The Experts below are selected from a list of 651540 Experts worldwide ranked by ideXlab platform
Joachim H. Von Elbe - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Solutes on Zinc Complex Formation in Heated Green Vegetables
Journal of Agricultural and Food Chemistry, 1994Co-Authors: Luke F. Laborde, Joachim H. Von ElbeAbstract:The effect of solutes on the Formation of zinc Complexes of chlorophyll derivatives in processed green vegetables was studied using a pea puree model system containing added Zn 2+ and heated at 121 o C for 30 min. Divalent cations decreased the pH of unheated purees and zinc Complex Formation after heating, suggesting that the pH-lowering effect of divalent cations may influence Complex Formation during heating. Malate, tartrate, citrate, phosphate, and EDTA anions decreased zinc Complex Formation because of their ability to chelate Zn 2+ . Thiocyanate, benzoate, oleate, and caprylate anions increased Complex Formation, while sucrose, glucose, and fructose had no effect on the reaction
Kentaro Yamaguchi - One of the best experts on this subject based on the ideXlab platform.
-
Equimolar Complex Formation of Urea or Thiourea with 2-alkoxy-benzamides: Structural Factors Required for the Equimolar Complex Formation
Journal of inclusion phenomena and macrocyclic chemistry, 2006Co-Authors: Kunikazu Moribe, Kentaro Yamaguchi, Masami Tsuchiya, Yuichi Tozuka, Toshio Oguchi, Keiji YamamotoAbstract:Equimolar Complex Formation of either urea or thiourea with 2-ethoxy-benzamide (2-EB) and 2-methoxy-benzamide (2-MB) was investigated. Complex Formation of urea and 2-MB was observed both by co-grinding method and by coprecipitation method. Molecular arrangement of the Complex was determined by single crystal X-ray diffraction method as an equimolar Complex. The crystal structure of the urea-2-MB Complex, especially hydrogen bond networks, was quite different from that of thiourea-2-MB Complex. In urea-2-MB equimolar Complex, not only intermolecular hydrogen bond between urea and 2-MB but also hydrogen bond network between urea molecules played important roles to form the Complex. When urea was co-ground with 2-EB, equimolar Complex Formation was not observed. ConFormational change of guest molecules by the Complexation was investigated in terms of intramolecular hydrogen bond length and the dihedral angles. Reduction of intramolecular hydrogen bond length of 2-MB and the conFormational change to the flatter structure affected the equimolar Complex Formation.
-
Grinding-induced equimolar Complex Formation between thiourea and ethenzamide.
Chemical & pharmaceutical bulletin, 2004Co-Authors: Kunikazu Moribe, Kentaro Yamaguchi, Masami Tsuchiya, Yuichi Tozuka, Toshio Oguchi, Keiji YamamotoAbstract:We prepared and characterized a grinding-induced equimolar Complex of thiourea with ethenzamide. When thiourea and ethenzamide were co-ground at a molar ratio of 3 : 1, new powder X-ray diffraction (PXRD) peaks were observed in addition to PXRD peaks of thiourea crystals. The optimum stoichiometry of the new structure was confirmed as 1 : 1 mol/mol. Effect of grinding time on the thiourea-ethenzamide equimolar Complex Formation was investigated by using PXRD, differential scanning calorimetry and Fourier transform infrared spectroscopy. The equimolar crystal structure was confirmed by X-ray diffraction measurements of the single crystal which was recrystallized from ethanol. It was found that the intermolecular hydrogen bond Formations between thiourea and ethenzamide molecules contributed to the equimolar Complex Formation. The Complex Formation was not observed in the cases where benzamide, salicylamide or 3-ethoxybenzamide was co-ground with thiourea. 2-Alcoxyl benzamide structures should be required for the grinding-induced equimolar Complex Formation with thiourea.
-
unprecedented host induced intramolecular charge transfer Complex Formation
Chemical Communications, 2002Co-Authors: Soowhan Choi, Shigeru Sakamoto, Young Ho Ko, Kentaro YamaguchiAbstract:For the first time, host-induced intramolecular charge-transfer Complex Formation in a guest containing both an electron donor and an electron acceptor is demonstrated in the cucurbit[8]uril cavity, leading to unusual back-folding of the guest molecule.
Herbert Dautzenberg - One of the best experts on this subject based on the ideXlab platform.
-
polyelectrolyte Complex Formation in highly aggregating systems 1 effect of salt polyelectrolyte Complex Formation in the presence of nacl
Macromolecules, 1997Co-Authors: Herbert DautzenbergAbstract:Polyelectrolyte Complex Formation between components with strong ionic groups and high molecular weights were studied by static light scattering as a function of the mixing ratio and the ionic strength of the medium. Sodium poly(styrenesulfonate) and sodium poly(methacrylate) were used as polyanions and poly(diallyldimethylammonium chloride) and its copolymer with acrylamide were used as polycations. Very small amounts of sodium chloride lead to a drastic decrease of the level of aggregation, while higher ionic strength results in macroscopic flocculation.
Luke F. Laborde - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Solutes on Zinc Complex Formation in Heated Green Vegetables
Journal of Agricultural and Food Chemistry, 1994Co-Authors: Luke F. Laborde, Joachim H. Von ElbeAbstract:The effect of solutes on the Formation of zinc Complexes of chlorophyll derivatives in processed green vegetables was studied using a pea puree model system containing added Zn 2+ and heated at 121 o C for 30 min. Divalent cations decreased the pH of unheated purees and zinc Complex Formation after heating, suggesting that the pH-lowering effect of divalent cations may influence Complex Formation during heating. Malate, tartrate, citrate, phosphate, and EDTA anions decreased zinc Complex Formation because of their ability to chelate Zn 2+ . Thiocyanate, benzoate, oleate, and caprylate anions increased Complex Formation, while sucrose, glucose, and fructose had no effect on the reaction
Annette E. Fleckenstein - One of the best experts on this subject based on the ideXlab platform.
-
Mechanisms underlying methamphetamine-induced dopamine transporter Complex Formation
The Journal of pharmacology and experimental therapeutics, 2009Co-Authors: Gregory C. Hadlock, Anthony J. Baucum, Jill L. King, Kristen A. Horner, Glen A. Cook, James W. Gibb, Diana G. Wilkins, Glen R. Hanson, Annette E. FleckensteinAbstract:Repeated, high-dose methamphetamine (METH) administrations cause persistent dopaminergic deficits in rodents, nonhuman primates, and humans. In rats, this treatment also causes the Formation of high-molecular mass (greater than approximately 120 kDa) dopamine transporter (DAT)-associated Complexes, the loss of DAT monomer immunoreactivity, and a decrease in DAT function, as assessed in striatal synaptosomes prepared 24 h after METH treatment. The present study extends these findings by demonstrating the regional selectivity of DAT Complex Formation and monomer loss because these changes in DAT immunoreactivity were not observed in the nucleus accumbens. Furthermore, DAT Complex Formation was not a consequence limited to METH treatment because it was also caused by intrastriatal administration of 6-hydroxydopamine. Pretreatment with the D2 receptor antagonist, eticlopride [S-(-)-3-chloro-5-ethyl-N-[(1-ethyl-2-pyrrolidinyl)methyl]-6-hydroxy-2-methoxybenzamide hydrochloride], but not the D1 receptor antagonist, SCH23390 [R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrochloride], attenuated METH-induced DAT Complex Formation. Eticlopride pretreatment also attenuated METH-induced DAT monomer loss and decreases in DAT function; however, the attenuation was much less pronounced than the effect on DAT Complex Formation. Finally, results also revealed a negative correlation between METH-induced DAT Complex Formation and DAT activity. Taken together, these data further elucidate the underlying mechanisms and the functional consequences of repeated administrations of METH on the DAT protein. Furthermore, these data suggest a multifaceted role for D2 receptors in mediating METH-induced alterations of the DAT and its function.