Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q9UMR3 (NMR)
 150,598 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The 13C- and 31P-NMR spectra and DSC thermograms of unsonicated dispersions consisting of phospholipids of varying methylation stages of the propanolamine head group were investigated. Methylation of the head group was accompanied by a corresponding reduction in the phase transition temperatures. In the liquid crystalline state the 31P-anisotropy of the chemical shift is about equal for all studied compounds, demonstrating that the motion of the phosphate group is not influenced by modifications of the propanolamine group.
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PMID:NMR and calorimetric studies of changes in phase transition of head group modified phospholipids. 59 70

Analytical methods were developed to determine whether there was less than one ppm of II in IV. Purified IV contained a compound with the same GC retention time as authentic II on OV-17 and Silar 10C columns, using a FID or a nitrogen/phosphorus detector. The GC-coupled mass spectra contained major peaks at m/e 251 and 167 and the GC-coupled methane CI spectra gave the quasi-molecular ion, m/e 282. However, the CI selected ion monitor indicated three compounds at m/e 282. The nitrosamine II was separated from IV by HPLC on muBondapak C18. The GC-coupled mass spectra of the HPLC nitrosamine fraction had peaks at m/e 251 and 167 and other peaks for a compound of greater MW than II, although the GC retention times were the same. Evidence for II and a decrease in the detection limit to one ppm was obtained with a TEA interfaced with a HPLC. To determine if II was formed from IV, it was exposed to ozone at -78 degrees C in methylene chloride. The DSC, IR and NMR of the product were coincident with those of the standard of II. In other experiments, IV in methylene chloride was exposed to light and dry air in the presence and absence of methylene blue. The PMR and 13C NMR of the product formed in the presence of methylene blue were the same as that of II. It is postulated that this nitrosamine was formed by a singlet oxygen mechanism.
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PMID:The analysis and source of 1-diphenylmethyl-4-nitrosopiperazine in 1-diphenylmethyl-4-[(6-methyl-2-pyridyl) methyleneamino]piperazine: a case history. 68 Jul 47

Etoposidum: 4'-demethyl-epipodophyllotoxin-beta-D-ethylidene-pyrano-glucoside or VP-16-213 in trade name is a semisynthetic antineoplastic drug. We found that it has two different kinds of crystal form named crystal A and B, they were crystallized from methanol and ethanol respectively. Their structures were identified by NMR and MS. They have similar infrared spectrum but with repeatable small differences. The powder X-ray diffraction pattern of the two kinds of crystals are quite different. The DSC curve of crystal A is rather smooth but that of crystal B shows abnormal positive and negative peaks. On the other hand, they have the same kind of smooth TGA curves. This fact shows that the positive and negative peaks are not the result of chemical reaction. After heating crystal B in DSC oven at 190 degrees C and 250 degrees C, respectively, their IR spectra showed that the pattern of the first one did not change, but the second one changed to the spectrum of crystal A. This reveals that the positive peak is due to the melting of crystal B and the negative peak is the result of the formation of crystal A. The pharmaceutic preparation of VP-16-213 is its glycerine solution, so the crystal form does not influence the efficacy of the drug.
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PMID:[Study of the polymorph of etoposidum]. 148 78

The action of the relaxing agent dantrolene on dipalmitoylphosphatidylcholine (DPPC) model membranes in the presence and absence of the general anesthetic halothane has been investigated by DSC and 31P-NMR. Dantrolene has a weak effect on both the thermodynamic and NMR parameters of the pure model membrane. When halothane is present in the system, the relaxing agent acts to counterbalance the strong anesthetic-induced membrane perturbation. This is reflected in DSC experiments by a change of the enthalpy variation (delta H) and of the main gel-to-fluid phase transition temperature (Tc) towards the values of the pure lipid system. The amount of halothane-induced small tumbling vesicles, as detected by 31P-NMR by the superposition of an isotropic line on a lamellar-type powder spectrum, is considerably reduced upon dantrolene addition. This means that the relaxing agent "cures" the membrane de-structuring action promoted by halothane. Membranes first treated with dantrolene are also protected from the halothane perturbation. So, the relaxing agent is both "curative" and "preventative" against halothane. The optimum effect is obtained for 1 dantrolene molecule per ca 34 halothane molecules. The mechanisms of action were discussed in relation to membrane fluidity.
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PMID:Dantrolene inhibits halothane-induced membrane reorganization. A study using 31P-NMR and differential scanning calorimetry. 151 57

This research presents the results of a series of stability studies on freeze-dried formulations of human growth hormone (hGH). Chemical decomposition via methionine oxidation and asparagine deamidation as well as irreversible aggregation are characterized by HPLC. Water sorption isotherms, DSC thermograms, and pulsed proton NMR data are also obtained. No glass transition temperatures are observed in the temperature range of the stability studies. The pulsed NMR data suggest onset of greater mobility in the solid at a water content slightly higher than BET "monolayer" level. Stability of freeze-dried solids at 25 degrees C and 40 degrees C is studied as a function of residual moisture and exposure to oxygen. Formulations with and without a glycine/mannitol excipient system are studied. Significant levels of chemical decomposition and irreversible aggregation occur under most conditions with the effects of residual water content and "headspace oxygen" strongly dependent on the formulation. At low water content with minimal oxygen in the vial headspace, the glycine/mannitol formulation yields optimum stability. However, for either high water content or high oxygen content in the vial, stability of hGH without excipients is superior. The qualitative effect of residual moisture on stability depends on the temperature of the stability study. Generally, the stability of a sample adjusted to a given water content by desorption (during freeze-drying) is identical to the stability of a sample prepared by sorption of water on to a previously highly dried sample.
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PMID:Formulation and stability of freeze-dried proteins: effects of moisture and oxygen on the stability of freeze-dried formulations of human growth hormone. 159 71

Polyurethane fibers were synthesized and characterized by IR, 1H NMR, DSC, and GPC. Their properties as fiber were compared with commercially available sutures of polypropylene, polyamide, polyester, and silk.
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PMID:Synthesis and characterization of aliphatic polyurethane fiber: a potential suture material. 181 18

Organomercury(II) complexes involving 6-thioguanine, of the type p-XC6H4HgL (Fig. 1) [LH = 6-thioguanine; X = Me, MeO, NO2], have been synthesized and characterized. Conductance measurements indicate that the complexes are nonelectrolytes. From IR and UV studies, it is concluded that 6-thioguanine acts as a bidentate ligand, coordinating through the 6-thione group and deprotonation of N-7. 1H and 13C NMR support the stoichiometry of the complexes. From thermal studies (TG and DSC) various kinetic and thermodynamic parameters for thermal degradation have been enumerated. In addition, the fragmentation pattern of the complexes have been analyzed on the basis of mass spectra. The p-MeC6H4HgL and p-MeOC6H4HgL complexes display significant activity against L1210 leukemia cells.
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PMID:Organomercury(II) complexes of 6-thioguanine: synthesis, characterization, and biological studies. 185 22

Seven complexes containing neutral isoorotic and 2-thioisoorotic acids, as well as thiocyanate and chloride anions as lignands, have been synthesized and characterized by means of both spectral (IR, 1H, and 13C NMR) and thermal (TG and DSC) methods, as well as conductivity measurements. Spectral data suggest that any binding metal-ligand mode for uracil derivatives is not easy to propose. Therefore, isoorotic ligands must link through some oxygen atom. Likewise, 2-thioisoorotic acid seems to be [N,S] bonded in Pd(II) and Pt(IV) complexes, whereas for Hg(II) complex a distorted tetrahedral HgCl2S2 structure has been proposed. In the cadmium complex, the metal ion exhibits a CdCl2O2 coordination sphere. Antimicrobial activities of the complexes against Pseudomonas sp, E. coli, Proteus sp, Salmonella sp, Micrococcus sp, Staphylococcus sp, Bacillus sp and Candida sp were performed as a previous step in the study of their biological activity.
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PMID:Palladium, platinum, cadmium, and mercury complexes with neutral isoorotic and 2-thioisoorotic acids: IR and NMR spectroscopies, thermal behavior and biological properties. 194 Aug 99

1,2-Dimethyl-3-hydroxy-4-pyridone (1), a crystalline oral iron chelator, forms an acetic acid solvate (2) on recrystallization from acetic acid and carbon tetrachloride. Compound 2 forms compact prisms, and 1 forms needles from water (mp 274 degrees C). The X-ray powder diffraction patterns of 1 and 2 differ, indicating distinct solid phases. Compound 2 has an extra DSC endotherm at 82 degrees C that is accompanied by a weight loss of 29% in TGA, corresponding to the desolvation of a 1:1 acetic acid solvate. Comparison of the solid-state 13C NMR of 1 and 2 revealed two additional peaks for 2 at 20.3 and 175.6 ppm, characteristic of -CH3 and -COOH, respectively, of acetic acid. The integrated intensities confirmed the 1:1 stoichiometry between 1 and acetic acid. However, 2 underwent desolvation in air at 25 degrees C as suggested by a change in its appearance to opaque crystals and as confirmed by X-ray powder diffraction, DSC, and TGA. Desolvation of 2 at 25 degrees C was a zero-order process with a rate constant of 6.9 mumol.h-1. X-ray powder diffraction showed that crystals or compacted discs of 1 are converted to 2 in contact with glacial acetic acid (A), whereas crystals or discs of 2 are converted to 1 in contact with water. The intrinsic dissolution rate (J) and the apparent solubility (Cs) of compacted discs of 1 and 2 were measured in water at 25 degrees C, and the following relations were determined: J(2)/J(1) = 1.39 and Cs(2)/Cs(1) = 1.70.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Solid state properties of an oral iron chelator, 1,2-dimethyl-3-hydroxy-4-pyridone, and its acetic acid solvate. I: Physicochemical characterization, intrinsic dissolution rate, and solution thermodynamics. 194 68

To clarify the mechanism of interaction of dental adhesive monomers with biological membranes at the molecular level, we studied the interaction of methacryloyloxydecyl dihydrogen phosphate (MDP) and methacrylic acid (MAA) with the dipalmitoylphosphatidylcholine (DPPC) liposome system using NMR and DSC. MDP-DPPC interaction became apparent through broadening of the DPPC phase transition as pH decreased, finally the enthalpy of MDP-DPPC (1:1 mol ratio) reduced to zero at pH 2.5. Proton chemical shifts of MDP enhanced shielding and proton signals due to the phosphatidylcholine polar group (O-CH2-CH2-N bond) of DPPC were observed. MAA-DPPC interaction was smaller than that of MDP-DPPC, even at low pH. It was concluded that the strong hemolytic activity of MDP may be due to its interaction with the phospholipid bilayers of erythrocyte membranes.
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PMID:Hemolysis mechanism of dental adhesive monomer (methacryloyloxydecyl dihydrogen phosphate) using a phosphatidylcholine liposome system as a model for biomembranes. 209 83


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