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PubMed2006

Simultaneous determination of benzophenone-type UV filters in water and soil by gas chromatography-mass spectrometry.

A novel method has been developed to simultaneously determine and quantify seven organic UV filters employing liquid (solid)-liquid extraction, derivatization with N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA) and gas chromatography with mass spectrometric detection in various environmental matrices. The UV filters determined were: benzophenone (BP), benzhydrol (BH), 4-hydroxybenzophenone (HBP), 2-hydroxy-4-methoxybenzophenone (HMB), 2,4-dihydroxybenzophenone (DHB), 2,2'-dihydroxy-4-methoxybenzophenone (DHMB) and 2,3,4-trihydroxylbenzophenone (THB). Under optimal conditions, the analysis required 23 min and good linearity over the range of 10-2,500 ng/L in water and 100-25,000 ng/kg in soil for each UV filter obtained. The high recovery (62-114% and 60-125% for water and soil samples, respectively) and the low RSD values (less than 13.9 and 17.2% for water and soil samples, respectively) indicated the high performance of this method. The method detection limits (MDLs) were relatively low, ranging from 5 to 100 ng/L or kg and quantification limits ranged between 25 and 500 ng/L or kg for all test compounds. This validated method was applied in the analysis of seven BP-type UV filters collecting water and soil samples in Korea, between April and May 2003. The overall concentration of UV filters in the soil sample (500-18,380 ng/kg) was highly distributed in water sample (27-204 ng/L). The established method was successfully applied to monitor the residue measurement of the BP-type UV filters in environmental water and soil samples.

Acetamides↗

PubMed2004

New polyisoprenylated benzophenones from Venezuelan propolis.

Two new polyisoprenylated benzophenones, 18-ethyloxy-17-hydroxy-17,18-dihydroscrobiculatone A and 18-ethyloxy-17-hydroxy-17,18-dihydroscrobiculatone B, together with the known scrobiculatones A and B, were isolated from Venezuelan propolis. The scrobiculatones A and B showed significant antibacterial activity and moderate toxicity to Artemia salina nauplii.

Animals↗

PubMed2006

Identification and quantification of two biologically active polyisoprenylated benzophenones xanthochymol and isoxanthochymol in Garcinia species using liquid chromatography-tandem mass spectrometry.

A sensitive liquid chromatography/electrospray ionization tandem mass spectrometrical (LC/ESI-MS/MS) method was developed for the identification and quantification of two polyisoprenylated benzophenones xanthochymol and isoxanthochymol in the extracts of the fruit rinds, stem bark, seed pericarps and leaves of Garcinia indica and in the fruit rinds of Garcinia cambogia. The separation of xanthochymol and isoxanthochymol was achieved on a RP-18 column using the solvent system consisting of a mixture of acetonitrile-water (9:1) and methanol-acetic acid (99.5:0.5) as a mobile phase at a flow rate of 0.4ml/min. A multiple reaction monitoring (MRM) method was developed for quantification of xanthochymol and isoxanthochymol in the above extracts of Garcinia species. On the basis of signal to noise ratio of 3, the limits of detection in MRM mode for xanthochymol and isoxanthochymol were 1.0ng/ml and 0.5ng/ml, respectively. The method was validated in terms of linearity, accuracy and precision for 6 days. The method developed was found to be useful for identification and quantification of xanthochymol and isoxanthochymol in the extracts of the fruit rinds, stem bark, seed pericarps and leaves of G. indica and in the fruit rinds of G. cambogia.

Benzophenones↗

PubMed2005

Scaled quantum chemical calculations and FTIR, FT-Raman spectral analysis of 3,4-diamino benzophenone.

The vibrational spectra of 3,4-diamino benzophenone (DABP) have been computed using B3LYP methodology and 6-31G* and 6-31G** basis sets. The solid phase FTIR and FT-Raman spectra were recorded in the region 4000-400 cm-1 and 3500-100 cm-1, respectively. A close agreement was achieved between the observed and calculated frequencies by employing normal coordinate calculations. The observed and simulated spectra were found to be well comparable.

Benzophenones↗

PubMed2004

Multi-organic endocrine disrupting activity of the UV screen benzophenone 2 (BP2) in ovariectomized adult rats after 5 days treatment.

The chemical industry has developed sun protection factor products, which contain a variety of so-called "UV screens", among others, benzophenones (BP). Based on the structure it can be assumed, that the variant BP2 may be a potent estrogenic endocrine disrupter (ED). Only very limited data are available in the literature about such action of BP2, which focussed on the uterotrophic effect in immature rats. However, determination of ED activity in the uterus is only a restricted approach with the potential risk of missing undesirable actions. Therefore, we examined a putative multiple organ ED activity of BP2 by measuring gene expression of marker genes in the uterus, liver, vagina and pituitary after 5 days oral application in adult ovariectomized (ovx) rats. An effect on lipid metabolism was assessed by determination of cholesterol, high- and low-density lipoproteins (HDL and LDL) in the blood. As control compound, estradiol (E2) was included in the study. A dose dependent E2-agonistic activity was observed in the uterus (increased weight), vagina (increased IGF1 expression), pituitary (reduced LH synthesis), liver (increased IGF1 expression) and lipid parameters (reduction). A non-E2-like action of BP2 was observed on T4- and T3-levels, which were significantly reduced. Except for the action of BP2 on thyroid hormone levels where it may inhibit thyroid peroxidase, this UV screen exerts clear E2-agonistic actions. Application of BP2 for 5 days proved to be a sufficient treatment period to unravel a multi-organic endocrine disrupting activity of this UV screen.

Animals↗

PubMed2004

Pure estrogenic effect of benzophenone-2 (BP2) but not of bisphenol A (BPA) and dibutylphtalate (DBP) in uterus, vagina and bone.

UNLABELLED: Contradictory results whether the endocrine disrupters (ED) benzophenone-2 (BP2), bisphenol A (BPA) and dibutylphtalate (DBP) exert estrogenic effects have been published. Selective estrogen receptor modulators (SERMs) exert estrogenic effects in some but not in all organs and ED may be SERMs. Therefore, we studied their binding properties to recombinant ERalpha and ERbeta protein and their effects in the uterus, vagina and bone of ovariectomized rats. BP2 bound to both receptor subtypes, while BPA had a relatively high ERbeta selectivity. DBP did not bind to ERalpha but with a low affinity to ERbeta. In the uterus, only E2 and BP2 increased uterine weight and the complement C3 but decreased ERbeta gene expression. Discrete effects of BPA and DBP in the uterus were found upon histological examination. In the vagina, BP2 but not BPA and DBP had clear estrogenic effects. E2 and BP2 had antiosteoporotic effects in the metaphysis of the tibia. The serum surrogate parameters of bone metabolism, i.e. osteocalcin and the cross (rat) laps were significantly reduced by E2, an effect shared with BP2 but not by the two other EDs. THE CONCLUSION: BP2 acts as ERalpha and ERbeta agonist mimicking effects of E2, while the effects of BPA and DBP are not pure estrogenic.

Animals↗

PubMed2006

Formation of estrogenic products from benzophenone after exposure to sunlight.

Benzophenone (BP) is a suspected endocrine disrupter that is found in our environment. BP undergoes metabolic and photochemical activation. In this study, photoproducts of BP were identified using high-performance liquid chromatography and mass spectrometry and their estrogenic activity was determined using both in vitro and in vivo assays. Although BP showed no estrogenic activity, two estrogenic photoproducts were detected after irradiating an aqueous solution of BP with UV or sunlight. These active products were identified as 3-hydroxy BP (BP-3OH) and 4-hydroxyBP (BP-4OH). The formation of hydrogen peroxide H2O2) was detected with increasing levels of UV, and the addition of H2O2 to the BP solution increased BP-3OH and BP-4OH production under UV irradiation. BP hydroxylation was also observed in the reaction with the Fenton reagent generating hydroxyl radical without UV irradiation. These results suggest the involvement of photochemically generated H2O2 and hydroxyl radical in the BP hydroxylation. BP-4OH was more potent than BP-3OH for promoting estrogen receptor (ER)-mediated transcription and uterotrophic activity, although both of them showed same affinity in ER binding. In conclusion, BP can be converted into ring-hydroxylated derivatives that have estrogenic activity after exposure to light.

Animals↗

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↗

PubMed1988

Collection of analytical data for benzodiazepines and benzophenones.

On April 1st, 1986, amendments were made to Schedule 2 to the Misuse of Drugs Act 1971 such that 33 benzodiazepines became controlled as Class C drugs in the U.K. An analytical database has been prepared to aid the detection and identification of controlled benzodiazepines. Chromatographic properties have been measured including gas chromatography (GC) retention index values, high-performance liquid chromatography (HPLC) capacity factors and thin-layer chromatography (TLC) RF x 100 values. UV spectroscopic and mass spectrometric (MS) data have also been recorded. Analytical data (GC, TLC and MS) are also presented for benzophenones which were produced by acid hydrolysis of the parent benzodiazepines.

Benzodiazepines↗

PubMed1998

Gas chromatographic-mass spectrometric confirmation of selected benzophenones from benzodiazepines in human urine following automatic screening.

This paper reports a simple, expeditious procedure for confirming the presence of benzodiazepines in previously screened positive urine samples. Samples are manually hydrolysed to the corresponding benzophenones in an acid medium. The hydrolysis products are continuously aspirated into a photometric flow system for screening; positive samples are then confirmed and benzodiazepines identified by using a different flow system that conditions the analytes for gas chromatographic separation and unequivocal mass spectrometric confirmation. Detection limits for benzodiazepines in the nanogram-per-millilitre region are thus achieved by using 0.5 ml of hydrolysed urine; also, repeatability, as R.S.D., is less than 6.5%. The high specificity and sensitivity of the proposed method enables the confirmation of different benzodiazepines in urine samples obtained from drug addicts and patients from a local hospital.

Benzodiazepines↗

PubMedDate not supplied

Non-thiol farnesyltransferase inhibitors: the concept of benzophenone-based bisubstrate analogue farnesyltransferase inhibitors.

Replacement of the thiol in a benzophenone-based CAAX-peptidomimetic farnesyltransferase inhibitor by a carboxylic acid moiety resulted in a marked drop in inhibitory potency. Transformation of these carboxylic acid derivatives into bisubstrate analogues by addition of a lipophilic alkyl chain, which should be able to occupy considerable portions of the farnesyl binding region in the farnesyltransferase's active site, resulted in a regain of the inhibitory activity. These bisubstrate analogues represent new lead structures for non-thiol farnesyltransferase inhibitors.

Alkyl and Aryl Transferases↗

PubMed2000

Depth-dependent analysis of membranes using benzophenone-based phospholipids.

Any attempt to probe the membrane hydrophobic core with chemical reagents necessitates the use of reactive intermediates like carbenes and nitrenes, which can insert into C-H bonds. Several photoactivable reagents based on carbenes and nitrenes have been reported. However, the high reactivity of these reagents, often leads to very low insertion yields. We report here a high degree of cross-linking (35-40%) achieved with three benzophenone-based phospholipids and analyze the carbon functionalization data using a multiple Gaussian function. These phospholipids are so designed so as to permit depth-dependent labeling in membranes. Single bilayer vesicles were prepared from these phospholipids and dimyristoylphosphatidylcholine. The cross-linked product was isolated and characterized by mass spectroscopy. The results obtained indicated that the cross-linked product was dominated by dimeric product formed by intermolecular cross-linking. The Gaussian analysis used here provides insight into the relative depths of the probes inside the membrane.

Benzophenones↗

PubMed1997

Benzophenone-sensitized photooxidation of sarcoplasmic reticulum membranes: site-specific modification of the Ca(2+)-ATPase.

Benzophenone (BP) was used as a photosensitizer to initiate lipid peroxidation in model and native biological membranes at concentrations of BP that do not perturb bilayer structure, as assessed by stearic acid spin label dynamics. Illumination of BP partitioned into sarcoplasmic reticulum membranes (SR) results in an exponential decay of BP and a linear accumulation of conjugated dienes and other products of lipid peroxidation as observed previously for micelles of linoleic acid [Marcovic and Patterson. Photochem. Photobiol. 58:329-334, 1993]. Lipid peroxidation was substantially inhibited in the presence of membrane-spanning proteins in SR compared to protein-free lipid vesicles, suggesting the competitive reaction of the initiator (triplet BP) and BP-derived radical species with protein groups. Modification of the predominant integral membrane protein, the Ca(2+)-ATPase, was demonstrated by changes in Ca(2+)-ATPase amino acid composition as well as by its functional inhibition. The rate of calcium transport showed an immediate exponential decay to completion, while calcium-dependent ATPase activity exhibited an initial lag before modest inactivation. These results are consistent with the respective localization of calcium transport sites within membrane-spanning peptides and the ATP-binding site within the cytosolic domain of the Ca(2+)-ATPase, further suggesting that photosensitization of BP models oxidative stress inside the hydrophobic interior of the SR membrane.

Amino Acids↗

PubMed2000

Synthesis and preliminary analysis of a P-glycoprotein-specific [3H]-benzophenone photoaffinity label based on (-)-stipiamide.

A benzophenone photoaffinity label 9 based on the polyene natural product (-)-stipiamide has been constructed using a diaminoethane spacer and the radioactive agent [3H]-BZDC (N-succinimidyl p-benzoyl-(2,3-3H)-dehydrocinnamate). Photoaffinity experiments show specific binding to human P-glycoprotein (Pgp) in the presence of cis-flupentixol but not with cyclosporin A.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

The design, synthesis, and initial evaluation of benzophenone-containing peptides as potential photoaffinity labels of oligosaccharyltransferase.

The benzophenone photophore was incorporated into protected tripeptides and tetrapeptides as photoactivatable probes to study the multimeric enzyme oligosaccharyltransferase (OST). These peptides contain the -Asn-X-Thr- sequon which is required for OST-catalyzed N-glycosylation. Two tripeptides, Bz-Asn-Bpa-Thr-NH2 (3b) and Bz-Asn-Lys[N epsilon-(4-Bz)Bz]-Thr-NH2 (4b), were found to be good OST substrates. They were competitive inhibitors versus standard peptide substrate [14C]Bz-Asn-Leu-Thr-NH2 and their Ki values were determined to be 41 +/- 6 microM and 21 +/- 6 microM, respectively, using synthetic (GlcNAc)2-PP-dolichol.

Benzophenones↗

PubMed2005

Optical fiber immunosensor based on a poly(pyrrole-benzophenone) film for the detection of antibodies to viral antigen.

We describe herein a newly developed optical microbiosensor for the diagnosis of hepatitis C virus (HCV) by using a novel photoimmobilization methodology based on a photoactivable electrogenerated polymer film deposited upon surface-conductive fiber optics, which are then used to link a biological receptor to the fiber tip through light mediation. This fiber-optic electroconductive surface modification is done by the deposition of a thin layer of indium tin oxide on the silica surface of the fiber optics. Monomers are then electropolymerized onto the conductive metal oxide surface; thereafter, the fibers are immersed in a solution containing HCV-E2 envelope protein antigen and illuminated with UV light (wavelength approximately 345 nm). As a result of the photochemical reaction, a thin layer of the antigen becomes covalently bound to the benzophenone-modified surface. The photochemically modified fiber optics were tested as immunosensors for the detection of anti-E2 protein antibody analyte that was measured through chemiluminescence reaction. The biosensor was tested for sensitivity, specificity, and overall practicality. Our results suggest that the detection of anti-E2 antibodies with this microbiosensor may enhance significantly HCV serological standard testing especially among patients during dialysis, which were diagnosed as HCV negative, by standard immunological tests, but were known to carry the virus. If transformed into an easy to use procedure, this assay might be used in the future as an important clinical tool for HCV screening in blood banks.

Benzophenones↗

PubMedDate not supplied

Tethered benzophenone reagents for the synthesis of photoactivatable ligands.

A new radiolabeled, bifunctional photoaffinity cross-linking reagent, N-succinimidyl p-benzoyl-[2,3-3H2]dihydrocinnamate, has been synthesized in high yield and with high specific activity. This reagent can be used to append the benzophenone photophore to amino groups of small molecules, such as O-aminoalkylinositol polyphosphates and polypeptides. The resulting tritiated photoaffinity labels can be purified and manipulated in ambient light and can be activated at 360 nm.

Affinity Labels↗

PubMedDate not supplied

Synthesis of trifunctional PNA-benzophenone derivatives for mitochondrial targeting, selective DNA binding, and photo-cross-linking.

Mutations in mitochondrial DNA (mtDNA) cause a variety of human pathologies. In many patients, mutated and wild-type mtDNAs coexist in the same cell, a situation termed mtDNA heteroplasmy. In the absence of standard therapies for these disorders, a genetic strategy for treatment has been proposed whereby replication of mutated mtDNA is inhibited by the selective hybridization of a nucleic acid derivative, allowing propagation of the wild-type genome and correction of the associated defects. To allow for selective binding under physiological conditions, peptide nucleic acids (PNA) are being used. Two other problems, however, have to be resolved: mitochondrial import and attachment of the PNA to the target DNA to inhibit replication. Mitochondrial localization can be achieved by the addition of a caged lipophilic cation and addition of a photo-cross-linking reagent should facilitate covalent attachment. We therefore report the synthesis of benzophenone-PNA derivatives carrying a triphenylphosphonium moiety and demonstrate irreversible binding selectivity between two DNA molecules that differ by a single nucleotide.

Benzophenones↗