• Title/Summary/Keyword: Inter-and Intra-Molecular Interactions

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The Influence of Dielectric Constant on Ionic and Non-polar Interactions

  • Hwang, Kae-Jung;Nam, Ky-Youb;Kim, Jung-Sup;Cho, Kwang-Hwi;Kong, Seong-Gon;No, Kyoung-Tai
    • Bulletin of the Korean Chemical Society
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    • v.24 no.1
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    • pp.55-59
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    • 2003
  • This work is focused on analyzing ion-pair interactions and showing the effect of solvent induced inter-atomic attractions in various dielectric environments. To estimate the stability of ion-pairs, SCI-PCM ab initio MO calculations were carried out. We show that the solvent-induced attraction or ‘cavitation' energy of the ion-pair interactions in solution that arises mainly from the stabilization of the water molecules by the generation of an electrostatic field. In fact, even the strong electrostatic interaction characteristic of ion-pair interactions in the gas phase cannot overcome the destabilization or reorganization of the water molecules around solute cavities that arise from cancellation of the electrostatic field. The solvent environment, possibly supplemented by some specific solvent molecules, may help place the solute molecule in a cavity whose surroundings are characterized by an infinite polarizable dielectric medium. This behavior suggests that hydrophobic residues at a protein surface could easily contact the side chains of other nearby residues through the solvent environment, instead of by direct intra-molecular interactions.

Single Interaction Force of Biomolecules Measured with Picoforce AFM (원자 힘 현미경을 이용한 단일 생분자 힘 측정)

  • Jung, Yu-Jin;Park, Joon-Won
    • Journal of the Korean Vacuum Society
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    • v.16 no.1
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    • pp.52-57
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    • 2007
  • The interaction force between biomolecules(DNA-DNA, antigen-antibody, ligand-receptor, protein-protein) defines not only biomolecular function, but also their mechanical properties and hence bio-sensor. Atomic force microscopy(AFM) is nowadays frequently applied to determine interaction forces between biological molecules and biomolecular force measurements, obtained for example using AFM can provide valuable molecular-level information on the interactions between biomolecules. A proper modification of an AFM tip and/or a substrate with biomolecules permits the direct measurement of intermolecular interactions, such as DNA-DNA, protein-protein, and ligand-receptor, etc. and a microcantilever-based sensor appeared as a promising approach for ultra sensitive detection of biomolecular interactions.

Fluorescence Behavior Associated with a Possible Intercolumnar Charge-transfer Interaction in the Crystalline State of a Dyad Consisting of Mesitylene and 1,4-Dicyano-2-methylnaphthalene Subunits

  • Ohta, Eisuke;Kobayashi, Hitoshi;Sakai, Atsushi;Matsui, Yasunori;Sato, Hiroyasu;Ikeda, Hiroshi
    • Rapid Communication in Photoscience
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    • v.4 no.2
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    • pp.31-33
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    • 2015
  • Fluorescence (FL) properties of a novel donor-acceptor dyad, comprised of mesitylene and 1,4-dicyano-2-methylnaphthalene (DCMN) subunits connected by an ether linkage, were elucidated. The dyad in cyclohexane exhibits FL arising from an intramolecular exciplex. In the crystalline state, the dyad does not emit light from intra- and inter-molecular exciplexes but rather displays FL that is nearly equivalent to that of 2-methoxymethyl-substituted DCMN. However, the emission spectrum of the crystalline dyad contains a shoulder in the long wavelength region, suggesting that weak intercolumnar charge-transfer interactions take place between columns consisting of the mesitylene and DCMN subunits.

Crystal and Molecular Structure of Methyl 12-(3-bromophenyl)-9-[(4-methylbenzene)sulfonyl]-22-oxo-13,21-dioxa-9-azapentacyclo[12.8.0.02,11.03,8.015,20]docosa-1(14),3,5,7,15(20),16,18-heptaene-11-carboxylate

  • Kothandan, Gugan;Ganapathy, Jagadeesan;Damodharan, Kannan;Sanmargam, Aravindhan
    • Journal of Integrative Natural Science
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    • v.7 no.2
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    • pp.92-102
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    • 2014
  • The crystal structure of the title compounds with both coumarin and sulfonamide moieties were examined. These two groups have very special for their pharmaceutical and medicinal properties have been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group C2/c with unit cell dimension a = 28.633(3) ${\AA}$, b= 9.3215(7) ${\AA}$ and c= 24.590(2) ${\AA}$ [alpha & gamma=$90^{\circ}$ beta= $115.976(3)^{\circ}$]. In the structure The S1 atom shows a distorted tetrahedral geometry, with O1-S1-O2 [119.74 $(2)^{\circ}$] and N1-S1-C5 [$105.57(1)^{\circ}$] angles deviating from ideal tetrahedral values are attributed to the Thrope-Ingold effect. The sum of bond angles around N1 ($316.2(1)^{\circ}$) indicates that N1 is in sp2 hybridization. The Pyridine ring adopts boat conformation and pyran rings adopt a sofa conformation. The carboxylate group of atoms were disordered over two positions with site occupancy factors 0.598 (9):0.402 (9). Crystal structure and packing is stabilized by $C-H{\ldots}O$ intra and inter molecular hydrogen bond interactions.

Aromatic Agriculture: Volatile Compound-Based Plant Disease Diagnosis and Crop Protection (향기농업: 휘발성 물질을 이용한 식물병 진단과 방제)

  • Riu, Myoungjoo;Son, Jin-Soo;Oh, Sang-Keun;Ryu, Choong-Min
    • Research in Plant Disease
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    • v.28 no.1
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    • pp.1-18
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    • 2022
  • Volatiles exist ubiquitously in nature. Volatile compounds produced by plants and microorganisms confer inter-kingdom and intra-kingdom communications. Autoinducer signaling molecules from contact-based chemical communication, such as bacterial quorum sensing, are relayed through short distances. By contrast, biogenic volatiles derived from plant-microbe interactions generate long-distance (>20 cm) alarm signals for sensing harmful microorganisms. In this review, we discuss prior work on volatile compound-mediated diagnosis of plant diseases, and the use of volatile packaging and dispensing approaches for the biological control of fungi, bacteria, and viruses. In this regard, recent developments on technologies to analyze and detect microbial volatile compounds are introduced. Furthermore, we survey the chemical encapsulation, slow-release, and bio-nano techniques for volatile formulation and delivery that are expected to overcome limitations in the application of biogenic volatiles to modern agriculture. Collectively, technological advances in volatile compound detection, packaging, and delivery provide great potential for the implementation of ecologically-sound plant disease management strategies. We hope that this review will help farmers and young scientists understand the nature of microbial volatile compounds, and shift paradigms on disease diagnosis and management to aromatic (volatile-based) agriculture.