Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Octanes”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 73 records · Page 4Linked to original sources
PubMed2001

The solubility of gases and vapours in dry octan-1-ol at 298 K.

Ostwald solubility coefficients of 74 compounds in dry octan-1-ol at 298 K have been determined, and have been combined with literature values and additional values we have calculated from solubilities in dry octan-1-ol and vapour pressures to yield a total of 161 log L(OctOH) values at 298 K. These L(OctOH) values are identical to gas-to-dry octan-1-ol partition coefficients, often denoted as K(OA). Application of the solvation equation of Abraham to 124 values as a training set yielded a correlation equation with n = 124, S.D. = 0.125, r2 = 0.9970 and F = 7731. This equation was then used to predict 32 values of log L(OctOH) as a test set, giving a standard deviation, S.D. of 0.131, an average absolute deviation of 0.085 and an average deviation of -0.009 log units. The solvation equation for the combined 156 log L(OctOH) values was log L(OctOH) = -0.120 - 0.203R2 + 0.560pi2(H) + 3.560 sum(alpha2(H)) + 0.702 sum(beta2(H)) + 0.939 logL16, n =156, r2 = 0.9972, S.D. = 0.125, F = 10573, where, n is the number of data points (solutes), r the correlation coefficient, S.D. the standard deviation and F is the F-statistic. The independent variables are solute descriptors as follows: R2 is an excess molar refraction, pi2(H) the dipolarity/polarisability, sum(alpha2(H)) the overall or summation hydrogen-bond acidity, sum(beta2(H)) the overall or summation hydrogen-bond basicity and L16 is the Ostwald solubility coefficient on hexadecane at 298 K. The equation is consistent with similar equations for the solubility of gases and vapours into methanol, ethanol and propan-1-ol. It is suggested that the equation can be used to predict further values of log L(OctOH), for which the solute descriptors are known, to within 0.13 log units.

1-Octanol↗
PubMed2005

Structure and stability of silica particle monolayers at horizontal and vertical octane-water interfaces.

Monolayers of silica particles at horizontal and vertical octane-water interfaces have been studied by microscopy. It is found that their structure and stability depend strongly on the particle hydrophobicity. Very hydrophobic silica particles, with a contact angle of 152 degrees measured through the water, give well-ordered monolayers at interparticle distances larger than 5 particle diameters which are stable toward aggregation and sedimentation. In contrast, monolayers of less-hydrophobic particles are disordered and unstable. Two-dimensional particle sedimentation has been observed in the case of vertical monolayers. The results have been analyzed with a simple two-particle model considering the sedimentation equilibrium as a balance between the long-range electrostatic repulsion through the oil, the gravity force, and the capillary attraction due to deformation of the fluid interface around particles. The value of the charge density at the particle-octane interface, 14.1 muC/m(2), found for the most hydrophobic particles is reasonable. It drastically decreases for particles with lower hydrophobicity, which is consistent with the order-disorder transition in monolayer structure reported by us before. The pair interactions between particles at a horizontal octane-water interface have been analyzed including the capillary attraction due to undulated three-phase contact line caused by nonuniform wetting (the contact angle hysteresis). The results are in agreement with the great stability of very hydrophobic silica particle monolayers detected experimentally, even at low pH at the point of zero charge of the particle-water interface, and with the aggregated structure of hydrophilic particle monolayers.

Journal Article↗
PubMed2006

Effects of d-orbital occupancy on the geometry of the trigonal-bipyramidal complexes [M(II)Cl3(Hdabco)(dabco)]n, where M is Mn, Co, Ni or Cu and dabco is 1,4-diazabicyclo[2.2.2]octane.

Geometric data from (1-aza-4-azoniabicyclo[2.2.2]octane-kappaN(1))(1,4-diazabicyclo[2.2.2]octane-kappaN1)trichloromanganese(II), [MnCl3(C6H13N2)(C6H12N2)] or [MnCl3(Hdabco)(dabco)] (dabco is 1,4-diazabicyclo[2.2.2]octane), and the cobalt(II) analogue, [CoCl3(C6H13N2)(C6H12N2)], have been combined with previously reported data for the Ni and Cu analogues to show that bond-length trends across the isotypal series are consistent with a high-spin trigonal-bipyramidal system. As each transition metal is positioned on a D3 site in the space group R32 (No. 155), two bond lengths fully define each trigonal-bipyramidal coordination geometry [Mn-Cl = 2.3903 (7) A and Mn-N = 2.367 (2) A, and Co-Cl = 2.3080 (8) A and Co-N = 2.269 (3) A].

Journal Article↗
PubMed1998

Synthesis and muscarinic activity of a series of quinolines and naphthalenes with a 1-azabicyclo[3.3.0]octane moiety.

In order to discover a medicine effective against Alzheimer's disease, we synthesized a series of quinoline derivatives having a characteristic 1-azabicyclo[3.3.0]octane amine ring, and performed pharmacological evaluation of them. Acetylcholine esterase inhibitory activities of these derivatives were unexpectedly weak. Tests for central nervous muscarinic cholinergic receptor binding affinity indicated that these compounds had higher affinities to muscarinic M1 receptors than to M2 receptors. A series of naphthalene derivatives substituted with the 1-azabicyclo[3.3.0]octane ring were also synthesized and muscarinic M1 and M2 receptor binding affinity determined. These compounds had much higher affinity for M1 receptors than the quinoline derivatives, and 1-[N-(1-azabicyclo[3.3.0]octan-5-yl)methyl-N-methylamino]-4-nitronaph tha lene showed the highest affinity and selectivity. The ability of this compound to improve cognitive function was assessed using the passive avoidance test in scopolamine-induced mice.

Animals↗
PubMed1999

Synthesis and muscarinic activity of novel aniline derivatives with a 1-azabicyclo[3.3.0]octane moiety.

In order to develop drugs effective against Alzheimer's disease, we synthesized a series of aniline derivatives having a characteristic cyclic amine, 1-azabicyclo[3.3.0]octane ring, and evaluated their binding affinity for the central muscarinic cholinergic receptor. Among these compounds which showed high affinity to the M1 receptor, N-[2-(1-Azabicyclo[3.3.0]octan-5-yl)ethyl]-2-nitroaniline (9f fumarate, SK-946) showed the highest affinity. The ability of this compound to improve cognitive function was assessed using the passive avoidance test in scopolamine-induced dementia mice. Some anilines with a 1-azabicyclo[3.3.1]nonane ring were also synthesized by the ring expansion of the 1-azabicyclo[3.3.0]octane ring, and showed a high affinity for the central muscarinic cholinergic receptor.

Aniline Compounds↗
PubMed1990

omega-Dialkylaminoalkyl ethers of 6-(benzyl or phenyl)-1,3,3-trimethyl-2-oxabicyclo [2.2.2]octan-6-ol with platelet antiaggregating and local anesthetic activities.

The synthesis of 1,3,3-trimethyl-6-phenyl-2-oxabicyclo[2.2.2]octan-6-ol 2 and 6-benzyl-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-ol 3 starting from (+)-1,3,3-trimethyl-2-oxabicyclo[2.2.2]octan-6-one and phenylmagnesium bromide or benzylmagnesium chloride, respectively, is described. Alcohols 2 and 3 gave a series of omega-dialkylaminoalkyl ethers 4 by reaction as sodium salts with omega-chloroalkyldialkylamines in toluene solution. Some compounds 4, in particular those derived from alcohol 2, showed a strong platelet antiaggregating activity in vitro, superior to that of acetylsalicylic acid, as well as in general an appreciable local anesthetic activity and a weak sedative effect in mice.

Anesthesia↗
PubMed1979

Derivatives of 1,2,3,3-tetramethyl-2-azabicyclo[2.2.2]octan-5-endo-ol with antiarrhythmic and other activities. II.

Cyanoethylation of 1,2,3,3-tetramethyl-2-azabicyclo[2.2.2]octan-5-endo-ol, followed by LiAlH4 reduction and reaction with acyl chlorides, gave a series of amides derived from 5-endo-(3-aminopropoxy)-1,2,3,3-tetramethyl-2-azabicyclo[2.2.2]octane. The syntheses of N-methyl, N,N-dimethyl and N,N-dipropargyl derivatives of the afore mentioned amine, as well as of 5-endo-methylcarbamoyloxy- and 5-endo-phenylcarbamoyloxy-1,2,3,3-tetramethyl-2-azabicyclo[2.2.2]octane, are also described. Strong antiarrhythmic and local anesthetic activity was observed in two amides; an urethane showed antiarrhythmic activity only.

Animals↗
PubMedDate not supplied

The biodistribution and metabolic fate of inhaled 11C-octanal in the rat after acute exposure.

Rats were nose exposed to an atmosphere containing 11.4 ppm of 11C-octanal for 2 min. Inhaled octanal was absorbed from the lungs in a biphasic manner and the greatest concentration of octanal occurred in most tissues at 5 min. Tissue activities calculated on the basis of the administered dose and on the radiolabel retained until the animal was killed indicated a redistribution of the radiolabel as metabolic products after 20 min. The labeled carbon was eliminated in a biphasic manner as 11CO2, which accounted for essentially all of the activity lost by the exposed rats.

Aldehydes↗
PubMed1980

Derivatives of 1,2,3,3-tetramethyl-2-azabicyclo[2,2,2]octan-5-trans-ol with antiarrhythmic and other activities. V.

A series of N,N-dialkyl 5-trans-carbamoyloxy-1,2,3,3-tetramethyl-2-azabicyclo [2,2,2]octanes was prepared by reaction of 1,2,3,3-tetramethyl-2-azabicyclo [2,2,2]octan-5-trans-ol with phosgene, followed by aminolysis of the resulting chlorocarbonate with aliphatic secondary amines. 5-Chloro-1,2,3,3-tetramethyl-2-azabicyclo [2,2,2] octane (cis/trans mixture) was isolated as by-product of the reaction. A number of urethanes showed antiarrhythmic activity in guinea pigs and mice, as well as surface anesthesia in rabbits and infiltration anesthesia in mice, superior or similar to lidocaine. The circulatory, cardiac and respiratory effects in dogs and hens are also described.

Anesthetics, Local↗
PubMed2002

Efficient and stereoselective synthesis of bicyclo[3.2.1]octan-8-ones: synthesis and palladium-catalyzed isomerization of functionalized 2-vinyl-2,3,3a,4,5,6-hexahydro-2,3-benzofurans.

A new C,O-cyclodialkylation of dilithiated cyclic beta-keto esters and beta-keto sulfones with 1,4-dibromo-2-butene is reported which results in regio- and diastereoselective formation of 2-vinyl-2,3,3a,4,5,6-hexahydro-2,3-benzofurans. The products could be efficiently transformed into functionalized bicyclo[3.2.1]octan-8-ones by a palladium-catalyzed rearrangement reaction. In case of sulfone derivatives, this rearrangement proceeds with high stereospecifity to give exclusively the endo-configured diastereomers. The bicyclo[3.2.1]octane skeleton is present in a large number of pharmacologically important natural products.

Benzofurans↗
PubMed1985

Hepatotoxicity in albino rats exposed to n-octane and n-nonane.

Effects of n-octane and n-nonane (1 ml per kg body weight daily) on hepatic and serum enzymes, which reflect abnormal liver function and concentration of lipid and nucleic acid (serum and liver), were studied after 2 and 7 days intraperitoneal administration to albino rats. Decreased activities of serum acetylcholine esterase and carboxyl esterase were observed, together with an increase in FDP aldolase activity. Significant decrease in the concentration of albumin, total protein, and total and esterified cholesterol in serum have been noted after n-octane and n-nonane administration for 7 days. Also, free cholesterol content of liver was elevated significantly after solvents exposure.

Alkanes↗
PubMed1986

Mechanism of anesthesia: the potency of four derivatives of octane corresponds to their hydrogen bonding capacity.

The anesthetic potency of four derivatives of n-octane was measured by tadpole righting reflex and expressed as effective millimolar concentration of drug in membrane, EDM50. Potency diminished (ED50 increased) in this order: 1-octanol, EDM50 = 5.5; 1-(2-methoxyethoxy)octane, EDM50 = 28; 1-methoxyoctane, EDM50 = 61; and 1-chlorooctane, EDM50 greater than 100. Since the aliphatic chain length was kept constant it is concluded that the differences in anesthetic potency are a consequence of the differences in head group structure. This result is predicted by a theory (Lipids 17, 1001-1003 [1982]) which holds that anesthesia is the result of a drug-induced restructuring of the hydrogen belts, those strata of the membrane that contain the hydrogen bond receiving and donating CO and OH groups of the membrane lipids and the adjoining proteins. The Meyer-Overton rule for anesthetics should be modified: chemicals induce anesthesia at equimolar in-membrane concentration provided their hydrogen-bonding parts are identical.

Anesthesia↗
PubMed1982

Effect of n-octane and n-nonane administration on alkaline phosphatase activity in tissues of female rats.

Studies on alkaline phosphatase were conducted in albino rats exposed to n-octane or n-nonane for 2 and 7 days; there was an increase in alkaline phosphatase activity of liver, spleen and bone marrow. Increase in spleen alkaline phosphatase activity persisted up to 42 days after single dose of n-octane or n-nonane. Pretreatment with protein synthesis inhibitors, cycloheximide or ethionine removed this observed increase of alkaline phosphatase activity in liver and spleen.

Alkaline Phosphatase↗
PubMed2005

3-Ethyl-2,7-dimethyl octane, a testosterone dependent unique urinary sex pheromone in male mouse (Mus musculus).

A previous investigation revealed that urine from normal male mice contained five unique volatile constituents; namely: 3-cyclohexene-1-methanol (I); 3-amino triazole (II); 4-ethyl phenol (III); 3-ethyl-2,7-dimethyl octane (IV); 1-iodoundecane (V). The present study was designed to find out whether the production of these male specific urinary compounds was androgen-dependent. Urine of castrated and castrated plus testosterone-treated male mice was analyzed using gas chromatography linked mass spectrometry (GC-MS). Even though castrated male urine contained 10 detectable compounds, the five male specific compounds present in intact males were absent in castrated male mice urine. Only 3-ethyl-2,7-dimethyl octane (IV) reappeared following testosterone treatment into castrated males. Our earlier bioassay revealed that this compound was involved in attracting females. The present study concluded that this compound was a male specific volatile cue that acted as a releaser pheromone and its production was under the control of androgen.

Animals↗
PubMed2006

Synthesis of dopamine transporter selective 3-diarylmethoxymethyl-8-arylalkyl-8-azabicyclo[3.2.1]octane derivatives.

A series of diarylmethoxymethyltropane-GBR hybrid analogues with all three possible stereochemical orientations at C3 were synthesized and evaluated at dopamine and serotonin transporters. The 3alpha derivatives were found to be the most potent compounds with the 3alpha-di(4-fluorophenyl)methoxymethyl-8-(3-phenylpropyl)-8-azabicyclo[3.2.1]octane 15b (Ki = 5 nM) being the most potent compound of the series. The corresponding 3-di(4-fluorophenyl)-methoxymethyl-8-(3-phenylpropyl)-8-azabicyclo[3.2.1]oct-2-ene 12b (Ki = 12 nM) was slightly less potent than the 3alpha-analogue, while the 3beta-di(4-fluorophenyl)methoxymethyl-8-(3-phenylpropyl)-8-azabicyclo[3.2.1]octane 23b (Ki = 78 nM) exhibited only modest affinity for the dopamine transporter. Only the 3alpha-analogue 15b (SERT/DAT = 48) exhibited higher SERT/DAT selectivity than GBR 12909. These results indicate that the dopamine transporter can tolerate some variability in proximity of the benzhydryl ether to the basic nitrogen atom of the tropane without loss in potency. In addition, the structure-activity data for these tropane-GBR 12909 hybrid analogues support previous findings that the stereochemical and conformational effects imparted by unsaturation at C3 are important for dopamine transporter selectivity over the serotonin transporter.

Bridged Bicyclo Compounds, Heterocyclic↗
PubMed2004

Recovery of dodecane, octane and toluene spills in sandpacks using ethanol.

This paper is an extension of the work of Grubb et al. on the recovery of lighter-than-water non aqueous phase liquids (LNAPLs) from sandpacks. Dodecane, toluene and octane (500 mL each) were used to simulate fresh and weathered petroleum spills. The ethanol flooding experiments evaluated the feasibility of recovering the LNAPLs from unconfined uniform sandpacks in a quasi two-dimensional apparatus. A combined pure ethanol and 50/50 (vol.%) ethanol-water blend flooding strategy successfully mobilized and recovered the simulated large-volume LNAPL spills (10x greater than previous studies). At flow rates < 7 m per day, the toluene and octane recoveries were approximately 84.9 and 88.1%, respectively, which are considered impressive as no optimization was even attempted.

Alkanes↗