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Molecules (Basel, Switzerland) Nov 2020Recently discovered hybrid perovskites based on hypophosphite ligands are a promising class of compounds exhibiting unusual structural properties and providing...
Recently discovered hybrid perovskites based on hypophosphite ligands are a promising class of compounds exhibiting unusual structural properties and providing opportunities for construction of novel functional materials. Here, we report for the first time the detailed studies of phonon properties of manganese hypophosphite templated with methylhydrazinium cations ([CHNHNH][Mn(HPO)]). Its room temperature vibrational spectra were recorded for both polycrystalline sample and a single crystal. The proposed assignment based on Density Functional Theory (DFT) calculations of the observed vibrational modes is also presented. It is worth noting this is first report on polarized Raman measurements in this class of hybrid perovskites.
Topics: Calcium Compounds; Cations; Density Functional Theory; Ions; Manganese; Materials Testing; Microscopy, Confocal; Models, Molecular; Monomethylhydrazine; Oxides; Phosphites; Quantum Theory; Software; Spectrophotometry, Infrared; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Temperature; Titanium; Vibration
PubMed: 33182446
DOI: 10.3390/molecules25215215 -
Journal of the American Society For... May 2007Protonated ammonia and hydrazines (MH(+)) form complexes with ketones and the differences in masses and mobilities of the resulting ions, MH(+)(ketone)(n), are...
Protonated ammonia and hydrazines (MH(+)) form complexes with ketones and the differences in masses and mobilities of the resulting ions, MH(+)(ketone)(n), are sufficient for separation in an ion mobility spectrometer at ambient pressure. The highest mass ion for any of the protonated molecules is obtained when the ketone is present at elevated concentrations in the supporting atmosphere of both the source and drift regions of the spectrometer so that an ion maintains a discrete composition and mobility. The sizes of the ion-molecule complexes were found to depend on the number of H atoms on the protonated nitrogen atom--four for ammonia, three for hydrazine, two for monomethylhydrazine, and one for 1,1-dimethylhydrazine, and the drift times of these ions were proportional to the size of the ion-molecule complex. Unexpected side products, including protonated hydrazones and azines, and associated ketone clusters, were isolated to a single drift tube containing ceramic parts and could not, from CID studies, be attributed to gas-phase ion chemistry. These findings illustrate that mobility resolution of ions in IMS and IMS/MS experiments can be enhanced through chemical modification of the supporting gas atmosphere without changes in the core ion.
Topics: Air; Air Pressure; Ammonia; Hydrazines; Ketones; Mass Spectrometry; Protons
PubMed: 17376700
DOI: 10.1016/j.jasms.2007.01.014 -
Applied Microbiology Jan 1965The sporicidal activity of components used in liquid and solid rocket propellants was tested by use of spores of Bacillus subtilis dried on powdered glass. Liquid...
The sporicidal activity of components used in liquid and solid rocket propellants was tested by use of spores of Bacillus subtilis dried on powdered glass. Liquid propellant ingredients tested were N(2)O(4), monomethylhydrazine and 1,1-dimethylhydrazine. N(2)O(4) was immediately sporicidal; the hydrazines were effective within several days. Solid propellants consisted of ammonium perchlorate in combination with epoxy resin (EPON 828), tris-1-(2-methyl) aziridinyl phosphine oxide, bis-1-(2-methyl) aziridinyl phenylphosphine oxide, and three modified polybutadiene polymers. There was no indication of appreciable sporicidal activity of these components.
Topics: Bacillus subtilis; Dimethylhydrazines; Hydrazines; Oxides; Research; Space Flight; Spores; Spores, Bacterial
PubMed: 14264838
DOI: 10.1128/am.13.1.10-14.1965 -
The American Journal of Pathology Oct 1996Folate deficiency enhances colorectal carcinogenesis in dimethylhydrazine-treated rats. Folate is an important mediator of DNA methylation, an epigenetic modification of...
Folate deficiency enhances colorectal carcinogenesis in dimethylhydrazine-treated rats. Folate is an important mediator of DNA methylation, an epigenetic modification of DNA that is known to be dysregulated in the early stages of colorectal cancer. This study investigated the effect of dimethylhydrazine on DNA methylation of the colonic p53 gene and the modulation of this effect by dietary folate. Sprague-Dawley rats were fed diets containing 0, 2, 8, or 40 mg of folate/kg of diet. Five weeks after diet initiation, dimethylhydrazine was injected weekly for fifteen weeks. Folate-depleted and folate-replete control animals did not receive dimethylhydrazine and were fed the 0- and 8-mg folate diets, respectively. The extent of p53 methylation was determined by a quantitative HpaII-polymerase chain reaction. In exons 6 and 7, significant p53 hypomethylation was observed in all dimethylhydrazine-treated rats relative to controls (P < 0.01), independent of dietary folate. In exon 8, significant p53 hypomethylation was observed only in the dimethylhydrazine-treated folate-depleted rats compared with controls (P = 0.038) and was effectively overcome by increasing levels of dietary folate (P = 0.008). In this model, dimethylhydrazine induces exon-specific p53 hypomethylation. In some exons, this occurs independent of dietary folate, and in others, increasing levels of dietary folate effectively override the induction of hypomethylation in a dose-responsive manner. This may be a mechanism by which increasing levels of dietary folate inhibit colorectal carcinogenesis.
Topics: Animals; Colon; Colorectal Neoplasms; DNA Methylation; Disease Models, Animal; Exons; Folic Acid; Genes, p53; Male; Monomethylhydrazine; Precancerous Conditions; Rats; Rats, Sprague-Dawley
PubMed: 8863662
DOI: No ID Found -
Blood Mar 1992We have previously shown that excess unpaired alpha- and beta-globin chains in severe alpha- and beta-thalassemia interacting with the membrane skeleton induce different...
We have previously shown that excess unpaired alpha- and beta-globin chains in severe alpha- and beta-thalassemia interacting with the membrane skeleton induce different changes in membrane properties of red blood cells (RBCs) in these two phenotypes. We suggest that these differences in membrane material behavior may reflect the specificity of the membrane damage induced by alpha- and beta-globin chains. To further explore this hypothesis, we sought in vitro models that induce similar membrane alterations in normal RBCs. We found that treatment of normal RBCs with phenylhydrazine produced rigid and mechanically unstable membranes in conjunction with selective association of oxidized alpha-globin chains with the membrane skeleton, features characteristic of RBCs in severe beta-thalassemia. Methylhydrazine, in contrast, induced selective association of oxidized beta-globin chains with the membrane skeleton and produced rigid but hyperstable membranes, features that mimicked those of RBCs in severe alpha-thalassemia. These findings suggest that consequences of oxidation induced by globin chains are quite specific in that those agents that cause alpha-globin chain accumulation at the membrane produce rigid but mechanically unstable membranes, whereas membrane accumulation of beta-globin chains results in rigid but mechanically stable membranes. These in vitro experiments lend further support to the hypothesis that membrane-associated alpha- and beta-chains induce oxidative damage to highly specific different skeletal components and that the specificity of this skeletal damage accounts for the differences in material membrane properties of these oxidatively attacked RBCs and perhaps of alpha- and beta-thalassemic RBCs as well.
Topics: Erythrocyte Deformability; Erythrocyte Membrane; Globins; Humans; Methylphenazonium Methosulfate; Monomethylhydrazine; Oxidation-Reduction; Phenylhydrazines; Thalassemia
PubMed: 1547347
DOI: No ID Found -
Proceedings of the National Academy of... Oct 1999Soluble glucose dehydrogenase (s-GDH) from the bacterium Acinetobacter calcoaceticus is a classical quinoprotein. It requires the cofactor pyrroloquinoline quinone (PQQ)...
Soluble glucose dehydrogenase (s-GDH) from the bacterium Acinetobacter calcoaceticus is a classical quinoprotein. It requires the cofactor pyrroloquinoline quinone (PQQ) to catalyze the oxidation of glucose to gluconolactone. The precise catalytic role of PQQ in s-GDH and several other PQQ-dependent enzymes has remained controversial because of the absence of comprehensive structural data. We have determined the crystal structure of a ternary complex of s-GDH with PQQ and methylhydrazine, a competitive inhibitor of the enzyme. This complex, refined at 1.5-A resolution to an R factor of 16.7%, affords a detailed view of a cofactor-binding site of s-GDH. Moreover, it presents the first direct observation of covalent PQQ adduct in the active-site of a PQQ-dependent enzyme, thereby confirming previous evidence that the C5 carbonyl group of the cofactor is the most reactive moiety of PQQ.
Topics: Binding Sites; Crystallography, X-Ray; Glucose Dehydrogenases; Models, Chemical; Models, Molecular; Molecular Sequence Data; Monomethylhydrazine; Protein Binding; Protein Conformation; Quinolones; Quinones
PubMed: 10518528
DOI: 10.1073/pnas.96.21.11787 -
British Journal of Cancer Nov 19741,2-Dimethylhydrazine, in contrast to 1-methylhydrazine, is a potent carcinogen for the colon in rats and mice. 1,2-[(14)C]Dimethylhydrazine was administered to rats and...
1,2-Dimethylhydrazine, in contrast to 1-methylhydrazine, is a potent carcinogen for the colon in rats and mice. 1,2-[(14)C]Dimethylhydrazine was administered to rats and mice in doses which are carcinogenic following a single dose in the former species, or carcinogenic on repeated administration in the latter species, and the rate of (14)CO(2) exhalation was measured. Exhalation of (14)CO(2) was also studied after administration of single doses of 1-[(14)C]methylhydrazine to mice. Incorporation of radioactivity into the nucleic acids of a variety of organs was found at a time after injection (about 6 h) when (14)CO(2) production from both compounds was virtually complete. Methylation of nucleic acids of liver and colon, as indicated by the formation of 7-methylguanine, was observed after treatment with 1,2-dimethylhydrazine and to a smaller extent by a factor of about 10 after treatment with 1-methylhydrazine. Less than 1% of a single dose of 1,2-[(14)C]dimethylhydrazine was excreted in the bile of rats as determined by chemical and radioactivity assays. The similarities of the biological and biochemical actions of 1,2-dimethylhydrazine with those of some nitroso compounds and of cycasin (methylazoxymethanol glucoside) are emphasized.
Topics: Alkylation; Animals; Bile; Carbon Dioxide; Colon; Dimethylhydrazines; Female; Guanine; Hydrazines; Liver; Male; Mice; Monomethylhydrazine; Nucleic Acids; Rats
PubMed: 4469196
DOI: 10.1038/bjc.1974.218 -
The Journal of Biological Chemistry Dec 1990Methylhydrazine oxidation promoted by horseradish peroxidase-H2O2 or ferricyanide led to the generation of high yields of methyl radicals and to the formation of...
Methylhydrazine oxidation promoted by horseradish peroxidase-H2O2 or ferricyanide led to the generation of high yields of methyl radicals and to the formation of 7-methylguanine and 8-methylguanine upon interaction with calf thymus DNA. Methyl radicals were identified by spin-trapping experiments with alpha-(4-pyridyl-1-oxide)-N-tert-butyl nitrone and tert-nitrosobutane. The methylated guanine products were identified in the neutral hydrolysates of treated DNA by high pressure liquid chromatography (HPLC) analysis and spiking with authentic samples. The structure of 8-methylguanine, a product not previously reported in enzymatic systems, was confirmed by HPLC chromatography, UV absorbance, and mass spectrometry. The formation of 8-methylguanine suggests a possible role for carbon-centered radicals as DNA-alkylating agents.
Topics: Alkylation; DNA; Electron Spin Resonance Spectroscopy; Free Radicals; Guanine; Horseradish Peroxidase; Hydrolysis; Mass Spectrometry; Monomethylhydrazine; Oxidation-Reduction; Spectrophotometry, Ultraviolet
PubMed: 2176204
DOI: No ID Found -
The Journal of Investigative Dermatology Jun 1966Finely divided methylhydrazine sulfate was fed to 42 rats at a concentration of 300 mg per kg of ground commercial diet. After 42 days most of the rats developed...
Finely divided methylhydrazine sulfate was fed to 42 rats at a concentration of 300 mg per kg of ground commercial diet. After 42 days most of the rats developed hyperkeratosis and edema of the terminal 2-6 cm of the tail. Twenty-five rats fed longer than 98 days all developed tail tip gangrene varying in length from 0.4 to 2.5 cm. Since 24 control rats which were fed the ground commercial diet grew satisfactorily and did not develop any alterations in the skin of the tail, the tail tip gangrene is ascribed to the presence of MHS in the diet. In view of the presence of epidermal hyperplasia and edema in every instance, and the occurrence of acute folliculitis in a majority of test rats, the tail tip gangrene is believed to be due to epithelial alterations rather than an injury of the blood vessels. This experimental model may prove useful for epidermal studies, because MHS fed rats are active and energetic. Secondly, the MHS skin changes apparently can be produced more rapidly than with diets deficient in unsaturated fatty acids.
Topics: Animals; Gangrene; Male; Monomethylhydrazine; Rats; Rats, Sprague-Dawley; Skin; Tail
PubMed: 25622423
DOI: 10.1038/jid.1966.83 -
British Journal of Cancer Sep 1974Activities of N-acetyl-β-D-glucosaminidase, N-acetyl-β-D-galactosaminidase, β-D-galactosidase and α-L-fucosidase were measured in rat colonic tumours induced by...
Activities of N-acetyl-β-D-glucosaminidase, N-acetyl-β-D-galactosaminidase, β-D-galactosidase and α-L-fucosidase were measured in rat colonic tumours induced by 1,2-dimethylhydrazine. Tumours varied considerably in their enzyme content, not only from different animals but also from the same animals. Enzymatic heterogeneity among tumours appeared to be related to their site of origin in the colon. The descending colon, which after the DMH treatment showed a significant increase in the levels of glycosidases, also gave rise to a larger number of adenocarcinomata than other parts of the colon. The relative changes in the activities of four glycosidases seemed to show a good correlation.
Topics: Animals; Colonic Neoplasms; Galactosidases; Glucosidases; Glycoside Hydrolases; Hexosaminidases; Hydrazines; Injections, Subcutaneous; Intestinal Mucosa; Kinetics; Male; Monomethylhydrazine; Neoplasms, Experimental; Rats
PubMed: 4451627
DOI: 10.1038/bjc.1974.186