PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Propane”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2001

2,2',6,6'-Tetrachloro-4,4'-propane-2,2-diyldiphenol, 2,2',6-tribromo-4,4'-propane-2,2-diyldiphenol and 2,2',6,6'-tetrabromo-4,4'-propane-2,2-diyldiphenol.

Three flame retardants with very similar molecular structures showing three different packing patterns have been studied. The crystal structure of 2,2',6,6'-tetrachloro-4,4'-propane-2,2-diyldiphenol, C(15)H(12)Cl(4)O(2), can be described as a packing of sheets. The packing shows a very short intermolecular Cl.Cl contact distance of 3.094 (2) A between pairs of molecules inside each sheet. The crystal structure of 2,2',6-tribromo-4,4'-propane-2,2-diyldiphenol, C(15)H(13)Br(3)O(2), can be described as a packing of doubly stranded helical square tubes. These square helices are interconnected through Br...Br contacts between different helices. Finally, a previously known structure, 2,2',6,6'-tetrabromo-4,4'-propane-2,2-diyldiphenol [Simonov, Cheban, Rotaru & Bels'skii (1986). Kristallografiya, 31, 397-399], C(15)H(12)Br(4)O(2), which is the most commonly used flame retardant and which has twofold rotational symmetry, has been refined in the correct absolute configuration. The structure shows large differences from the chloro analogue with regard to packing, van der Waals distances and hydrogen-bond distances.

Crystallography, X-Ray↗
PubMed2005

Low-temperature complete combustion of a dilute mixture of methane and propane over transition-metal-doped ZrO2 catalysts: effect of the presence of propane on methane combustion.

Complete combustion of dilute methane alone or a dilute mixture of methane and propane over transition-metal (viz. Mn, Co, Cr, Fe, and Ni)-doped ZrO2 (cubic) catalysts at different temperatures (523-873 K) and a space velocity of 51,000 cm3 x g(-1) x h(-1) has been investigated for controlling methane and propane emissions from exhaust gases. The catalysts are compared for their catalytic ignition temperature and activity in the combustion of propane and methane in the presence of each other. The methane combustion activity of all the catalysts is strongly influenced by the presence of propane; it is decreased markedly. In the combustion of mixed methane and propane the Mn-doped ZrO2 and Cr-doped ZrO2 catalysts show the highest activity in the combustion of methane and propane, respectively; the Ni-doped ZrO2 shows the lowest activity in both cases. In the combustion of mixed methane and propanethe propane combustion is enhanced butthe methane combustion retarded when the Cr-doped ZrO2 and Mn-doped ZrO2 catalysts in a 1:1 ratio are used together in different ways (mixed or in layers).

Air Pollution↗
PubMed2003

Propane monooxygenase and NAD+-dependent secondary alcohol dehydrogenase in propane metabolism by Gordonia sp. strain TY-5.

A new isolate, Gordonia sp. strain TY-5, is capable of growth on propane and n-alkanes with C(13) to C(22) carbon chains as the sole source of carbon. In whole-cell reactions, significant propane oxidation to 2-propanol was detected. A gene cluster designated prmABCD, which encodes the components of a putative dinuclear-iron-containing multicomponent monooxygenase, including the large and small subunits of the hydroxylase, an NADH-dependent acceptor oxidoreductase, and a coupling protein, was cloned and sequenced. A mutant with prmB disrupted (prmB::Kan(r)) lost the ability to grow on propane, and Northern blot analysis revealed that polycistronic transcription of the prm genes was induced during its growth on propane. These results indicate that the prmABCD gene products play an essential role in propane oxidation by the bacterium. Downstream of the prm genes, an open reading frame (adh1) encoding an NAD(+)-dependent secondary alcohol dehydrogenase was identified, and the protein was purified and characterized. The Northern blot analysis results and growth properties of a disrupted mutant (adh1::Kan(r)) indicate that Adh1 plays a major role in propane metabolism. Two additional NAD(+)-dependent secondary alcohol dehydrogenases (Adh2 and Adh3) were also found to be involved in 2-propanol oxidation. On the basis of these results, we conclude that Gordonia sp. strain TY-5 oxidizes propane by monooxygenase-mediated subterminal oxidation via 2-propanol.

Alcohol Dehydrogenase↗
PubMed1986

The metabolism of 1-phenyl-2-(N-methyl-N-benzylamino)propane (benzphetamine) and 1-phenyl-2-(N-methyl-N-furfurylamino)propane (furfenorex) in man.

The metabolic fate of 1-phenyl-2-(N-methyl-N-benzylamino)propane (benzphetamine) and 1-phenyl-2-(N-methyl-N-furfurylamino)propane (furfenorex) in healthy volunteers has been investigated. Nine metabolites with traces of the unchanged drug were detected in human urine after oral administration of benzphetamine, and five metabolites were found following administration of furfenorex. The major metabolites were 1-(p-hydroxyphenyl)-2-(N-benzylamino)propane for benzphetamine and 1-phenyl-2-(N-methyl-N-gamma-valerolactonylamino)propane for furfenorex. In both cases, methamphetamine, amphetamine and their hydroxylated metabolites were also excreted as minor metabolites. Identified metabolites excreted in three days after administration of benzphetamine accounted for 30-44% of the dose and those excreted after administration of furfenorex, 31-46%.

Administration, Oral↗
PubMedDate not supplied

[Assimilation of propane and properties of propan monooxygenase from Rhodococcus erythropolis 3/89].

The ability of propane-assimilating microorganisms of the genus Rhodococcus to utilize metabolites of the terminal and subterminal pathways of propane oxidation was studied. Propane monooxygenase of Rhodococcus erythropolis 3/89 was shown to be the an inducible enzyme catalyzing epoxidation and hydroxylation of organic compounds. The optimum conditions for epoxidation of gaseous and liquid alkenes and hydroxylation of aromatic carbohydrates were found.

Catalysis↗
PubMed1978

3-Tertiary amino-1-aryloxy- or aryl-propanes and -propan-2-ols and some related compounds.

The synthesis and pharmacological activity of some 3-tertiary amino-1-aryloxy- or 1-aryl-, 1-thiophenoxy and 1-anilino-propan-2-ols and -propanes, particularly those derived from N-phenylpiperazines are described. Effect of substituents (nature/position) on the phenyl ring, the phenoxy ring as well as alteration in the hydroxylic function vis-à-vis the structure-activity relationships (SAR) are discussed. In general, the 1-aryloxy compounds have hypotensive activity--this being more pronounced in those carrying an o-substituent on the phenyl ring, while m and p-substituted derivatives have their effect primarily on the CNS. Variations in the phenoxy moiety do not significantly alter the intrinsic activity. The 1-aryl compounds, on the other hand, have significant CNS activity, which is markedly affected by the substituents on the 1-aryl residue.

1-Propanol↗
PubMed1978

beta-Adrenergic blocking agents. 18. 1-(Aryloxy)-3-(arylthioalkylamino)propan-2-ols and 1-substituted alkylthioamino-3-(aryloxy)propan-2-ols.

The synthesis is described of a seris of derivaties of 1-(aryloxy)-3-(arylthioalkylamiho)propan-2-ols and 1-(alkylthioamino)- and 1-(aralkylamino)-3-(aryloxy)propan-2-ols. These compounds were investigated for their beta-adrenoreceptor blocking properties and their selectivity of action for the cardiac beta1 receptor. The structure-activity relationships are discussed with particular reference to the effects of the sulfur, sulfoxide, and sulfone groups on beta-adrenoreceptor blocking potency and selectivity.

Adrenergic beta-Antagonists↗
PubMed2005

catena-Poly[[[N,N'-bis(salicylidene)propane-1,3-diaminato]cobalt(III)]-mu-azido] and catena-poly[[[N,N'-bis(salicylidene)propane-1,3-diaminato]cobalt(III)]-mu-thiocyanato].

The two title complexes, catena-poly[[{2,2'-[1,3-propanediylbis(nitrilomethylidyne)]diphenolato}cobalt(III)]-mu-azido], [Co(C17H16N2O2)(N3)]n, (I), and catena-poly[[{2,2'-[1,3-propanediylbis(nitrilomethylidyne)]diphenolato}cobalt(III)]-mu-thiocyanato], [Co(C17H16N2O2)(NCS)]n, (II), are isomorphous polynuclear cobalt(III) compounds. In both structures, the Co(III) atom is six-coordinated in an octahedral configuration by two N atoms and two O atoms of one Schiff base, and two terminal N or S atoms from two bridging ligands. The [N,N'-bis(salicylidene)propane-1,3-diaminato]cobalt(III) moieties are linked by the bridging ligands, viz. azide in (I) and thiocyanate in (II), giving zigzag polymeric chains with backbones of the type [-Co-N-N-N-Co]n in (I) or [-Co-N-C-S-Co]n in (II) running along the c axis.

Journal Article↗
PubMed2004

N,N'-Bis(dipiperidin-1-ylmethylene)propane-1,3-diamine and N,N'-bis(1,3-dimethylperhydropyrimidin-2-ylidene)propane-1,3-diamine.

The molecular structures of the title compounds, C(25)H(46)N(6) and C(15)H(30)N(6), respectively, show the two guanidyl moieties each connected by propyl bridges. The different substitution pattern of the guanidyl groups has no influence on the distinct localization of their C=N double bonds. Both compounds exhibit approximate twofold symmetry and the crystal packing shows no prominent hydrogen-bonding interactions.

Journal Article↗
PubMed2006

(Z)-6-{[1,3-Dihydroxy-2-(hydroxymethyl)propan-2-yliminio]methyl}-2-ethoxyphenolate, (Z)-6-{[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yliminio]methyl}-4-nitratocyclohexa-2,4-dienone monohydrate and (R,E)-2-[(1-hydroxybutan-2-ylimino)methyl]phenol.

The title compounds C(13)H(19)NO(5), C(11)H(14)N(2)O(6)xH(2)O and C(11)H(15)NO(2), respectively, have been derived from 3-ethoxysalicylaldehyde, 5-nitrosalicylaldehyde and salicylaldehyde, respectively. The C-O and N-C bond distances, and three hydrogen bonds formed by the phenolate O atom, show that the zwitterionic form exists in the first compound. The second compound is transformed to the quinoid form as a result of resonance between the zwitterionic form and the nitro group. The third compound exists in the phenol-imine form, with appropriate C-N and C-O bond distances.

Heterocyclic Compounds, 2-Ring↗
PubMedDate not supplied

Synthesis of new 1-(amino)-3-[(1,5-diphenyl-1H-1,2,4-triazol-3-yl) oxy] propan-2-ol and 1-[(1,5-diphenyl- 1H- 1,2,4-triazol-3-yl) oxy]-3-(4-arylpiperazin-1-yl) propan-2-ol derivatives with an expected beta-adrenolytic activity.

3-(Oxiran-2-ylmethoxy)-l ,5-diphenyl-lH-1,2,4-triazole [I] was obtained in the reaction of 1,5-di-phenyl-IH-1,2,4-triazol-3-ol with 2-(chloromethyl) oxirane. Then I was converted into the corresponding aminoalkanol derivatives of 1,5-diphenyl-IH-1,2,4-triazol-3-ol, IIa,b -VIIa,b. Molecular structure of I was confirmed by an X- ray structure analysis. The receptor affinities for IVa, VIIa were determined.

Adrenergic beta-Antagonists↗
PubMed2005

In situ (1)H and (13)C MAS NMR kinetic study of the mechanism of H/D exchange for propane on zeolite H-ZSM-5.

The kinetics of hydrogen (H/D) exchange between Brønsted acid sites of zeolite H-ZSM-5 and variously deuterated propanes (propane-d(8), propane-1,1,1,3,3,3-d(6), propane-2,2-d(2)) have been monitored in situ by (1)H MAS NMR spectroscopy within the temperature range of 503-556 K. The contribution of intramolecular hydrogen transfer to the H/D exchange in the adsorbed propane was estimated by monitoring the kinetics of (13)C-labeled carbon scrambling in propane-2-(13)C in situ with (13)C MAS NMR at 543-573 K. Possible mechanisms of the exchange have been verified on the basis of the analysis of the variation of protium concentration in both the methyl and the methylene groups of propane in dependence of the reaction time. The main route of the exchange consists of a direct exchange of the acidic OH groups of the zeolite with either the methyl groups or the methylene group presumably with a pentacoordinated carbonium ion intermediate. The assumption that the intramolecular H scrambling between the methyl groups and the methylene group of propane via carbenium-ion-type intermediates is the fastest process among the other possible routes does not account for the experimental kinetics of H/D exchange for propanes with different initial contents and locations of deuterium in a propane molecule. The rate constant (k(3)) for intramolecular H/D exchange between the methyl and the methylene groups is 4-5 times lower compared to those of the direct exchange of both the methyl (k(1)) and the methylene (k(2)) groups with Brønsted acid sites of the zeolite, the k(1) being ca. 1.5 times higher than k(2). At lower temperature (473 K), the exchange is slower, and the expected difference between k(1) and k(2) is more essential, k(1) = 3k(2). This accounts for earlier observed regioselectivity of the exchange for propane on H-ZSM-5 at 473 K. Faster direct exchange with the methyl groups compared to that with the methylene groups was attributed to a possible, more spatial accessibility of the methyl groups for the exchange. Similar activation energies for H and C scramblings with a 2 times more rapid rate of H scrambling was rationalization by the proceeding of these two processes through an isopropyl cation intermediate, as in classical carbenium ion chemistry.

Adsorption↗