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PubMed2005

Comparison of microemulsion electrokinetic chromatography and micellar electrokinetic chromatography as methods for the analysis of ten benzophenones.

Microemulsion electrokinetic chromatography (MEEKC) and micellar electrokinetic chromatograpy (MEKC) were compared for their abilities to separate and detect ten similar benzophenones, which are commonly used as UV filters in various plastic and cosmetic products. Sodium dodecyl sulfate (SDS) concentration and column temperature rarely affected separation resolution for MEEKC, but separation of benzophenones could be improved by changing the SDS concentration and column temperature for MEKC. Buffer pH and ethanol (organic modifier) were found to markedly influence the separation selectivity for both MEEKC and MEKC systems. In addition, a higher electric voltage improved the separation efficiency without a noticeable reduction in separation resolution for MEEKC, whereas it caused a poor separation resolution for the MEKC system.

Benzophenones↗
PubMedDate not supplied

Pharmacokinetics of benzophenone-3 after oral exposure in male rats.

Benzophenone-3 (BZ-3) is one of the UV-absorbing agents that has been used in industry and medicine for more than 30 years. Millions of consumers are exposed to benzophenones on a daily basis owing to the widespread use of these compounds in many of the products on the market, such as lipsticks, hair sprays, hair dyes, shampoo and detergent bars and sunscreen lotions. This study was performed to investigate the pharmacokinetics of BZ-3 after oral administration at 100 mg kg-1 body weight in male Sprague-Dawley rats. Absorption from the gastrointestinal tract was rapid because BZ-3 was detected in blood 5 min after administration. The peak plasma concentration (Cmax) was 25.6 +/- 4.6 micrograms ml-1 and the time of occurrence (tmax) was 3.0 +/- 0.4 h. The half-life of absorption of BZ-3 was 0.71 h. The elimination pattern was biphasic with alpha and beta half-lives of elimination of 0.88 and 15.90 h, respectively. The results of this study indicate the presence of strong binding between the plasma protein and BZ-3. Tissue distribution studies at 6 h indicate that the liver contained the highest concentration of free (58.9 +/- 23.8 micrograms) and total (free+bound or conjugated) BZ-3 (2087 +/- 60.1 micrograms), followed by kidney and testes, respectively. Urine and feces analysis indicate that urine was the major route of excretion, followed by feces. Further analysis of urine samples also indicates that conjugation of BZ-3 with glucuronic acid was the major systemic elimination route for the compound.

Administration, Oral↗
PubMed2003

Investigation of apparent mass deviations in electrospray ionization tandem mass spectrometry of a benzophenone-labeled peptide.

In a previous study utilizing benzophenone-based topological probes to study conformationally dependent changes in mouse muscle nicotinic acetylcholine receptor (nAChR) topology, electrospray ionization tandem mass spectrometric (ESI-MS/MS) analysis led to a consistent -2.0 Da mass deviation from expected values. In the present study a synthetic peptide, corresponding to nAChR alpha1 subunit residues 130-139, was photolabeled. MS/MS analysis of this peptide using an ion trap confirmed the previously observed mass deviation, associated only with fragment ions that contain the incorporated benzophenone moiety. Analysis of peak profiles for the photolabeled ions does not indicate the typical 'peak fronting' that produces a mass shift when labile ions are prematurely ejected from the ion trap. Rather, hydrogen/deuterium (H/D) exchange experiments support the hypothesis that a chemical rearrangement involving phenyl migration and ketone formation has formed an unexpected oxidized peptide, with molecular mass 2 Da less than that expected, that is isolated for collision-induced dissociation in the ion trap together with the predicted precursor due to the broad ion isolation window specified.

Benzophenones↗
PubMed2004

Characterization of gallotannins and benzophenone derivatives from mango (Mangifera indica L. cv. 'Tommy Atkins') peels, pulp and kernels by high-performance liquid chromatography/electrospray ionization mass spectrometry.

Polyphenolics were extracted from peels, pulp and kernels of mango fruits (Mangifera indica L. cv. 'Tommy Atkins') and characterized by high-performance liquid chromatography/electrospray ionization mass spectrometry. In the peel 18 gallotannins and five benzophenone derivatives were detected which were tentatively identified as galloylated maclurin and iriflophenone glucosides. Twenty-one and eight gallotannins were found in the kernels and pulp, respectively, whereas no evidence for the presence of benzophenone derivatives was obtained. Gallotannins quantified by the rhodanine assay amounted to 1.4 mg/g dm in the peels (expressed as gallic acid), while only small amounts (0.2 mg/g dm) were found in the pulp. In contrast, mango kernels contained 15.5 mg/g dm and thus proved to be a rich source of gallotannins.

Benzophenones↗
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↗
PubMed2004

Synthesis and anti-inflammatory activity of benzophenone analogues.

A series of substituted benzophenone analogues has been synthesized and evaluated as orally active anti-inflammatory agents with reduced side effects. The anti-inflammatory and ulcerogenic activities of the compounds were compared with naproxen, indomethacin, and phenylbutazone. In carrageenan-induced foot pad edema assay, benzophenone analogues showed an interesting anti-inflammatory activity. In the air-pouch test, some of the analogues reduced the total number of leukocytes of the exudate, which indicates inhibition of prostaglandin production. Side effects of the compounds were examined on gastric mucosa, in the liver and stomach. None of the compounds showed significant side effects compared with nonsteroidal anti-inflammatory drugs such as indomethacin and naproxen.

Administration, Oral↗
PubMed2004

SAR of benzoylpyridines and benzophenones as p38alpha MAP kinase inhibitors with oral activity.

Benzoylpyridines and benzophenones were synthesized and evaluated in vitro as p38alpha inhibitors and in vivo in several models of rheumatoid arthritis. Oral activity was found to depend upon substitution: 1,1-dimethylpropynylamine substituted benzophenone 10b (IC50: 14 nM) and pyridinoyl substituted benzimidazole 17b (IC50: 21 nM) showed highest efficacy and selectivity with ED50s of 9.5 and 8.6 mg/kg p.o. in CIA.

Animals↗
PubMed2005

Xanthones and benzophenones from Garcinia griffithii and Garcinia mangostana.

A new polyisoprenylated benzophenone, guttiferone I, together with the known compounds cambogin, 1,7-dihydroxyxanthone, 1,3,6,7-tetrahydroxyxanthone and 1,3,5,6-tetrahydroxyxanthone were isolated from the stem bark of Garcinia griffithii. The acetone extract of the heartwood of Garcinia mangostana contained one new diprenylated xanthone (mangoxanthone) and a new benzophenone (3',6-dihydroxy-2,4,4'-trimethoxybenzophenone) as well as the known xanthones dulxanthone D, 1,3,7-trihydroxy-2-methoxyxanthone, 1,3,5-trihydroxy-13,13-dimethyl-2H-pyran[7,6-b]xanthen-9-one. Their structures were established on the basis of spectroscopic studies and chemical correlation.

Benzophenones↗
PubMed1982

High-performance liquid chromatography of benzophenone derivatives for the determination of benzodiazepines in clinical emergencies.

A screening procedure for fifteen 1,4-benzodiazepines in biological material (urine), suitable for clinical toxicology, is described. The benzodiazepines and/or their metabolites are hydrolysed to their benzophenones; after alkalinization, the benzophenones are extracted with chloroform. The extract is evaporated to dryness and the dried residue is dissolved in methanol and analysed by high-performance liquid chromatography on a reversed-phase column at 254 nm with methanol-water (1:1) as eluent.

Benzodiazepines↗
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↗
PubMed2000

Two polyisoprenylated benzophenones from the trunk latex of Clusia grandiflora (Clusiaceae).

The polyisoprenylated benzophenones, chamones I and II, were isolated from the trunk latex of Clusia grandiflora (Clusiaceae) growing in southeastern Venezuela. A third benzophenone, nemorosone II, was isolated from the pollinator reward resin of the female flowers of the same plant. Chamone I and nemorosone II are structurally similar, differing only in the degree of prenylation. Bioassays of chamone I and nemorosone II using the honeybee pathogens, Paenibacillus larvae and Paenibacillus alvei, demonstrate that both have potent antibacterial activity, and that their structural differences affect both their bactericidal efficacies and their aqueous mobilities.

Benzophenones↗
PubMed2000

Polyisoprenylated benzophenones from Clusia floral resins.

From the floral resins of various Clusia species, seven polyisoprenylated benzophenones were isolated. HPLC allowed their quantification in all resins, revealing a distribution of benzophenone derivatives distinct from each other. In some species the staminal oils were collected and oleic, stearic and palmitic acids were the main constituents.

Benzophenones↗
PubMed2001

Natural and synthetic benzophenones: interaction with the cytosolic binding domain of P-glycoprotein.

A benzophenone glycoside has been isolated from Davallia solida. Its structure was elucidated by chemical and spectral means as 4-O-beta-D-glucopyranosyl-2,6,4'-trihydroxybenzophenone. It bound with moderate affinity to the purified C-terminal cytosolic domain of P-glycoprotein, but the binding affinity was 6- to 10-fold increased for its aglycone derivative and other related benzophenones.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Benzophenone-3: rapid prediction and evaluation using non-invasive methods of in vivo human penetration.

The study described in this paper constitutes a practical assay system to evaluate in vivo drug penetration using two complementary non-invasive methods. An electrical capacitance test was first applied to the skin on the forearm to evaluate the hydration of the skin, and check the integrity of the stratum corneum. In the first step, the percentage absorption was measured using an occlusive and difference method; following benzophenone-3 application any residual formulation was washed off and the amount removed analyzed. In the second step, the tape stripping method-a useful procedure for selectively removing the skin's outermost layer, the stratum corneum, and measuring the stratum corneum adsorption-was performed. Under these conditions the human skin permeation of this UV-filter over four hours was near to 35% of the applied dose with the occlusive method. The amount of topically applied benzophenone-3 found in the stratum corneum after 30 min exposure using the stripping procedure was evaluated at 4% to the applied dose.

Adult↗