Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dimethylamines”

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 667 records · Page 37Linked to original sources
PubMed2002

New electron-deficient chiral phosphines: (4R,5R)-1,3-bis(trifluoromethanesulfonyl)perhydro-1,3,2-benzodiazaphosphol-2-yl] substituted amines.

Three chiral electron-deficient phosphine ligands, [(4R,15R)-,3-bis(trifluoromethanesulfonyl)perhydro-1,3,2-benzodiazaphosphol-2-yl]diethylamine, C(12)H(20)F(6)N(3)O(4)PS(2), (IIIa), [(4R,5R)-1,3-bis(trifluoromethanesulfonyl)perhydro-1,3,2-benzodiazaphosphol-2-yl]dimethylamine, C(10)H(16)F(6)N(3)O(4)PS(2), (IIIb), and bis[(4R,5R)-1,3-bis(trifluoromethanesulfonyl)perhydro-1,3,2-benzodiazaphosphol-2-yl]methylamine, (IV), as the chloroform solvate, C(17)H(23)F(12)N(5)O(8)P(2)S(4).0.98CHCl(3), have been prepared from (1R,2R)-N,N'-bis(trifluoromethanesulfonyl)-1,2-cyclohexanediamine and diethyl phosphoramidous dichloride, dimethyl phosphoramidous dichloride or methyl imidodiphosphorus tetrachloride. The pi-acceptor abilities of these new types of ligands have been evaluated by X-ray determination of the P-N bond lengths; it has been found that the most promising ligand is the bis(phosphine) (IV).

Journal Article↗
PubMed1999

Hydrogen bonding and C-H...O interactions in bis(8-dimethylamino-1-dimethylammonionaphthalene) [(DMANH+)2] 4,8-dicarboxynaphthalene-1,5-dicarboxylate dihydrate.

The title substance, 2C14H19N2+.C14H6O8(2-).2H2O, crystallized in the centrosymmetric space group P1 with one monopositive dimethylamine-dimethylammonio cation, half of a dinegative acid anion and one water molecule in the asymmetric unit, with the anion located on a center of symmetry. There are four intermolecular hydrogen bonds, of which three have Odonor...Oacceptor distances of 2.577 (1), 2.946 (2) and 2.764 (2) A, while the fourth has an Ndonor...Oacceptor distance of 3.154 (2) A. There is a single intramolecular hydrogen bond, in which the Ndonor...Nacceptor distance is 2.620 (2) A. In each case, the O, or N, and H atoms are ordered. The Ndonor-H distance in the intramolecular hydrogen bond, 1.06 (1) A, is among the shortest seen in this cation at room temperature. Moreover, the antiplanar orientation of the H atom in the hydrogen bond between acid anions is noteworthy. There are, in addition, 12 significant intermolecular C-H...O interactions. In these, the C...O distances range from 3.229 (2)-3.671 (2) A, while the C-H...O angles range from 121-165 degrees for the fixed H atoms involved. A three-dimensional network of hydrogen-bonding interactions is generated.

1-Naphthylamine↗
PubMed2001

Amphiphiles modify the properties of detergent solutions used in crystallization of membrane proteins.

The effect of the amphiphile heptanetriol on the properties of solutions containing several detergents commonly used for crystallization of membrane proteins was characterized. The critical micelle concentration was found to be relatively unchanged by the presence of the amphiphile. In contrast, the addition of heptanetriol to solutions containing both detergent and polyethylene glycol exhibited significant shifts in the clouding behavior, with the largest shifts being for lauryl dimethylamine oxide. These results suggest that conditions favorable for crystallization of integral membrane proteins can be inferred from the properties of the detergents and amphiphiles.

Crystallization↗
PubMed2006

Crystallization and preliminary X-ray crystallographic analysis of the Escherichia coli outer membrane cobalamin transporter BtuB in complex with the carboxy-terminal domain of TonB.

The energy-dependent uptake of organometallic compounds and other micronutrients across the outer membranes of Gram-negative bacteria is carried out by outer membrane active-transport proteins that utilize the proton-motive force of the inner membrane via coupling to the TonB protein. The Escherichia coli outer membrane cobalamin transporter BtuB and a carboxy-terminal domain of the TonB protein, residues 147-239 of the wild-type protein, were expressed and purified individually. A complex of BtuB and TonB(147-239) was formed in the presence of the substrate cyanocobalamin (CN-Cbl; vitamin B12) and calcium and was crystallized. BtuB was purified in the detergent LDAO (n-dodecyl-N,N-dimethylamine-N-oxide) and the complex was formed in a detergent mixture of LDAO and C8E4 (tetraethylene glycol monooctylether). Crystals were obtained by sitting-drop vapor diffusion, with the reservoir containing 30%(v/v) polyethylene glycol (PEG 300) and 100 mM sodium acetate pH 5.2. The crystals belong to space group P2(1)2(1)2(1) (unit-cell parameters a = 74.3, b = 82.4, c = 122.6 angstroms). The asymmetric unit consists of a single BtuB-TonB complex. Data sets have been collected to 2.1 angstroms resolution at a synchrotron beamline (APS SER-CAT 22-ID).

Bacterial Outer Membrane Proteins↗
PubMed2006

Characterization of a Methanosarcina acetivorans mutant unable to translate UAG as pyrrolysine.

The methyltransferases initiating methanogenesis from trimethylamine, dimethylamine and monomethylamine possess a novel residue, pyrrolysine. Pyrrolysine is the 22nd amino acid, because it is encoded by a single amber (UAG) codon in methylamine methyltransferase transcripts. A dedicated tRNA(CUA) for pyrrolysine, tRNA(Pyl), is charged by a pyrrolysyl-tRNA synthetase with pyrrolysine. As the first step towards the genetic analysis of UAG translation as pyrrolysine, a 761 base-pair genomic segment in Methanosarcina acetivorans containing the pylT gene (encoding tRNA(Pyl)) was deleted and replaced by a puromycin resistance cassette. The DeltappylT mutant lacks detectable tRNA(Pyl), but grows as wild-type on methanol or acetate. Unlike wild-type, the DeltappylT strain cannot grow on any methylamine, nor use monomethylamine as sole nitrogen source. Wild-type cells, but not DeltappylT, have monomethylamine methyltransferase activity during growth on methanol. Immunoblot analysis indicated monomethylamine methyltransferase was absent in DeltappylT. The phenotype of DeltappylT reveals the deficiency in methylamine metabolism expected of a Methanosarcina species unable to decode UAG codons as pyrrolysine, but also that loss of pylT does not compromise growth on other substrates. These results indicate that in-depth genetic analysis of UAG translation as pyrrolysine is feasible, as deletion of pylT is conditionally lethal depending on growth substrate.

Amino Acyl-tRNA Synthetases↗
PubMed1989

Interaction of non-classical detergents with the mitochondrial porin. A new purification procedure and characterization of the pore-forming unit.

The effect of different families of detergents on the solubilization and purification of the pore-forming protein (porin) of the mitochondrial outer membrane of bovine heart was investigated in detail. With Tritons, dimethylamine oxides and zwittergents, porin solubilization with respect to total mitochondrial membrane protein was more efficient with the more hydrophobic members of each series. With most detergents the protein eluted as protein-detergent micelles in the void volume of hydroxyapatite/celite columns. In contrast, the protein was bound to the column material and was eluted after the addition of salt to the elution buffer when the detergents octylglucoside, zwittergent Z-314 and lauryl(dimethyl)-amine oxide were used. The protein purified in the presence of the latter detergent had a higher pore-forming activity in lipid bilayer membranes compared to porin isolated in the presence of Triton X-100. The binding of porin to the hydroxyapatite/celite column was used to study the lipid content of the active pore-forming complex. The analysis revealed that the complex contained no phospholipid but rather five molecules of cholesterol/polypeptide chain.

Animals↗
PubMed1981

Synaptosomes from rat brain: morphology, compartmentation, and transmembrane pH and electrical gradients.

Morphological studies of synaptosomes isolated from rat brains show that approximately 68% of the synaptosomes in these preparations contain synaptic vesicles (range, 62--72.5%). Approximately 30% of the synaptosomes contain mitochondria, and only less than 20% of the total mitochondria in good preparations are free and not enclosed in synaptic structures. The mitochondrial volume percent calculated on the basis of the measured cytochrome c content is 5% for synaptosomes isolated from anesthetized animals and 11% for synaptosomes isolated from unanesthetized animals. These numbers bracket the value of 8.7% obtained from electron micrographs. The volume percent of intrasynaptic vesicles is 1.5% as calculated from electron micrographs. The pH gradient between the extracellular pH and the mean intracellular pH is --0.45, as measured by equilibrium distributions of methylamine and dimethylamine, and --0.05, as determined by equilibrium distributions of 5,5-dimethyloxazolidine-2,4-dione and trimethylacetic acid. Analysis of these data shows that there cannot be a large pH gradient (alkaline inside) across the mitochondria, nor can the synaptic vesicle compartment be very large (less than 1.85%). Equilibrium distribution of [3H]triphenylmethylphosphonium ion in synaptosomal preparations gives a calculated apparent potential of --85 mV, in agreement with our previous value. Analysis of these data using the measured volumes of mitochondrial and intrasynaptic vesicular compartments (8.7 and 1.5%, respectively) gives a maximum possible transmitochondrial membrane potential of --59 mV.

Animals↗
PubMed1970

Some central effects in mice of compounds related to nicotine.

1. Some hydroxy-, amino-, and methoxy- phenylalkyltrimethylammonium compounds, beta-pyridylmethyl- dimethylamine and pyrrolidine, and beta-pyridylethyltrimethylammonium, were tested on avoidance learning in mice and their effects were compared with those of (-)-nicotine.2. The o- and m- hydroxybenzyl-, o-hydroxyphenethyl- and m-hydroxyphenylpropyl- trimethylammonium compounds improved performance; (-)-nicotine, in one-quarter of the dose, had similar effects. The m- and p-hydroxyphenethyl-, o-hydroxyphenylpropyl- and o- and p- aminobenzyl, and o-, m-, and p- aminophenethyl-trimethylammonium compounds impaired performance.3. (-)-Nicotine and m-hydroxyphenylpropyltrimethylammonium appeared also to enhance memory consolidating processes.4. The central actions of some of the compounds suggest that the possibility that they can penetrate into the central nervous system should not be ruled out even though they are quaternary salts.5. No correlation was found between the effects of the compounds on avoidance learning and on the frog rectus muscle. Though the differences may be due to differences in access to the central nervous system, it is also possible that the receptors associated with learning processes are different from those in the frog rectus and possibly more specialized.

Animals↗
PubMed1988

The affinity of some acetylenic analogues of 4-DAMP methobromide for muscarinic receptors in guinea-pig ileum and atria.

1. The replacement of 4-hydroxy-N-methyl piperidine (HO NMe) in 4-diphenylacetoxy-N-methyl piperidine (4-DAMP) metho-bromide by 4-hydroxy-but-2-ynylamines (HOCH2C=CCH2NR2) reduces the affinity for muscarine-sensitive acetylcholine receptors in guinea-pig ileum and atria. It does not abolish selectivity. The tertiary amines are more active and more selective than the corresponding quaternary salts. 2. Analogous derivatives of 4-hydroxy-but-2-ynylamines which lack the ester group (i.e. substituted 4-hydroxymethyl-propynyl amines) are less active and less selective. The quaternary compounds are more active than the tertiary bases. 3. The diphenylcarbamyl ester of 4-hydroxy-N-methylpiperidine methobromide has less than one-thousandth of the activity of the diphenylacetyl ester (4-DAMP methobromide) and is not selective. 4. Although 4-diphenylacetoxy-butynyl dimethylamine is only about one-hundredth as active as 4-DAMP methobromide it appears to have comparable selectivity. It is an interesting compound because it is a tertiary amine and should cross membranes.

Animals↗
PubMed1976

In vitro polarographic studies of rat brain oxygen uptake in simulated uraemia and hepatic coma.

A polarographic technique has been used to study the oxygen uptake of rat brain homogenates incubated with metabolites known to accumulate in uraemia and hepatic coma. In general, results with individual metabolites were in agreement with those previously obtained with brain slices using the Warburg technique. Inhibition was induced at higher concentrations with urea, creatine, indoxysulphate, guanidine, dimethylamine hydrochloride, ammonium chloride, taurocholate, glycodeoxycholate, sodium deoxycholate, skalote and indole. Serum and ultrafiltrate from drowsy uraemic patients also caused inhibition, and this was reversed by renal dialysis. Similarly serum and ultrafiltrate from patients in hepatic coma inhibited oxygen uptake but in this instance reversal of the inhibition was not demonstrated following exchange blood transfusion to the patients.

Adenosine Diphosphate↗
PubMed1987

Contact allergy to cosmetics: causative ingredients.

Of 1781 patients with contact dermatitis seen during a period of 6 years (1981-1986), 75 (4.2%) had allergy to cosmetic products. The face was most frequently affected. In many cases, the dermatitis was limited to the eyelids (18.7%) or the face (40.0%). Skin care products (moisturizing and cleansing cream/lotion/milk) accounted for more than half (52.3%), followed by nail cosmetics (8.0%), shaving preparations (8.0%) and deodorants (6.8%). The ingredients most often responsible were fragrances (45.1%), followed by the preservative Kathon CG (11.0%) and the emulsifier oleamidopropyl dimethylamine (9.8%). In 14 patients (18.7%), patch tests with the responsible cosmetic product were negative. In them, the diagnosis was made by use tests and/or repeated open application tests. Compulsory declaration of ingredients on cosmetic product labels in the EEC, analagous to the USA situation, would be of great benefit both to patients and to physicians.

Adolescent↗
PubMed1994

Identification of causative chemicals of allergic contact dermatitis using a combination of patch testing in patients and chemical analysis. Application to cases from rubber gloves.

5 cases of allergic contact dermatitis from rubber gloves were investigated by our recommended procedures using a combination of patch testing in patients and chemical analysis of causative rubber products by gas chromatography (GC) and high-performance liquid chromatography (HPLC). We previously confirmed that zinc ethylphenyldithiocarbamate (ZEPC), a dithiocarbamae-type accelerator (DTC), was causative in a case of allergic contact dermatitis from rubber work gloves. Subsequently, we have clarified that DTCs such as zinc dimethyldithiocarbamate (ZDMC), zinc diethyldithiocarbamate (ZDEC) and zinc dibutyldithiocarbamate (ZDBC) and amines such as dimethylamine (DMA), diethylamine (DEA) and piperidine (PIP) were also causative in cases from surgical rubber gloves. Thus, our investigative studies revealed that, although thiurams have been taken much more notice of as allergenic compounds than their corresponding DTCs and amines, not only DTCs such as ZDMC, ZDEC, ZDBC and ZEPC, but also amines such as DMA, DEA and PIP were noteworthy causative candidates of allergic contact dermatitis from rubber gloves.

Adult↗
PubMed2006

The aetiology of eyelid dermatitis: a 10-year retrospective analysis.

Few studies have examined the aetiology of eyelid dermatitis across broad demographics. The objectives of this study were (i) to compare the diagnoses of patients with isolated eyelid dermatitis to the diagnoses of patients with additional sites of involvement and (ii) to determine the relevant allergens among patients with allergic eyelid dermatitis. A retrospective analysis of 1215 patients patch tested over 10 years was conducted in this study. Compared to patients without eyelid dermatitis, patients with this entity were more often female. Of the 105 patients with eyelid dermatitis, 43.8% had allergic contact dermatitis (ACD), 36.2% seborrhoeic dermatitis, 11.4% other dermatitis/dermatoses, 7.6% irritant contact dermatitis, 3.8% psoriasis, and 2.9% atopic eczema. With isolated eyelid dermatitis, seborrhoeic dermatitis was the most frequent diagnosis (46.3%) followed by ACD (35.2%). Allergens commonly causing allergic eyelid dermatitis consisted of fragrances, metals, neomycin, oleamidopropyl dimethylamine, tosylamide formaldehyde resin, benzalkonium chloride, and other preservatives. When evaluated according to sites of involvement, seborrhoeic dermatitis was diagnosed most often in patients with isolated eyelid dermatitis, but when dermatitis was distributed to facial or other sites, ACD was the most frequent diagnosis. A majority of the causative allergens for eyelid dermatitis are not present on the Food and Drug Administration-approved panels available in the USA.

Adolescent↗
PubMed1988

Effect of allopurinol on oxidant stress and hepatic function following ischemia and reperfusion in the rat.

Reactive oxygen species generated by xanthine oxidase during reperfusion of ischemic liver might in part be responsible for ischemic organ injury. Therefore, the effect of allopurinol, an inhibitor of xanthine oxidase, on the oxidant stress associated with reperfusion and on hepatic function 24 h after ischemia was assessed in a model of partial hepatic ischemia in rats. The increase in circulating glutathione disulfide (GSSG) was used as an index of oxidant stress. Hepatic function was assessed using a breath test to quantitative the demethylation of aminopyrine in vivo. In control animals the plasma concentration of GSSG 1 h after onset of reperfusion increased from 0.9 mumol/l in sham-operated controls to 4.2, 5.5, and 8.0 mumol/l following 45, 90 and 120 min of ischemia, respectively. The percent of the administered dose of (dimethylamine-14C)-aminopyrine appearing in breath as 14CO2 was not significantly different from sham-operated controls (40.2%) 24 h after 45 min of ischemia (34.1%), but decreased progressively to 26.0% (p less than 0.05) and 20.6% (p less than 0.05) after 90 and 120 min of ischemia, respectively. Allopurinol, administered at a dose of 50 mg/kg 18 h and 1 h prior to ischemia, did not prevent the rise in plasma GSSG, did not alleviate the release of transaminases, and did not improve the demethylation of aminopyrine 24 h after ischemia, suggesting that reactive oxygen species generated by xanthine oxidase during reperfusion of ischemic liver do not contribute significantly to ischemic injury.

Allopurinol↗
PubMed1986

O-dealkylation of phenacetin in the olfactory rosette in rainbow trout (Salmo gairdneri).

Olfactory rosettes from trout (Salmo gairdneri) were found to metabolise (14C-ethyl)-phenacetin to 14CO2 in vitro. Based on wet weight, the rate of metabolism was lower than that in liver and gills. Based on protein content, the rate of metabolism was about equal to that in liver and gills. Addition of the cytochrome P-450 inhibitors metyrapone, 9-hydroxyellipticine and piperonyl butoxide significantly decreased the formation of 14CO2 from (14C-ethyl)-phenacetin in olfactory rosettes. Microautoradiography of rosettes incubated with (14C-ethyl)-phenacetin showed the presence of non-extractable metabolites in the sensory and indifferent epithelium. Addition of metyrapone decreased the binding of radioactivity in the epithelia considerably. When olfactory rosettes were incubated with (14C-dimethylamine)-aminopyrine, no formation of 14CO2 was observed. The results are concluded to indicate that cytochrome P-450 dependent enzyme activity is present in the epithelia of the trout olfactory rosette.

Aminopyrine↗
PubMed1989

The enhanced daily excretion of urinary methylamine in rats treated with semicarbazide or hydralazine may be related to the inhibition of semicarbazide-sensitive amine oxidase activities.

The effects of amine oxidase inhibitors upon the daily urinary excretion of monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA) and ammonia in the rat have been examined. Administration of hydralazine (5 mg kg-1) or semicarbazide (100 mg kg-1), drugs which irreversibly inhibit semicarbazide-sensitive amine oxidases (SSAO) but not monoamine oxidase (MAO), enhanced MMA excretion by around three- to six-fold above pretreatment levels, whereas no effect of pargyline (25 mg kg-1), a selective irreversible inhibitor of MAO was found. No apparent changes in DMA or TMA excretion in response to drug-treatment were observed. Ammonia excretion also was generally unchanged except for an apparent marked increase (approximately four-fold) over the 24 h following semicarbazide, a result which might be explained if ammonia is a degradation product of semicarbazide metabolism in the rat. With recent evidence that MMA is a substrate in-vitro for SSAO activities, results here may indicate that SSAO or related enzymes are involved in endogenous MMA turnover.

Animals↗
PubMed1996

Ionic permeability of, and divalent cation effects on, two ATP-gated cation channels (P2X receptors) expressed in mammalian cells.

1. Complementary DNAs for the ATP-gated ion channel subunits P2X1 (from human bladder) and P2X2 (from rat phaeochromocytoma (PC12) cells) were used to express the receptors in human embryonic kidney cells by stable transfection, and in Chinese hamster ovary cells by viral infection. 2. Membrane currents evoked by ATP were recorded by the whole-cell patch clamp method. The reversal potential of the current was measured with various intracellular and extracellular solutions and used to compute the relative permeability of the P2X receptor channels. 3. There was no difference between the two receptors with respect to their permeability to monovalent organic cations. The relative permeabilities (PX/PNa) were 2.3, 1.0, 1.0, 0.95, 0.72, 0.5, 0.29, 0.16, 0.04 and 0.03 for guanidinium, potassium, sodium, methylamine, caesium, dimethylamine, 2-methylethanolamine, tris(hydroxymethyl)-aminomethane, tetraethylammonium and N-methyl-D-glucamine, respectively (values for P2X2 receptor). 4. The calcium permeability of P2X1 receptors was greater than that of P2X2 receptors. Under biionic conditions (112 mM calcium outside, 154 mM sodium inside), PCa/PNa values were 3.9 and 2.2, respectively (corrected for ionic activities). 5. ATP-evoked currents in cells expressing the P2X2 receptor were strongly inhibited when the extracellular calcium concentration was increased (0.3-30 mM); the action of ATP could be restored by increasing the ATP concentration. ATP-evoked currents in cells expressing the P2X1 receptor were not inhibited by such increases in the extracellular calcium concentration.

Adenosine Triphosphate↗
PubMed2004

Serotonin1B receptors in the ventral tegmental area modulate cocaine-induced increases in nucleus accumbens dopamine levels.

Previous work has demonstrated that peripheral serotonin(1B) (5-HT(1B)) receptor agonist administration facilitates the behavioral and neurochemical effects of cocaine. This study used dual probe microdialysis to investigate whether activation of serotonin(1B) (5-HT(1B)) receptors in the ventral tegmental area (VTA) alters the ability of peripherally administered cocaine to elevate dopamine (DA) levels in the ipsilateral nucleus accumbens (NAcc) of drug-naive Wistar rats. Intra-VTA administration of the selective 5-HT(1B) agonist 1,4-dihydro-3-(1,2,3,6-tetrahydro-4-pyridinyl)-5H-pyrrolo [3,2-b]pyridin-5-one dihydrochloride (CP 93,129) by reverse dialysis produced a dose-dependent (30 and 100 microM) potentiation of cocaine-induced (10 mg/kg i.p.) increases in NAcc DA efflux and concurrent cocaine-induced decreases in VTA GABA efflux. There was no effect of either local CP 93,129 or peripheral cocaine on VTA glutamate efflux. Intra-VTA administration of the 5-HT(1A/7) receptor agonist 8-hydroxy-2-dipropylaminotetralin (8-OH-DPAT; 100 microM) did not alter cocaine-induced alterations in NAcc DA or VTA GABA, suggesting that the effects of CP 93,129 were not mediated through 5-HT(1A) receptors. Moreover, the effects of intra-VTA CP 93,129 (100 microM) on both cocaine-induced increases in NAcc DA levels and cocaine-induced decreases in VTA GABA levels were reversed by coadministration of the selective 5-HT(1B) receptor antagonist 3-[3-(dimethylamine)propyl]-4-hydroxy-N-[4-(4-pyridinyl] phenyl] benzamide dihydrochloride (GR 55562; 300 microM). In the absence of cocaine, intra-VTA CP 93,139 produced an increase in NAcc DA and decrease in VTA GABA levels. However, intra-VTA GR 55562 alone had no effect on any of our neurochemical measures. These findings indicate that activation of VTA 5-HT(1B) receptors potentiates cocaine-induced increases in NAcc DA levels by enhancing the ability of cocaine to decrease VTA GABA efflux.

Animals↗