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PubMed2004

Monitoring the TiO2-photocatalyzed destruction of aqueous environmental contaminants at parts-per-trillion levels using membrane introduction mass spectrometry (MIMS).

Membrane introduction mass spectrometry (MIMS) was used to directly monitor the TiO2/UV-photocatalyzed destruction of acetophenone, toluene, and chloroform in H2O at ppm to pptr concentrations. The instrument response time was sufficiently rapid for these environmental contaminants (1-6min) that "real-time" monitoring of their degradation was possible. This method was used to follow the loss of toluene at pptr levels and the concomitant formation of one of its primary photo-oxidation intermediates, methylphenol. These results illustrate the potential use of MIMS as a sensitive on-line measurement technique for monitoring photocatalytic destruction of trace organic contaminants in water at environmentally relevant levels.

Acetophenones↗
PubMed1989

Studies of error-prone DNA repair in Escherichia coli K-12 and Ames Salmonella typhimurium strains using a model alkylating agent.

4-Acetoxy-3-acetoxymethyl acetophenone (AAMAP) is mutagenic in Ames Salmonella typhimurium tester strains TA100 and TA98, which carry plasmid pKM101, but not in the isogenic plasmid-less strains TA1535 and TA1538. Similarly, no AAMAP-induced reversion of the his-4 allele is detectable in Escherichia coli K-12 umuC strains in the absence of the plasmid, even when the strains are treated with ethylene-diaminetetraacetate to increase permeability, or when the uvrB allele is introduced to increase error-prone DNA repair. AAMAP is, however, mutagenic in umuC+ strains or in umuC strains in which plasmid pKM101 has been introduced, suggesting that the plasmid-encoded MucAB or the chromosomally determined UmuDC proteins are required for mutagenesis. Mutation frequencies are higher in E. coli umuC (pKM101) strains, which resemble Ames tester strains of S. typhimurium, than in E. coli umuC+ or even umuC+ (pKM101) strains. Therefore, providing that the recommended pKM101-containing tester strains are used, the apparent absence of Umu-like protein activity in S. typhimurium may actually increase the sensitivity of the Ames test for the detection of mutagens that require error-prone DNA repair for activity.

Acetophenones↗
PubMed1993

The relation between stimulus and response in olfactory receptor cells of the tiger salamander.

1. Olfactory receptor cells were isolated from the adult tiger salamander Ambystoma tigrinum and the current in response to odorant stimuli was measured with the whole-cell voltage-clamp technique while odorants at known concentrations were rapidly applied for controlled exposure times. 2. Three odorants, cineole, isoamyl acetate and acetophenone, were first applied at 5 x 10(-4) M. Out of forty-nine cells tested, 53% responded to one odorant only, 22% to two odorants and 25% to all three odorants. 3. The amplitude of the current in response to a given odorant concentration was found to be dependent on the duration of the odorant stimulus and reached a saturating peak value at 1.2 s of stimulus duration. 4. The current measured at the peak of the response for odorant steps of 1.2 s as a function of odorant concentration was well described by the Hill equation for the three odorants with Hill coefficients higher than 1 and K1/2 (odorant concentration needed to activate half the maximal current) ranging from 3 x 10(-6) to 9 x 10(-5) M. 5. It is concluded that olfactory receptor cells are broadly tuned and have a low apparent affinity for odorants, integrate stimulus information over time, and have a narrow dynamic range.

Acetophenones↗
PubMed1973

Inhibition of cathepsin D-type proteinase of macrophages by pepstatin, a specific pepsin inhibitor, and other substances.

The macrophage is the main cell participating in chronic inflammation. It contains an acid-acting, cathepsin D-type proteinase with the specificity of pepsin, which may release mediators of the inflammatory process. To find new pharmaceutical inhibitors of this proteinase, we tested a variety of chemical compounds in vitro. For this survey, the possible inhibitor (at a concentration of 0.4 mg/ml) was assayed with partially purified cathepsin D-type proteinase from beef lung (a macrophage-rich tissue) and hemoglobin as the substrate. Diazophenylbutanone, three acetophenones, two barbiturates, a gold salt, a copper chelate of a substituted nicotinic acid, a hexapeptide containing a d-amino acid, and Pepstatin inhibited this enzyme; over 200 other potential inhibitors did not. By far the most active and specific inhibitor found to date is Pepstatin, a pentapeptide with two gamma-NH linkages, two beta-OH groups, and five branched aliphatic side chains. Banyu Pharmaceutical Co., Tokyo, Japan, produces this nontoxic compound for the treatment of peptic ulcers. In vitro, as little as 4 ng of Pepstatin inhibits the acid-acting cathepsin D-type proteinase purified from beef and rabbit lung as well as the similar proteinase of rabbit peritoneal and pulmonary macrophages.

Acetophenones↗
PubMed1996

Initial reactions in anaerobic ethylbenzene oxidation by a denitrifying bacterium, strain EB1.

Initial reactions in anaerobic oxidation of ethylbenzene were investigated in a denitrifying bacterium, strain EB1. Cells of strain EB1 mineralized ethylbenzene to CO2 under denitrifying conditions, as demonstrated by conversion of 69% of [14C]ethylbenzene to 14CO2. In anaerobic suspensions of strain EB1 cells metabolizing ethylbenzene, the transient formation and consumption of 1-phenylethanol, acetophenone, and an as yet unidentified compound were observed. On the basis of growth experiments and spectroscopic data, the unknown compound is proposed to be benzoyl acetate. Cell suspension experiments using H2(18)O demonstrated that the hydroxyl group of the first product of anoxic ethylbenzene oxidation, 1-phenylethanol, is derived from water. A tentative pathway for anaerobic ethylbenzene mineralization by strain EB1 is proposed.

Acetophenones↗
PubMed2000

Effect of the NADPH oxidase inhibitor apocynin on ischemia-reperfusion lung injury.

Apocynin (4-hydroxy-3-methoxy-acetophenone) inhibits NADPH oxidase in activated polymorphonuclear (PMN) leukocytes, preventing the generation of reactive oxygen species. To determine if apocynin attenuates ischemia-reperfusion lung injury, we examined the effects of apocynin (0.03, 0.3, and 3 mM) in isolated in situ sheep lungs. In diluent-treated lungs, reperfusion with blood (180 min) after 30 min of ischemia (ventilation 28% O(2), 5% CO(2)) caused leukocyte sequestration in the lung and increased vascular permeability [reflection coefficient for albumin (sigma(alb)) 0.47 +/- 0.10, filtration coefficient (K(f)) 0.14 +/- 0.03 g. min(-1). mmHg(-1). 100 g(-1)] compared with nonreperfused lungs (sigma(alb) 0.77 +/- 0. 03, K(f) 0.03 +/- 0.01 g. min(-1). mmHg(-1). 100 g(-1); P < 0.05). Apocynin attenuated the increased protein permeability at 0.3 and 3 mM (sigma(alb) 0.69 +/- 0.05 and 0.91 +/- 0.03, respectively, P < 0. 05); K(f) was decreased by 3 mM apocynin (0.05 +/- 0.01 g. min(-1). mmHg(-1). 100 g(-1), P < 0.05). Diphenyleneiodonium (DPI, 5 microM), a structurally unrelated inhibitor of NADPH oxidase, worsened injury (K(f) 0.32 +/- 0.07 g. min(-1). mmHg(-1). 100 g(-1), P < 0.05). Neither apocynin nor DPI affected leukocyte sequestration. Apocynin and DPI inhibited whole blood chemiluminescence and isolated PMN leukocyte-induced resazurin reduction, confirming NADPH oxidase inhibition. Apocynin inhibited pulmonary artery hypertension and perfusate concentrations of cyclooxygenase metabolites, including thromboxane B(2). The cyclooxygenase inhibitor indomethacin had no effect on the increased vascular permeability, suggesting that cyclooxygenase inhibition was not the explanation for the apocynin results. Apocynin prevented ischemia-reperfusion lung injury, but the mechanism of protection remains unclear.

Acetophenones↗
PubMed2004

In vitro estrogenicity of resin composites.

Previously, we have reported that sealants incorporating bisphenol A dimethacrylate showed estrogenicity by a reporter gene assay. This study tested the hypothesis that commercial composites, which contain various monomers and additives, exhibit estrogenic activity in vitro. The estrogenic activities of eluates obtained from 24 composites and 18 chemicals identified from the composites tested were examined with the use of the reporter gene assay. Among the 24 composites, 6 products were estrogenic, and among the 18 constituents, 1 photostabilizer, 2-hydroxy-4-methoxy-benzophenone (HMBP), 1 photoinitiator, 2,2-dimethoxy-2-phenyl-acetophenone (DMPA), and 1 inhibitor, 2,6-di-tert-butyl-p-cresol (BHT) had significant estrogenic activity. The concentration of HMBP in 4 estrogenic eluates was greater than the minimum concentration required for estrogenicity, and DMPA was found at a higher level than the minimum estrogenic concentration in the remaining 2 estrogenic specimens. These results suggest that the observed estrogenic activity of 6 composites is associated with the elution of either HMBP or DMPA.

Acetophenones↗
PubMed1998

Antidiabetic principles of natural medicines. II. Aldose reductase and alpha-glucosidase inhibitors from Brazilian natural medicine, the leaves of Myrcia multiflora DC. (Myrtaceae): structures of myrciacitrins I and II and myrciaphenones A and B.

The methanolic extract and ethyl acetate-soluble portion from a Brazilian natural medicine, the leaves of Myrcia multiflora DC., which has been used as a specific medicine against diabetes, were found to show inhibitory activities on aldose reductase and alpha-glucosidase and on the increase of serum glucose level in sucrose-loaded rats and in alloxan-induced diabetic mice. From the ethyl acetate-soluble portion, new flavanone glucosides, myrciacitrins I and II, and new acetophenone glucosides, myrciaphenones A and B, were isolated together with several known compounds such as five flavonol glycosides, myricitrin, mearnsitrin, quercitrin, desmanthin-1, and guaijaverin. The structures of new compounds were determined on the basis of physicochemical and chemical evidence. The principal components of this natural medicine including new glucosides, myrciacitrin I and myrciaphenone B, were found to show potent inhibitory activities on aldose reductase and alpha-glucosidase.

Acetophenones↗
PubMed1975

Inhibitors of hepatic mixed function oxidases. I. The metabolism of 2,6-dihydroxy-,2-hydroxy-6-methoxy- and 2,6-dimethoxyacetophenones.

1. 2,6-Dihydroxyacetophenone, its mono- and di-methyl ethers are inhibitors of hepatic mixed function oxidases. The dimethyl ether is a competitive inhibitor of aminopyrine demethylase with the others displaying mixed kinetics. The metabolism of all three ketones has been studied. 2. 2,6-Dihydroxyacetophenone is excreted unchanged and as conjugates. 3. 2-Hydroxy-6-methoxyacetophenone is largely excreted unchanged and conjugated but small amounts of the 3- and 5-hydroxylated derivatives are formed. 4. 2,6-Dimethoxyacetophenone is demethylated to 2-hydroxy-6-methoxy-acetophenone. In addition 3-hydroxy-2,5-dimethoxyacetophenone and 2,3-dihydroxy-6-methoxyacetophenone were identified as metabolites. 5. Quantitative data on the excretion of metabolites were obtained with 14C-labelled ketones.

Acetophenones↗
PubMed1999

Photopolymerized 2-hydroxyethylmethacrylate as a mounting medium preserving immunocytochemical reaction and nuclear counterstain.

Immunocytochemical or cytoenzymological techniques often make use of coupling reactions between a substituted naphtol and a diazonium salt. A positive reaction results in an azo dye precipitate. Unfortunately, this precipitate is easily soluble in alcohols and organic solvents. Thus, usual mounting media are not usable and permanent preparations cannot be obtained. A stable mounting medium such as Apathy's syrup can be used, but nuclear counterstaining disappears in a few days. We tested the hydrophilic monomer 2-hydroxyethylmethacrylate, containing various photopolymerizing agents, as a permanent mounting medium. 2-2 Dimethoxy 2-phenyl acetophenone proved to be the most useful photopolymerizer. The cytocentrifugation slides must be dried before mounting to avoid recrystallization artifacts. The azo dye precipitate and nuclear counterstaining can be preserved perfectly long-term. The cost of these media is very low.

Acetophenones↗
PubMed1976

Species-specific hypoglycemic activity of triphenylphosphoranylideneacetophenones.

The species-specific hypoglycemic activity of two 2-triphenylphosphoranylideneacetophenones is described. 2-Triphenylphosphoranylideneacetophenone (SK&F 45359) and 2-triphenylphosphoranylidene-m-trifluoromethyl-acetophenone (SK&F 62775) were hypoglycemic in various rat models, but failed to exhibit hypoglycemic activity in other species.

Acetophenones↗
PubMed2002

Odorant receptor expression defines functional units in the mouse olfactory system.

Odorant receptors (ORs) mediate the interaction of odorous compounds with olfactory sensory neurons (OSNs) and influence the guidance of OSN axons to synaptic targets in the olfactory bulb (OB). OSNs expressing the same OR send convergent axonal projections to defined glomeruli in the OB and are thought to share the same odorant response properties. This expectation of functional similarity has not been tested experimentally, because it has not been possible to determine reproducibly the response properties of OSNs that express defined ORs. Here, we applied calcium imaging to characterize the odorant response properties of single neurons from gene-targeted mice in which the green fluorescent protein is coexpressed with a particular OR. We show that the odorants acetophenone and benzaldehyde are agonists for the M71 OR and that M71-expressing neurons are functionally similar in their response properties across concentration. Replacing the M71 coding sequence with that of the rat I7 OR changes the stimulus response profiles of this genetically defined OSN population and concomitantly results in the formation of novel glomeruli in the OB. We further show that the mouse I7 OR imparts a particular response profile to OSNs regardless of the epithelial zone of expression. Our data provide evidence that ORs determine both odorant specificity and axonal convergence and thus direct functionally similar afferents to form particular glomeruli. They confirm and extend the notion that OR expression provides a molecular basis for the formation and arrangement of glomerular functional units.

Acetophenones↗
PubMedDate not supplied

Further studies of metyrapone effects upon anilide hydroxylation.

The enhancing effect of metyrapone upon the p-hydroxylation of acetanilide has been confirmed with the use of a new gas-chromatographic method for the determination of acetaminophen. This effect has been shown not to be due to inhibition of hydrolysis of acetaminophen or interference with its determination, or to preferential formation of other phenolic metabolites. This effect of metyrapone is remarkably substrate-specific: phenol formation from the homologues of acetanilide, formanilide and propionanilide, and that from the sulfonamide analog of acetanilide, methanesulfonanilide, is inhibited by metyrapone over the concentration range in which acetanilide hydroxylation is enhanced. The same substrate specificity was observed when the modifier was acetophenone. alpha,alpha'-Dipyridyl, however, enhances phenol formation from all three carbonacylanilides, but does not affect that from methanesulfonanilide.

2,2'-Dipyridyl↗
PubMed1992

Metabolic activation of phenols by stimulated neutrophils: a concept for a selective type of anti-inflammatory drug.

Apocynin (4-hydroxy-3-methoxy-acetophenone) is a potent and selective inhibitor of neutrophil oxyradical production. The mechanism of action involves metabolic activation in a (myelo)-peroxidase-dependent reaction. The reaction product(s) prevent(s) the assembly of the superoxide anion-generating NADPH:O2 oxidoreductase by conjugation to essential thiol groups. Different neutrophil functions that are essential to their bactericidal activity, however, remain intact. When administered orally a potent anti-inflammatory activity was found in rats with experimentally induced local or systemic inflammation.

Acetophenones↗
PubMed1979

Microbiological transformations. XI. The use of immobilized Rhodotorula mucilaginosa cells to reduce some ketones.

Rhodotorula mucilaginosa cells were immobilized by polymerizing acrylamide with the addition of a cross-linked agent, a catalyst and an initiator. This gel was used for the stereospecific reduction of acetophenone and alpha-acetylnaphthalene resulting chromatographically pure alcohols with absolute configuration S. When karen-3-dion-2,5 was used as substrate, four products were obtained. Androstenolone was reduced with 30% yield. Activity of the immobilized cells could be regenerated by glucose.

Acetophenones↗
PubMed2006

[Rapid identification of compounds in cortex moutan by liquid chromatography-tandem mass spectrometry].

AIM: To analyze the chemical constituents of cortex moutan by liquid chromatography coupled with electrospray ionization mass spectrometry. METHODS: An on-line optimized HPLC-DAD/MS2 technique was employed. RESULTS: In the negative ion detection mode, 38 components such as monoterpene glucosides, galloylglucoses and acetophenones were isolated. Among them, over thirty compounds were identified, including paeonol, paeonilflorin, oxypaeoniflorin, benzoylpaeoniflorin, benzoyloxypaeoniflorin, galloylpaeoniflorin, galloyloxypaeoniflorin, mundanpioside A, C, D, E, H, etc. by the high performance liquid chromatography with diode-array detection in parallel with electrospray ionization and quadrupole-time of flight tandem mass spectrometry (HPLC-DAD/ESI-MS2). CONCLUSION: This method can be used to rapidly determine the constituents of cortex moutan.

Acetophenones↗
PubMed1988

Evaluation of some azines of aminomethylacetophenones and related quaternary ammonium compounds versus the EMT6 tumour.

Azines derived from 3-dimethylamino-1-phenyl-1-propanone hydrochloride and two ring dimethylaminomethyl-acetophenones as well as the related quaternary ammonium iodides were synthesized. In phosphate buffer ph 7.4/37 degrees C 3-dimethylamino-1-phenyl-1-propanone azine dimethoiodide (2) formed 1-phenyl-3-(3-phenyl-2-pyrazolin-1-yl)-1-propanone. In the presence of a biomimetic thiol, 2-mercaptoethanol, compound 2 gave a bis S-alkylated product namely 3-(2-hydroxyethylthio)-1-phenyl-1-propanone azine. New products were not observed when two quaternary ammonium compounds derived from ring aminomethylacetophenone azines were examined under similar conditions. Six derivatives had moderate activity against the EMT6 tumour in vitro at concentrations of 250-500 mumol.1(-1) and greatest potency was noted with the ring dimethylaminomethylacetophenone azines and related quaternary ammonium compounds at these concentrations.

Acetophenones↗
PubMedDate not supplied

[Oxidation of alpha-methylstyrene by Pseudomonas cultures].

The work was aimed at studying alpha-methylstyrene oxidation by three active Pseudomonas cultures. P. acidovorans 9 oxidized alpha-methylstyrene only to acetophenone whereas two P. aeruginosa cultures assimilated the compound entirely. Analysis of the intermediate products and enzymes catalyzing the aromatic ring cleavage suggests that these strains oxidize alpha-methylstyrene via a new unknown pathway.

Acetophenones↗