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Query: UNIPROT:Q9UMR3 (
NMR
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150,598
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
High heat of enzymatic hydrolysis of triphosphoinositide phosphate bonds and of high-energy phosphates is observed using microcalorimetry. Heats of hydrolysis of triphosphoinositide, ADP and ATP sharply increase with increasing pH values from 6.6 to 7.4. Heat of hydrolysis of diphosphoinositide correlates with that of low-energy phosphates, pK4 and pK5 values for triphosphoinositide are found to be 7.4 and 9.3 respectively by means of potentiometric titration deltaGo' values for diphosphoinositide and triphosphoinositide are -3.5 and -7.1 kcal/mole respectively, taking into consideration the correction for heat neutralization-ionization during hydrolysis. Rapid triphosphoinositide hydrolysis takes place in 1% aqueous
pyridine
solution at 100 degrees C. In contrast to diphosphoinositide and monophosphoinositide, infrared spectra of triphosphoinositide have an additional absorption band at 930 cm(-1). 31P
NMR
method has revealed the presence of one diester and two monoester groups in the molecule of triphosphoinositide. The differences described between triphosphoinositide and other compounds with phosphomonoester groups are suggested to be due to electrostatic nonbounded interaction of vicinal diequatorial phosphate groups.
...
PMID:[Properties of the high energy phosphate bonds of triphosphoinositide]. 2 24
The synthesis of 2-[(7-chloro-4-quinolyl)-amino] benzoic acid 3-
pyridine
carboxamide-N-ethyl ester (nicafenine) was carried out by a new method using isatoic anhydride. The IR,
NMR
, MS and UV spectrophotometric studies are described, together with the characteristics of this compound.
...
PMID:Nicafenine, a new analgesic. I. Synthesis and physicochemical properties. 4 70
It is the aim of a series of investigations to test whether or not beta-pentachloro-1-cyclohexene is an intermediate in the biodegradation of alpha-hexachlorocyclohexane. This paper describes attempts to synthesize this intermediate by chemical methods. 1) Pentachlorocyclohexene was synthesized by partial additive chlorination of chlorobenzene. Combined gas chromatography-mass spectrometry revealed that at least five different isomers of pentachlorocyclohexene had been formed. 2) Treatment of alpha-hexachlorocyclohexane with alkaline buffer (pH 8) produced trichlorobenzenes and, in small yield (4%), a pentachlorocyclohexene. This was isolated and identified as the beta-isomer by melting point (71.8 - 72.6 degrees C, uncorr.), IR- and mass spectrum. Dehydrochlorination of beta-pentachlorocyclohexene produced the trichlorobenzene isomers in a pattern which is characteristic of alpha-hexachlorocyclohexane. The position of the chlorine substituents in the beta-pentachlorocyclohexene molecule as judged from
NMR
studies is e-aeee. This confirms that it is the monodehydrochlorination product of alpha-hexachlorocyclohexane. The configurations of gamma- and delta-pentachlorocyclohexene, determined for comparison, are e-eeaa and e-eeee, respectively. The kinetics of dehydrochlorination of both alpha-hexachlorocyclohexane and beta-pentachlorocyclohexene in alkaline acetone/water (3 + 2) was studied by means of conductometry. Both reactions are of second order: kappa alpha-HCH 0.0495 [1 times mol- minus 1 times s- minus 1[; kappa beta-PCH 0.905 [1 times mol- minus 1 times s- minus 1] (3.6 degrees C). 3) Dehydrochlorination of alpha-hexachlorocyclohexane in
pyridine
/xylene (3 + 4) was also studied. An earlier report claiming that gamma-pentachlorocyclohexene (and not the beta isomer) is produced in this medium was confirmed, if the reaction was performed at high temperature (120 - 140 degrees C). Moreover, the ratio of trichlorobenzene isomers formed from alpha-hexachlorocyclohexane shifted to a pattern characteristic of the gamma (or gamma) isomer. However, at temperatures of 90 degrees C or less, beta-pentachlorocyclohexene was the main product. The results strongly suggest that in
pyridine
/xylene, the same isomer is primarily produced from alpha-hexachlorocyclohexane and is isomerized to the gamma, delta and at least two other isomers of pentachlorocyclohexene before further dehydrochlorination ensues. A simple method for the synthesis of beta-pentachlorocyclohexene is presented.
...
PMID:[On the role of pentachlorocyclohexene in the metabolism and action of hexachlorocyclohexane. I. Synthesis of beta-pentachlorocyclohexene and its identification as the monodehydrochlorination product of alpha-hexachlorocyclohexane (author's transl)]. 5 Feb 59
The rate constants were estimated by phosphorus
NMR
spectroscopy for the reactions of alcohols (Tr-dT, 2-cyanoethanol) in
pyridine
with the main types of the reactive phosphorylating intermediates formed by treatment of pdT-Ac, pdTpdT-Ac, Tr-dTpdT-Ac, Tr-dTpdTpdT-Ac with 2, 4, 6-triisopropylbenzene-sulfonyl chloride (TPS): 1) B type derivatives with phosphomono ester (PME) group converted to a phosphoryl pyridinium residue; 2) C type derivatives with PME and phosphodiester (PDE) groups converted to trisubstituted pyrophosphate; 3) D type derivatives with PDE groups converted to tetrasubstituted pyrophosphate. The two latter types are partially present as cyclic intramolecular pyrophosphates Ci and Di. The reactivity of the intermediates decrease in the series B greater than Ci approximately Di greater than C approximately D. The Ci derivative of pdTpdT-Ac when obtained in dimethylformamide was found to be rather stable to hydrolysis and could be separated from the other dinucleotide derivatives by ion-exchange chromatography. The Arrhenius parameters of all steps of the conversion of PME group of pdT-Ac to B derivative and of the reaction of TPS with PDE group of dinucleoside phosphate Tr-dTpdT-Ac were measured.
...
PMID:The reactivity of phosphomono-and phosphodiester groups in oligonucleotides. 20 74
A series of new fluorine-containing 3,5-disubstituted aryl/alkylisoxazoles has been synthesized by the condensation of hydroxylamine with appropriate beta-diketones in the presence of
pyridine
and characterized by IR and 1H
NMR
spectral studies. These isoxazoles have been screened for their antibacterial activity against the gram positive bacteria, Staphylococcus albus, Streptococcus nonhemolyticus and the gram negative bacterium Escherichia coli.
...
PMID:Studies in potential organo-fluorine antibacterial agents. Part 2: Synthesis and antibacterial activity of some new fluorine-containing 3.5-disubstituted isoxazoles. 37 48
Different dianisyl-pyridyl- and dipyridyl-anisyl-methanoles react with sulfuric acid, hydrogen iodide or formic acid. Depending on the position of the methoxy groups,
pyridine
nucleus and acid demethylation or reduction occurs and 10-aryl-pyridol[1,2-alpha]-indole or 9-pyridyl-xanthenole-9, respectively, are formed as main or byproduct. UV-, IR- and 1H-
NMR
-spectra of the pyridonindoles are discussed.
...
PMID:[The effect of acids on dianisyl-pyridyl- and dipyridyl-anisyl-methanoles (author's transl)]. 58 88
The synthesis of virtually all the lanthanide octaethylporphyrin complexes have been achieved by heating appropriate anhydrous lanthanide halide and octaethylporphyrin in imidazole melt at 210 degrees C for two hours. The lighter lanthanide porphyrin complexes are very susceptible to hydrolysis, the middle lanthanide porphyrin complexes are moderately stable, and the heavier lanthanide porphyrin complexes are relatively more stable to hydrolysis. Two out of four lanthanide porphyrin complexes studied in detail, namely ytterbium and lutetium octaethylporphyrins, aggregate in benzene and the Soret bands in their absorption spectra are about 6 nm shifted to higher energies upon a hundred-fold increase in their concentrations. The aggregations of these lanthanide porphyrin complexes in non-coordinating solvents have been further verified by 1H
NMR
spectral studies. This spectral behavior can be interpreted qualitatively in terms of the model of the molecular exciton interactions with stacking of at least two prophyrins. A dimeric structure of these lanthanide porphyrin complexes has been proposed on the basis of geometrical considerations. On the contrary, the europium and gadolinium octaethylporphyrins associate very weakly in benzene in the concentration range studied. All four lanthanide porphyrin complexes interact with
pyridine
and piperidine, and the Soret bands in their absorption spectra are about 8 nm shifted to low energies as compared with their values in pure benzene.
...
PMID:Lanthanide octaethylprophyrins: preparation, association, and interaction with axial ligands. 62 34
Proton spin-lattice relaxation times of
pyridine
and 1-methylimidazole complexed on Fe(III)protoporphyrin IX dimethyl ester, Fe(III)tetraphenylporphyrin in chloroform and on metmyoglobin in 2H2O have been measured. Caused by chemical exchange of the ligand molecules into the bulk solvent phase, the decay of their MZ-magnetization is given by a superposition of two exponentials from which the mean lifetime of the complexed species can be determined. This method offers the possibility to study exchange kinetics of ligand molecules from a well defined molecular configuration. The present data are compared with the results from linewidth measurements of the bulk phase molecules. From both sets of parameters a detailed picture of the ligand exchange can be gained, particularly if spin transition of the paramagnetic organic metal complex occurs, as is the case for some ferriporphyrins. For metmyoglobin, the
NMR
result is compared with relaxation times extracted from temperature jump experiments under similar conditions.
...
PMID:Proton NMR relaxation study of the binding of pyridine and 1-methylimidazole to some ferriporphyrins and to metmyoglobin. 70 86
Zinc/acetylacetone/
pyridine
treatment has been designed as a very efficient method for removal of 2,2,2,-trichloroethyl group from phosphoesters. Internucleotide and terminal 2,2,2-trichloroethylphosphotriesters were transformed to corresponding diesters quantitatively. Much less reactive 2,2,2-trichloroethylphosphodiesters produced monoesters with ca. 90% yield. 31P
NMR
spectroscopy has been proposed as a new tool for analysis of removal of internucleotide phosphate protecting groups-a crucial step in oligonucleotides synthesis via phosphotriester approach.
...
PMID:Nucleoside 3'-phosphotriesters as key intermediates for the oligoribonucleotide synthesis. IV. New method for removal of 2,2,2-trichloroethyl group and 31P NMR as a new tool for analysis of deblocking of internucleotide phosphate protecting groups. 90 78
The interaction of 3'-O-acetyldithymidilate (pdTpdT(Ac)), thymidine-3',5'-diphosphate (pdTp) and thymidine-3'-phenyl-phosphate-5'-phosphate (pdTpPh) with 2,4,6-triisopropylbenzene sulphonyl chloride (TPS) and N,N'-dicyclohexylcarbodiimide (DCC) in
pyridine
and dimethylformamide (DMF) was studied by pulsed
NMR
spectroscopy on phosphorus nuclei. Thymidine cyclic 3',5'-pyrophosphate and dimeric pyrophosphate derivatives were shown to be the main products of the reaction of pdTp with TPS and DCC. The former shows spin AB-system with the unusually large spin-spin coupling constant about 28Hz upfield to the signals of the dimeric pyrophosphates in
NMR
spectrum. Analogous spin AB-systems with large spin-spin coupling constants (up to 32 Hz) were observed in the spectra of the reaction mixtures of pdTpdT(Ac) with TPS or DCC and of pdTpPh with TPS. These spin AB-systems were ascribed to 3',5'-cyclic pyrophosphate derivatives of pdTpdT(Ac) and pdTpPh.
...
PMID:Investigation of the mechanism of the synthesis of oligonucleotides. IX. 31P NMR spectra of the active dinucleotide derivatives and their analogs. 94 Jul 73
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