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Results for “Benzophenones”

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At least 19 recordsLinked to original sources

PubMed1990

Benzophenone dicarboxylic acid antagonists of leukotriene B4. 1. Structure-activity relationships of the benzophenone nucleus.

A series of lipophilic benzophenone dicarboxylic acid derivatives was prepared which inhibited the binding of the potent chemotaxin leukotriene B4 to its receptor(s) on intact human neutrophils. With a radioligand-binding assay as a measure of receptor affinity, a structure-activity relationship for this series was investigated. Both acidic residues were required for receptor-binding activity. The relative orientation of the two acidic groups was important for optimal binding. Replacement of the carbonyl group of the benzophenone with a variety of polar and nonpolar linking groups led to only small changes in binding affinity, indicating the linking group may not be involved in receptor recognition. Further structure-activity relationships within this series are reported in an accompanying paper.

Benzophenones↗

PubMed1976

Synthesis and pharmacology of novel anxiolytic agents derived from 2-[(dialkylamino)methyl-4H-triazol-4-yl] benzophenones and related heterocyclic benzophenones.

A series of novel [(dialkylamino)methyl-4H-1,2,4-triazol-4-yl]benzophenones and related compounds has been prepared via total synthesis from substituted aminodiphenylmethanes or by hydrolysis and subsequent methylation of triazolobenzodiazepines. These new triazole compounds were found to have potent sedative and muscle relaxing activity in mice (i.e., these compounds depressed the traction and dish reflexes). In addition, the title compounds antagonized the clonic convulsions induced in mice by the administration of pentylenetratrazole (Metrazol, 85 mg/kg), with ED50's varying from 2.0 to 23.0 mg/kg, and the lethality induced by thiosemicarbazide, with ED50's varying from 0.02 to 9.0 mg/kg. In several biological tests, the potency of seven new benzophenone derivatives approached or exceed that of diazepam (35a) or its glycylaminobenzophenone analogue 36.

Animals↗

PubMed1992

[Anti-arrhythmic action of some amidinohydrazone substituted benzophenones. 1. Synthesis of new amidinohydrazone and N-phenylamidinohydrazone substituted benzophenones].

The title compounds are synthesized as a rule by condensation of substituted benzophenones and derivatives of aminoguanidine in the presence of up to 2.5 moles of an anorganic acid. They can be obtained alternatively via corresponding hydrazones, thiosemicarbazones or methylthiothiocarbonylhydrazones.

Anti-Arrhythmia Agents↗

PubMed1992

Development and validation of a high-performance liquid chromatographic method for the determination of benzophenone-3 in rats.

A precise, accurate, selective and sensitive liquid chromatographic method for the determination of benzophenone-3 in rat biological fluids and different tissues has been developed. The minimum detection limit for benzophenone-3 was 2.0 ng ml-1 and the retention time was 6.01 min. Standard curves for benzophenone-3 were linear in a wide range of concentrations in methanol and different body fluids, ranging from 6.25 ng ml-1 to 100 micrograms ml-1. To detect benzophenone-3 in rat whole blood after oral administration, HCl hydrolysis was required. Benzophenone-3 was found to produce a peak blood concentration 1 h after administration. Free benzophenone-3 in urine represented a very small percentage during the first 12 h after administration, while a higher concentration of the glucuronide conjugate was detected in the same time period.

Animals↗

PubMed1990

Hydrogen abstraction from lipids by triplet states of derivatized benzophenone photosensitizers.

Laser photolysis techniques have been used to characterize the reactivity of triplet state lipoidal benzophenone derivatives toward fatty acids and glycerides in benzene solution. The reactivities of benzophenone-4-heptyl-4'-pentanoic acid (BHPA) toward fatty acid compounds having different configurations of olefinic bonds have been determined. The rates of hydrogen abstraction are found to be lower when compared with similar measurements using benzophenone alone. However, the contribution of physical quenching of the triplet derivative by double bonds also appears to be slightly lower than that found with benzophenone itself. The hydrogen abstraction efficiencies of three other benzophenone derivatives toward linoleic acid in benzene have also been measured. For benzophenone incorporated into a fatty acid molecule, there is a limited relationship between structure and photoreactivity. Finally, these sensitizers have been incorporated into mixed SDS/linoleate micelles to determine the effects of molecular organization on photochemical behavior of the sensitizer and lipid.

Benzophenones↗

PubMed1991

Analysis of benzophenones by gas chromatography/Fourier transform-infrared spectrometry.

A gas chromatograph/Fourier transform-infrared spectrometric analysis of benzophenones, as hydrolyzed products of benzodiazepine, was evaluated and the vapor phase spectra obtained were compared with those measured in the condensed phase. Each infrared spectrum obtained in the vapor phase showed a much greater difference in comparison to differences found in those in the condensed phase, especially in the fingerprint region. The identification of 14 benzophenones by their infrared spectra in the vapor phase was possible. The detection limits for these benzophenones were between 50-100 ng with high signal-to-noise ratios. The vapor phase spectra of the benzophenones were unique and the analytical method allowed the differentiation of closely related classes of drugs, such as benzophenones.

Benzodiazepines↗

PubMed1989

Photointeraction of benzophenone triplet with lysozyme.

The quenching of the benzophenone triplet by lysozyme and its constituent amino acids in aqueous solutions have been studied. Native lysozyme quenches the benzophenone triplet with a high rate constant, 4 x 10(9) M-1 s-1. The quenching process takes place with production of significant amounts of free ketyl radicals, phi ketyl = 0.56, but with a very low benzophenone consumption yield (0.022). The consumption yield is considerably smaller than that observed for the free amino acids. This difference can be explained in terms of a dominant back hydrogen transfer to the protein in the disproportionation of the free radicals produced. Reduced and carboxymethylated lysozyme shows a higher quenching rate (7.8 x 10(9) M-1 s-1) and a larger benzophenone consumption yield (0.07). The deactivation of the benzophenone triplet by the native protein leads to its inactivation, with a quantum yield of 0.01. Tryptophan and arginine residues are destroyed with a quantum yield of 0.01. In the modified enzyme tyrosine and methionine groups are also consumed.

Amino Acids↗

PubMed1991

Further studies on ultraviolet-absorbing hydrogels for intraocular lenses: relationship between concentration of a polymerizable benzophenone, absorption, and extractability.

A tendency to reduce the use of benzophenone absorbers is currently evident in the manufacture of the UV-absorbing IOLs, mainly because the cutoff wavelengths are inferior to those provided by benzotriazoles. In principle, by incorporating large amounts of benzophenones it may be possible to achieve high cutoff wavelengths. A covalently bondable benzophenone UV absorber, Cyasorb UV-2098, was incorporated in poly(2-hydroxyethyl methacrylate) (PHEMA) in increasing concentrations, and certain associated phenomena were investigated. At 4% w/w absorber content, the nonhydrated polymers turned partially opaque. In water-swollen hydrogels, opacification occurred at a lower absorber content (2% w/w). By using extraction techniques and gas chromatography, we also found that up to 8% w/w of the absorber remained unpolymerized and could leach out from any material containing less than 5% w/w absorber. In samples with higher initial content of absorber, the amount of unreacted, leachable absorber was significantly higher (25% to 30%). Based on this study model (hydrogel/Cyasorb UV-2098), we concluded that benzophenone absorbers cannot provide cutoff wavelengths higher than those provided by benzotriazoles.

Acrylates↗

PubMedDate not supplied

Rapid isolation with Sep-Pak C18 cartridges and wide-bore capillary gas chromatography of benzophenones, the acid-hydrolysis products of benzodiazepines.

A simple extraction procedure with a Sep-Pak C18 cartridge for benzophenones and their detection after separation by wide-bore capillary gas chromatography (GC) are presented. The benzodiazepine-containing samples, after heating in acid and centrifugation, were passed through the cartridges and eluted with chloroform. Except for bromazepam, the recoveries of benzodiazepines detected as benzophenones were excellent. Separation of each benzophenone peak from impurities was achieved with an intermediately polar HP-17 capillary column. Electron capture detection gave sensitivity more than 10 times higher than that of flame ionization detection.

Acids↗

PubMed1987

Positive and negative ion mass spectrometry of benzophenones, the acid-hydrolysis products of benzodiazepines.

Positive electron impact (EI), positive chemical ionization (CI), and negative CI mass spectra of 14 benzophenones are presented. In the positive EI mode, intense molecular peaks appeared for most compounds; some other peaks due to splitting at both sides of the carbonyl group also appeared. In the positive CI mode, [M + 1]+ quasi-molecular ions together with [M + C2H5]+ peaks were observed for all compounds; some fragment peaks were common to those in the positive EI mode. In the negative CI mode, the spectra were much simpler than those in the positive EI or CI mode. In the 1 Torr negative CI mode, some spectra showed only single molecular anions; in the 0.01 Torr negative CI mode, halogen or nitro peaks appeared in addition to the molecular anions. An extraction procedure for benzophenones from human urine and plasma after heating in strong acid, and their separation by gas chromatography (GC) are also presented to serve for their actual identification by GC/mass spectrometry.

Benzophenones↗

PubMed1985

The conformation of the C-terminal region of actin: a site-specific photocrosslinking study using benzophenone-4-maleimide.

The site-specific photocrosslinker, benzophenone-4-maleimide, was used to label G-actin specifically at Cys-374, the penultimate residue from the C terminus. The resultant BP-G-actin was polymerized to form BP-F-actin, and both forms of actin were irradiated to activate the benzophenone moiety. We found that for BP-F-actin both intersubunit and intrasubunit photocrosslinks were formed. For BP-G-actin only a small amount of an internally photocrosslinked species was formed. These findings suggest that in the F-actin polymer, the C-terminal peptide is localized in a region between neighboring subunits. In contrast, in the G-actin monomer, the C-terminal peptide is relatively distant from the surface of the molecule.

Actins↗

PubMed1975

An improved benzophenone procedure for the micro-determination of 5,5-diphenylhydantoin in blood.

A micro-modification of the benzophenone procedure proposed by Wallace for the determination of 5,5-diphenylhydantoin in blood is described which does not require specialised glassware and avoids the interferance caused by chloroform. In the new procedure 5,5-diphenylhydantoin is extracted from blood with 1,2-dichloroethane, returned to alkali, washed with n-heptane, and oxidised with permanganate in small teflon lined screw capped test tubes containing a layer of n-heptane. The absorbance of the oxidation product (benzophenone) is measured spectrophotometrically on an expanded scale using semi micro cuvettes. The method requires 100-200 mul sample and has a detection threshold of less than 0.1 mg/100 ml.

Benzophenones↗

PubMed1985

Inhibitory effects of tannic acid and benzophenone on soybean lipoxygenase and ram seminal vesicle cyclooxygenase.

Soybean lipoxygenase and cyclooxygenase from ram seminal vesicles were inhibited by tannic acid and the apparent ID50's were 7.5 x 10(-7) M and 6 x 10(-6) M, respectively. The inhibition of lipoxygenase by tannic acid was noncompetitive. Benzophenone inhibited cyclooxygenase, and the ID50 was 8 x 10(-7) M. The inhibition constant, Ki values of both tannic acid and benzophenone are presented.

Animals↗

PubMed1977

[Analysis of benzodiazepines and their hydrolysis products, benzophenones, by reversed-phase high-performance liquid chromatography and its application to biological material (author's transl)].

Conditions for the routine separation of some benzodiazepines and their hydrolysis products, benzophenones, by reversed-phase high-performance liquid chromatography have been developed. They were applied to the qualitative and quantitative determination of benzodiazepines and benzophenones in biological material, e.g., blood and urine.

Benzodiazepines↗

PubMed1989

Benzodiazepines identified by capillary gas chromatography-mass spectrometry, with specific ion screening used to detect benzophenone derivatives.

We developed algorithms for confirmation and identification of benzodiazepines and their metabolites, initially detected in urine samples by enzyme-multiplied immunoassay (EMIT). These algorithms are based on the pattern of benzophenone derivatives of benzodiazepines obtained by gas chromatography-mass spectrometry (GC-MS) with use of a modified specific ion selection mode. Benzophenone derivatives were produced by acid hydrolysis of urine samples containing benzodiazepines and (or) their metabolites. We present mass spectra of the newer benzodiazepines--alprazolam, midazolam, and triazolam--and we determined the detection limit (0.2 mg/L) for these drugs as measured with the EMIT d.a.u. benzodiazepine assay and the ETS instrument (both from Syva Co.). We conclude that these algorithms are useful mostly in forensic toxicology in which unequivocal identification of benzodiazepines is the desired goal.

Alprazolam↗

PubMed1985

Aldose reductase inhibitors: flavonoids, alkaloids, acetophenones, benzophenones, and spirohydantoins of chroman.

The inhibitory activity of various compounds, including 12 flavonoids, 10 alkaloids, 15 benzophenones, 5 acetophenones, and 7 spirohydantoins of chroman, was tested on rabbit lens aldose reductase, an enzyme involved in complications of diabetes. Almost all compounds tested were found to inhibit the enzyme at low concentrations (10(-5) M). The most potent inhibitor was 2R,4S-6-chloro-2-methylspiro(chroman-4,4'-imidazo-lidine+ ++)-2',5'-dione with an I50 value of 4.7 x 10(-8) M; other spirohydantoins showed similar potency. Polyhydroxybenzophenones were also potent inhibitors with an I50 value of about 10(-7) M. The possible structure-inhibitory activity relationships of the compounds tested are discussed.

Acetophenones↗

PubMed1991

Safety evaluation of benzophenone.

Benzophenone (FEMA No. 2134; CAS No. 119-61-9) was administered in the diet to rats at target dose levels of 20 mg/kg body weight/day for 90 days and 100 or 500 mg/kg/day for 28 days. Body weights and food consumption were measured weekly; haematology, clinical chemistry and urinalysis values were obtained at 4 wk and at the end of the study. Gross and microscopic pathological examinations were conducted and organ weights were recorded. Treatment-related changes occurred in erythrocyte count, haemoglobin, haematocrit, bilirubin, total protein and albumin at the mid- and high-dose levels, although all changes did not occur in both groups in both sexes. There were indications of increased absolute and relative liver and kidney weights in the mid- and high-dose groups, but this was not statistically consistent for absolute kidney weights. Histopathology of the liver in the mid- and high-dose groups showed hepatocellular enlargement with an associated clumping of cytoplasmic basophilic material around the central vein. A no-effect level was demonstrated at 20 mg/kg/day for 90 days of administration. This would be equivalent to an intake of 1200 mg/day for a 60-kg human. On the basis of the calculated Possible Average Daily Intake of 0.33 mg/day, a safety factor of greater than 3600 is demonstrated. The safety factor based on the more realistic per capita consumption of 0.32 microgram/day would be approximately 3.7 million.

Administration, Oral↗

PubMed1975

Electron-capture gas chromatography of methadone after oxidation to benzophenone.

A procedure for the determination of low levels of methadone (6-dimethylamino-4,4-diphenylheptanone-3) in serum has been developed. Methadone is extracted from serum into n-heptane and re-extracted into an acidic aqueous phase. Methadone is oxidized to benzopheone with barium peroxide in sulphuric acid, during which procedure an n-heptane phase is present into which the oxidation product is continuously extracted. The benzophenone formed is determined by means of electron-capture gas chromatography. The recoveries are 100 +/- 3% and 100 +/- 4.5% at the 120 and 16 ng levels, respectively. The minimum amount that can be determined in 1 ml of serum is 4 ng. Interferences from possible metabolies are probably minor. The main cyclic metabolite is only co-determined to a minor extent if the oxidation time is optimized. Comparison of this oxidation method with a combined gas chromatographic-mass spectrometric determination with selected ion monitoring showed identical serum levels.

Benzophenones↗