Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.2.42 (DTA)
 1,693 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A series of new vitamin B6 triethanolamine rare earth (III) complexes Re(PN)3(TEA)(NO3)2Cl (PN = pyridoxol; TEA = triethanolamine; Re = La1, Ce2, Pr3, Nd4, Sm5, Tb6, Dy7, Ho8, Er9, Y10), were synthesized and characterized by elemental analysis, molar conductance, TGA-DTA, UV, IR, and 1H NMR spectroscopic techniques. The suppression ratio of complexes for the hydroxyl radical (OH.) and the superoxide radical (O2-.) were determined, the results show that these complexes possess scavenging effects on OH. and O2(-.). In this paper we also discuss the effect of complex conc. for the suppression ratio on superoxide radical O2(-.).
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PMID:Synthesis, characterization, and antioxidative activity of new vitamin B6 triethanolamine rare earth (III) complexes. 825 35

Glass-ceramic powders with the oxide batch formulation 50wt%SiO2, 20wt%P2O5 and 30wt%CaO were prepared by the sol-gel process using tetraethoxysilane, calcium nitrate and phosphoric acid as raw materials. The obtained gels and powders were characterized by TG-DTA thermal analysis, FTIR analyses and XRD measurements. The results indicated that (1) heating to more than 600 degrees C brought about elimination of -OC2H5 side chains from gels, and formation of a SiO2-based glass network, (2) crystallization such as Ca3(PO4)2 notably occurred in the SiO2-based glass matrix when heated to more than 900 degrees C, (3) -OH groups existed on SiO2-based glass-ceramic surfaces in the temperature region less than 900 degrees C, and (4) the melting point of this composition was more than 1400 degrees C. This study suggests that sol-gel-derived SiO2-based glass-ceramic powder containing P and Ca might be useful as bioactive implant materials.
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PMID:Characterization of 50wt%SiO2-20wt%P2O5-30wt%CaO glass-ceramic powders prepared by the sol-gel process. 955 50

Three kinds of amorphous aluminosilicates were synthesized by coprecipitation of silicic acid with aluminum hydroxide in the presence of different inorganic ions: sulfate, chloride, and nitrate. Although the bulk composition of the aluminosilicates obtained was not affected by anion species, their DTA spectra were significantly different, suggesting that their structures also differ. The local structure of Al and Si in the aluminosilicates was studied in detail by 27Al and 29Si MAS NMR. From the 27Al MAS NMR spectra and comparison between 29Si HD- and CP-MAS NMR spectra, it was concluded that the aluminosilicate obtained in the presence of sulfate ions has only a montmorillonite-like structure, whereas in the cases of chloride and nitrate, the solids are composed of three phases: aluminum hydroxide, silica, and the montmorillonite-like aluminosilicate. The difference in the local structure of Al and Si in the aluminosilicates was explained by the difference in interaction between the anions and aluminum ions. Copyright 1999 Academic Press.
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PMID:Effects of Anions on Local Structure of Al and Si in Aluminosilicates. 1033 80

To investigate the relationship between antimicrobial activities and the molecular structures of nickel(II) complexes with thiosemicarbazone and semicarbazone ligands, nickel(II) complexes with ligands Hmtsc, Hatsc, Hasc and H2dmtsc, were prepared and characterized by elemental analysis, FT-IR, 1H and 13C NMR spectroscopies, magnetic susceptibility measurements, UV-Vis absorption spectra, TG/DTA and single-crystal X-ray analysis. Their antimicrobial activities were evaluated by the MIC against four bacteria (B. subtilis, S. aureus, E. coli and P. aeruginosa), two yeasts (C. albicans and S. cerevisiae) and two molds (A. niger and P. citrinum). The 4-coordinate, diamagnetic nickel(II) complexes showed antimicrobial activities which were different from those of free ligands or the starting nickel(II) compounds; [Ni(mtsc)(OAc)] 1 showed selective and effective antimicrobial activities against two Gram-positive bacteria (B. subtilis and S. aureus) and modest activities against a yeast (S. cerevisiae), [Ni(mtsc)Cl] 3 exhibited moderate activities against a Gram-positive bacterium (S. aureus), and [Ni(atsc)(OAc)] 5 showed modest activities against two Gram-positive bacteria (B. subtilis and S. aureus). On the other hand, the 6-coordinate, paramagnetic nickel(II) complexes with two protonated or deprotonated ligands ([Ni(mtsc)2] 2, [Ni(atsc)(mtsc)] 4, [Ni(atsc)2] 6, [Ni(Hatsc)2](NO3)(2)7, [Ni(Hatsc)2]Cl(2)8 and [Ni(Hasc)2](OAc)(2)9) and the sterically crowded 4-coordinate, diamagnetic nickel(II) complex ([Ni(dmtsc)] 10) did not inhibit the growth of the test organisms. The structure-activity correlation in this series of nickel(II) complexes was discussed based on their ligand-replacement abilities.
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PMID:Synthesis, structural characterization and antimicrobial activities of 4- and 6-coordinate nickel(II) complexes with three thiosemicarbazones and semicarbazone ligands. 1133 Apr 82

Trichloroethylene (TCE) decomposition over a MnOx/ gamma-Al2O3 catalyst in a fixed-bed reactor was conducted in this study. The MnOx/gamma-Al2O3 powders were prepared by the incipient wetness impregnation method with aqueous solution of manganese nitrate. The catalysts were characterized by DTA-TGA, XRD, porosity analysis, SEM, EDX, and XPS. The results show that the main distinct weight loss is found at the temperature around 373 and 873 K,the MnO peaks (2theta = 34.9 degrees and 40.5 degrees) are only observed crystal phase on the fresh catalyst, the SEM image of the MnOx-impregnated gamma-Al2O3 support is much different from the calcined catalyst, and the Mn element quantity on the catalyst surface is higher than that of the impregnated support. The products and reactants distributions from the oxidation of TCE over MnOx/gamma-Al2O3 were analyzed by GC. The results show that the TCE conversion starts from 5% at 443 K and rises to very high values in the 673-873 K ranges and that the CO2 yield also pushes to 99% at the same temperature ranges. HCl and Cl2 are the other main products with little halogenated VOC intermediates.
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PMID:Characterization of gamma-alumina-supported manganese oxide as an incineration catalyst for trichloroethylene. 1254 7

Novel bismuth(III) complexes 1-4 with the tridentate thiosemicarbazone ligand of 2N1S donor atoms [Hmtsc (L1); 2-acetylpyridine (4N-morpholyl thiosemicarbazone)], the pentadentate double-armed thiosemicarbazone ligand of 3N2S donor atoms [H2dmtsc (L3); 2,6-diacetylpyridine bis(4N-morpholyl thiosemicarbazone)] and the pentadentate double-armed semicarbazone ligand of 3N2O donor atoms [H2dasc (L4b); 2,6-diacetylpyridine bis(semicarbazone)], were prepared by reactions of bismuth(III) nitrate or bismuth(III) chloride and characterized by elemental analysis, thermogravimetric and differential thermal analysis (TG/DTA), FTIR and NMR (1H and 13C) spectroscopy. The crystal and molecular structures of complexes 1, 2a, 2b and 4b, and the "free" ligand L1 were determined by single-crystal X-ray structure analysis. The dimeric 7-coordinate bismuth(III) complex [Bi(dmtsc)(NO3)]2, 1, and the monomeric 7-coordinate complexes [Bi(Hdasc)(H2O)](NO3)2.H2O (major product), 2a, and [Bi(dasc)(H2O)]NO3.H2O (minor product), 2b, all with pentagonal bipyramidal bismuth(III) centers, are depicted with one electron pair (6s2) of the bismuth(III) atom, deprotonated forms of multidentate thiosemicarbazone or semicarbazone ligands, and monodentate NO3 or H2O ligands, respectively. These complexes are related to the positional isomers of one electron pair of the bismuth(III) atom; 1 has an electron pair positioned in the pentagonal plane (basal position), while 2a and 2b have an electron pair in the apical position. The monomeric 8-coordinate complex [Bi(mtsc)2(NO3)], 4b, which was obtained by slow evaporation in MeOH of the 1.5 hydrates 4a, was depicted with one electron pair of the bismuth(III) atom, two deprotonated mtsc- ligand and one nitrate ion. On the other hand, crystals of the complex "[Bi(mtsc)Cl2]", 3, prepared by a reaction of BiCl3 with L1 showed several polymorphs (3a, 3b, 3c and 3d) due to coordination and/or solvation of dimethyl sulfoxide (DMSO) used in the crystallization. Bismuth(III) complexes 1 and 4a showed selective and effective antibacterial activities against Gram-positive bacteria. The structure-activity relationship was discussed.
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PMID:Syntheses, crystal structures and antimicrobial activities of monomeric 8-coordinate, and dimeric and monomeric 7-coordinate bismuth(III) complexes with tridentate and pentadentate thiosemicarbazones and pentadentate semicarbazone ligands. 1504 Dec 40

A complex of cerium(III) with 4-methyl-7-hydroxycoumarin was synthesized by mixing water solutions of cerium(III) nitrate and 4-methyl-7-hydroxycoumarin sodium salt in a metal-to-ligand molar ratio of 1:2. The complex was characterized and identified by elemental analysis, conductometry, IR, 1H and 13C NMR-spectroscopy, mass spectral data, DTA and TGA. Thermal analysis of the complex indicated the formation of a compound of the composition CeR2(OH).5H2O, R standing for the ligand. The reaction of cerium(III) with 4-methyl-7-hydroxycoumarin was studied in detail by the spectrophotometric method. The stepwise formation of two complexes, vis., CeR2+ and CeR2+, was established in the pH region studied. The equilibrium constants for 1:1 and 1:2 complexes were determined to be 10.72 and 9.22, respectively.
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PMID:Stability of the complexes of some lanthanides with coumarin derivatives. I. Cerium(III)-4-methyl-7-hydroxycoumarin. 1505 43

A complex of neodymium(III) with 4-hydroxy-3[1-(4-nitrophenyl)-3-oxobutyl]-2H-1-benzopyran-2-one (acenocoumarol) was synthesized by mixing water solutions of neodymium(III) nitrate and the ligand (metal to ligand molar ratio of 1:3). The complex was characterized and identified by elemental analysis, conductivity, IR, 1H NMR and mass spectral data. DTA and TGA were applied to study the composition of the compound. Elemental and mass spectral analysis of the complex indicated the formation of a compound of the composition NdR3 x 6H2O, where R = C19H14NO6-) The reaction of neodymium(III) with acenocoumarol was studied in detail by the spectrophotometric method. The stepwise formation of three complexes, vis., NdR2+, NdR2+ and NdR3 was established in the pH region studied (pH 3.0-7.5). The equilibrium constants for 1:1, 1:2 and 1:3 complexes were determined to be log K1 = 6.20 +/- 0.06; log K2 = 3.46 +/- 0.07 and log K2) = 2.58 +/- 0.05, respectively.
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PMID:Stability of the complexes of some lanthanides with coumarin derivatives. II. Neodymium(III)-acenocoumarol. 1527 55

Mercuric-5-nitrotetrazole (MNT) was synthesized on using a reported method. The product having bulk density of 1.5 g/cm3, was obtained during this work using mercuric nitrate doped with additives such as cephol/dextrin in the process. Synthesized MNT was characterized by metal content analysis, IR and ESCA. The DTA profile indicated the thermal stability of MNT up to 200 degrees C. It revealed its higher thermally sensitive [thermal sensitive figure (S) approximately 0.8] in comparison to that of service lead azide (SLA) [S approximately 0.4]. Percussion sensitivity data also showed higher sensitivity of MNT. However, it was found less friction sensitive than SLA. The chemical stability of MNT in a carbon dioxide environment was evaluated in comparison to SLA by determining mercury (gravimetrically) and lead azide (volumetrically) contents respectively. Results obtained indicated that no discernable changes occurred in MNT, even after storage for 90 days while in case of SLA, drastic change in lead azide content was observed. IR spectra of MNT sample stored in a closed aluminum dish for 5-10 years could be superimposed on that of the freshly prepared MNT sample. The performance of MNT filled detonator no. 27 assessed in terms of extent of damage on a witness plate was found equivalent to that of the standard ASA (azide, styphynate and aluminium) composition filled detonator.
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PMID:Synthesis, characterization, thermolysis and performance evaluation of mercuric-5-nitrotetrazole (MNT). 1536 11

Nano-crystalline Co3O4 and CoO powders have been prepared by a spray pyrolysis approach. The effects of the reaction temperature and initial salts on the crystallinity and phase composition have been studied. Based on the TEM and XRD results, the crystal sizes were in the range of 1-10 nm. SEM and TEM observations also reveal that the nano-powders easily create micron-scale spherical agglomerates. The Co3O4 powders obtained by spraying nitrate solution at 500 degrees C show high specific surface area, which according to the BET method is 82.37 m2/g. The time/temperature phase diagram of cobalt oxides developed from XRD and DTA/TGA analyses shows the existence of a CoO phase at low and high temperature ranges when some specific preparation conditions are applied.
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PMID:In-situ fabrication of nanostructured cobalt oxide powders by spray pyrolysis technique. 1557 Sep 73


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