoloxidases, clotting factors, complement factors, lectins, protease inhibitors, antimicrobial peptides, Toll receptors, and other humoral factors found mainly in hemolymph plasma and hemocytes. These components, which together compose the innate immune system, defend invertebrate from invading bacterial, fungal, and viral pathogens. This review describes the present status of our knowledge concerning such defensive molecules in invertebrates.

C-NMR Spectroscopic Study of Alkylbenzenes as Synthetic Lubricant Base Stocks (합성기유로서의 알킨벤젠의 $^{13}$C-NMR분광학적 연구)

  • 최주환;전용진;최웅수;권오관
    • Tribology and Lubricants
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    • v.9 no.2
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    • pp.16-21
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    • 1993
  • Alkylbenzenes used as the synthetic lubricant base stocks were composed of the mixture of the various kinds of aromatic hydrocarbons. Their compositions have affected on the quality of synthetic alkylbenzene lubricants. Therefore, the rapid and accurate methods for the composit ional analysis are important. In this study, the compositions of the alkylbenzenes (Hv. LAB, FHv. LAB, Hv, BAB, DAB[HF], DAB[$AlCl_3$]) as synthetic base stocks have been investigated according to six average structural parameters(Tar, Nal, Asub, $\bar{n}$, nb, $T\alpha$) in the view of the molecular structures by $^{13}C-NMR$ spectroscopy. The experimental results of the oxidation $\varepsilon$ thermal stability tests have been related to the results of the molecular structural analysis.

Structure and apoptotic function of p73

  • Yoon, Mi-Kyung;Ha, Ji-Hyang;Lee, Min-Sung;Chi, Seung-Wook
    • BMB Reports
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    • v.48 no.2
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    • pp.81-90
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    • 2015
  • p73 is a structural and functional homologue of the p53 tumor suppressor protein. Like p53, p73 induces apoptosis and cell cycle arrest and transactivates p53-responsive genes, conferring its tumor suppressive activity. In addition, p73 has unique roles in neuronal development and differentiation. The importance of p73-induced apoptosis lies in its capability to substitute the pro-apoptotic activity of p53 in various human cancer cells in which p53 is mutated or inactive. Despite the great importance of p73-induced apoptosis in cancer therapy, little is known about the molecular basis of p73-induced apoptosis. In this review, we discuss the p73 structures reported to date, detailed structural comparisons between p73 and p53, and current understanding of the transcription-dependent and -independent mechanisms of p73-induced apoptosis.