- In situ IRRAS studies of molecular recognition of barbituric acid lipids to melamine at the air-water interface
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Recognition and detection of melamine are of very significance in food industries. Molecular recognitions of barbituric acid lipids to melamine at the air-water interface have been investigated in detail using in situ infrared reflection absorption spectroscopy (IRRAS). Hydrogen bonding patterns and molecular orientations of the molecular recognitions have been revealed. Prior to molecular recognition, the barbituric acid moieties in the monolayers were hydrogen bonded with a flat-on fashion at the air-water interface, and the alkyl chains were preferentially oriented with their CCC planes perpendicular to the water surface. After molecular recognition, the NH2 stretching bands of recognized melamine were clearly observed at the air-water interface as well as primary characteristic bands, the barbituric acid moieties underwent a change in orientation with non-hydrogen bonded C4=O bonds almost perpendicular to the water surface and C2=O and C6=O bonds involved in hydrogen bonds with melamine, and the alkyl chains were preferentially oriented with their CCC planes parallel to the water surface. The monolayers of barbituric acid lipids exhibited excellent selectivity for melamine over nucleosides.
- Kong, Xianming,Du, Xuezhong
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- Hydrogen bonding network formed between accumulated Langmuir-Blodgett films of barbituric acid and triaminotriazine derivatives
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Accumulated Langmuir-Blodgett (LB) films that consist of two layers of barbituric acid (BA) and triaminotriazine (TAZ) derivatives (C18BA and 2C18TAZ) were deposited at various surface pressures on a gold-evaporated glass slide covered with a deuterated cadmium stearate (CdSt-d35) monolayer. The two-monolayer LB films (the CdSt-d35 layer is considered to be a part of the substrate) were measured by infrared reflection-absorption (IRRA) spectrometry to investigate the hydrogen-bonding network formed between the two layers. The most notable results were given by the LB film that has the layer configuration of IR// C18BA/2C18TAZ/CdSt-d35/Au. The C18BA layer was deposited at various surface pressures on the 2C18TAZ monolayer. Depending on the surface pressure, the wavenumber of the C=O stretching vibration band (v-(C=O)), derived from BA, showed drastic change. At 20 mN m-1, the C=O groups were found to be in non-hydrogen bonded state (1755 cm-1) to a large extent. The non-hydrogen bonded C=O groups are, in general, rarely seen for the interacted BA/TAZ system. The extraordinary non-hydrogen bonded C=O groups were explained readily by a novel schematic model that was estimated through the molecular orientational analysis. In consequent, the film-to-film interaction is found to give a quite unique hydrogen bonding network structure.
- Hasegawa, Takeshi,Hatada, Yuko,Nishijo, Jujiro,Umemura, Junzo,Huo, Qun,Leblanc, Roger M.
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- NOVEL XYLENE-BASED AMPHIPHILIC COMPOUND AND USE THEREOF
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The present invention relates to a xylene-based amphiphilic compound, a method for preparing the same, and a method for extracting, solubilizing, stabilizing or crystallizing a membrane protein using the same. By using the xylene-based compound according to the present invention, a membrane protein may be stably stored in an aqueous solution for a long time, and may be applied in functional and structural analyses. The structural and functional analysis of the membrane protein is one of the fields of highest interest in biology and chemistry, and the xylene-based compound according to the present invention can be applied in research on protein structure that is closely related to development of a new drug.
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Paragraph 0178; 0179; 0216; 0236; 0261
(2018/10/19)
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- Solution parallel synthesis of cyclic guanidines
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An efficient method for the solution phase synthesis of cyclic guanidines is presented. A variety of 2-substituted monoprotected propanediamines react with a set of 5-substituted 2-methylthio-3,4,5,6- tetrahydropyrimidines under Rathke conditions for the construction of a potential library of 81 cyclic guanidines.
- Marmillon, Christelle,Bompart, Jacques,Calas, Michèle,Escale, Roger,Bonnet, Pierre-Antoine
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p. 1317 - 1328
(2007/10/03)
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- Design and synthesis of sodium ion-selective ionophores based on 16-crown-5 derivatives for an ion-selective electrode
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To develop an ionophore that is highly selective for sodium for use in an ion-selective electrode, we propose a model based on 16-crown-5 which has a cavity just the size of Na+ and has a "block" subunit to prevent complex formation with ions l
- Suzuki, Koji,Sato, Kazunari,Hisamoto, Hideaki,Siswanta, Dwi,Hayashi, Kazuo,Kasahara, Noriko,Watanabe, Kazuhiko,Yamamoto, Noriko,Sasakura, Hideshi
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p. 208 - 215
(2007/10/03)
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- O-acyl-alkanediol-phospholipids and processes for the treatment of asthma
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The invention relates to new O-acyl-alkanediol-phospholipids of the general formula I STR1 processes for their preparation and process for the treatment of certain diseases in humans.
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- Lipophilic Complexones, Part 3. Synthesis of Polyamines Derived from 2-Alkyl-1,3-propanediols and 2,2-Bis(hydroxymethyl)alkanols
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Lipophilic di-, tri-, tetra-, and hexaamines were synthesized from 2-alkyl-1,3-propanediols and 2,2-bis(hydroxymethyl)alkanols.The alcohols were converted into the sulfonate esters which were substituted with ethylenediamine or sodium azide.The azides were directly reduced to give amines.Also dioxyethylenated 2-octadecyl-1,3-propanediol yielded the corresponding amine.Some amines were converted into the salicylidene derivatives. - Keywords: Complexone; Polyamines
- Skarzewski, Jacek,Daniluk, Ewa
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p. 1071 - 1078
(2007/10/02)
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