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PubMed2005

[Estrogenic activity of ultraviolet absorbers and the related compounds].

The estrogenic activities of ultraviolet absorbers and their related compounds were investigated using MCF-7 cell proliferation assay. Nine of 33 chemicals (benzophenone, 2,4-dihydroxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 4-hydroxybenzophenone, 3-(4-methylbenzylidene) camphor, ethyl 2-cyano-3,3-diphenylacrylate (etocrylene) and 2-ethylhexyl-2-cyano-3,3-diphenylacrylate (octocrylene)) were positive compared with the vehicle control. Benzhydrol, ethyl cinnamate and 2,2'-dihydroxy-4-methoxybenzophenone were weakly active. When each xenoestrogen was added to the cells along with ICI 182780, an estrogen receptor (ER) antagonist, the cell growth was reduced according to its doses. Therefore, the cell proliferation was suggested to generate through ER. Most of these chemicals were also positive using CHOOSER assay, a new method of testing estrogenic activity of xenoestrogen. Each xenoestrogen was also confirmed to bind to ERalpha and ERbeta using a human ER competitive binding assay against 17beta-estradiol. The concentration order of the strength of its inhibitory effect using both ERalpha and ERbeta was similar to that of MCF-7 cell proliferation assay, except for benzyl 4-hydroxybenzoate (B4HB). B4HB showed a stronger activity on CHOOSER assay and the competitive binding assay using both ERalpha and ERbeta, although there was no activity observed on MCF-7 cell proliferation assay. Our findings were to detect the estrogenic activity of etocrylene and octocrylene in vitro, in addition to confirming the activities of some ultraviolet absorbers as previously reported.

Alkaline Phosphatase↗
PubMed2001

In vitro and in vivo estrogenicity of UV screens.

Ultraviolet (UV) screens are increasingly used as a result of growing concern about UV radiation and skin cancer; they are also added to cosmetics and other products for light stability. Recent data on bioaccumulation in wildlife and humans point to a need for in-depth analyses of systemic toxicology, in particular with respect to reproduction and ontogeny. We examined six frequently used UVA and UVB screens for estrogenicity in vitro and in vivo. In MCF-7 breast cancer cells, five out of six chemicals, that is, benzophenone-3 (Bp-3), homosalate (HMS), 4-methyl-benzylidene camphor (4-MBC), octyl-methoxycinnamate (OMC), and octyl-dimethyl-PABA (OD-PABA), increased cell proliferation with median effective concentrations (EC(50)) values between 1.56 and 3.73 microM, whereas butyl-methoxydibenzoylmethane (B-MDM) was inactive. Further evidence for estrogenic activity was the induction of pS2 protein in MCF-7 cells and the blockade of the proliferative effect of 4-MBC by the estrogen antagonist ICI 182,780. In the uterotrophic assay using immature Long-Evans rats that received the chemicals for 4 days in powdered feed, uterine weight was dose-dependently increased by 4-MBC (ED(50 )309mg/kg/day), OMC (ED(50) 935 mg/kg/day), and weakly by Bp-3 (active at 1,525 mg/kg/day). Three compounds were inactive by the oral route in the doses tested. Dermal application of 4-MBC to immature hairless (hr/hr) rats also increased uterine weight at concentrations of 5 and 7.5% in olive oil. Our findings indicate that UV screens should be tested for endocrine activity, in view of possible long-term effects in humans and wildlife.

Animals↗
PubMed2000

Photoyellowing inhibition of bleached high yield pulps using novel water-soluble UV screens.

To address the deficiencies of benzophenone UV screens for preventing brightness reversion in high yield mechanical papers, we synthesized a new series of such materials with enhanced water solubility and compatibility with the lignocellulosic substrate. A series of 2,4-dihydroxybenzophenones (DHB) were synthesized containing various Mannich bases at the C3 position of one of its rings. They possess the UV-screening ability of o-hydroxylbenzophenones, and they also contain tertiary nitrogen atoms that may function as radical scavengers. Aqueous solutions of the hydrochloride salt of 3-(dimethylaminomethylene)-2,4-dihydroxylbenzophenone (1), when applied on bleached chemithermomechanical pulp (CTMP) sheets, were significantly more efficient in preventing photoyellowing than the original DHB applied on the sheets from ethanol-water solutions. This confirmed our original hypothesis that increasing the compatibility of the UV screen with the lignocellulosic matrix would increase its efficiency in preventing photoyellowing. Compound 1, however, was found to be somewhat more effective than its hydrochloride salt toward preventing photoyellowing. This was attributed to the synergistic action of the free tertiary aminic center attached on the molecule with its UV-screening ability. To comprehend further the various parameters that influence the photoyellowing inhibition performance of these compounds and DHB with bleached CTMP pulp fibers, a series of handsheets were prepared at different pH. The interactions of the protonated compound 1 with pulp fibers were then evaluated by studying their kinetics of absorption and desorption to and from the fiber matrix. This part of our study found that the adsorption of protonated Mannich derivatives of DHB onto pulp is most likely governed by a cation-exchange mechanism involving the cationic amine group with the sulfonic and carboxylic acid groups located on the surface of the fibers. The pH the paper sheet was made from was also found to affect profoundly the adsorption and retention characteristics of these compounds onto the lignocellulosic matrix.

Benzophenones↗
PubMed2000

Photo-oxidation of methionine-containing peptides by the 4-carboxybenzophenone triplet state in aqueous solution. Competition between intramolecular two-centered three-electron bonded (S...S)+ and (S...N)+ formation.

Quantum yields for the formation of transients were measured following the quenching of triplet 4-carboxy-benzophenone (3CB*) by methionine-containing peptides in aqueous solutions. Ketyl radicals (CBH.), ketyl radical anions (CB.-) and various sulfur radical cations were identified following the triplet-quenching events. The presence of these intermediates indicated that the triplet-quenching mechanism can be characterized as mainly electron-transfer in nature. The quenching rate constants were of the order of 2 x 10(9) M-1 s-1. There were small, but significant, differences in the triplet-quenching rate constants, and these trends indicate the existence of multiple sulfur targets in the quenchers. The absorption of the transient products was followed in detail by using spectral-resolution analysis. From the absorption data, quantum yields were estimated for the formation of the various transients. There were differences found in the yields of the transient products between the experiments, where the quenchers were the "mixed" stereoisomers of methionylmethionine (L,D and D,L) and experiments where the quenchers were L,L and D,D stereoisomers. Triplet-quenching data from several other methionine-containing small oligopeptides were analyzed in an analogous manner. Systematic variations were observed, and these patterns were discussed in terms of competitive donation of protons to the CB.- within the charge-transfer complex. The competition was between protons on carbons adjacent to the sulfur-radical center and protons on the protonated amino groups of the radical cation. In addition, there was a competition between the two intramolecular two-centered, three-electron bonded species (S therefore S)+ and (S therefore N)+ that play roles in the secondary kinetics.

Amino Acid Sequence↗
PubMed2003

Use of synthetic isoprenoid analogues for understanding protein prenyltransferase mechanism and structure.

Protein prenylation involves the post-translational modification of specific protein-derived cysteine residues with farnesyl or geranylgeranyl groups through thioether linkages. Because a large number of proteins that participate in signal transduction processes require this modification, there has been intense interest in developing inhibitors of these enzymes and in clarifying the biological function of prenylation. Isoprenoid analogues have proven to be versatile tools for probing the mechanism and structure of prenyltransferases. Mechanistic probes have been created to investigate the stereochemical course and substituent effects in prenyltransferase catalyzed reactions. They have also been used to measure kinetic isotope effects and search for possible cationic intermediates. Photoaffinity labeling analogues containing either diazotrifluoropropionate or benzophenone units have been used to identify the location of isoprenoid binding sites in these enzymes. Biophysical probes incorporating fluorescent moieties or isotopic labels have been used to measure isoprenoid dissociation constants or prenyl group conformation when bound to the enzyme. Analogues containing noncognate alkene isomers or bulky substituents have also contributed to an understanding of isoprenoid recognition. Most recently, photoactive and isomeric isoprenylated analogues are providing insights into the function of protein prenylation.

Benzophenones↗
PubMed1981

Metabolism and macromolecular binding of the carcinogen Michler's ketone in rats.

1. Studies on the metabolism of 14C-Michler's ketone (4,4'-bis-(dimethylamino)[carbonyl- 14C]benzophenone) in rats have revealed that this carcinogen is subject to demethylation, ring-hydroxylation and N-acetylation after adjacent methyl groups have been removed. 2 As identified by mass spectral analysis, microsomal metabolites are the mono-, di-, tri- and tetra-demethylated derivatives. 3. The major metabolites appearing in the bile are the di- and tri-demethylated derivatives and the N-acetylated tetra-demethylated compound; minor metabolites, tentatively identified, are the ring-hydroxylated derivatives of di- and tri-demethylated Michler's ketone and of N-acetylated tri- and tetra-demethylated Michler's ketone. 4. The major urinary metabolite is tentatively identified as a ring-hydroxylated derivative of N-acetylated, di-demethylated Michler's ketone; a minor urinary metabolite lacks the hydroxyl group. 5. Injection of 14C-Michler's ketone into rats resulted in the irreversible binding of radioactivity to liver proteins. 6. When the rats were pretreated with phenobarbital, this binding was increased and extended to proteins of some other tissues and to DNA and RNA of liver and DNA of kidney.

Animals↗
PubMed1976

[Influence of an antispastic, analgesic combination on blood pressure, dynamics and contractility of the left ventricle in the dog].

The following cardiovascular parameters were continuously measured in 12 dogs anaesthetized with sodium pentobarbital following i.v. application of Baralgin, a combination of 1-beta- piperidino-ethoxycarbmethoxy-benzophenone-hydrochloride with diphenylpiperidino-ethyl-acetamide-bromomethylate and 2.3-dimethyl-4-methylamino-1-phenyl-5-pyrazolone-N-methanesulfonic acid: Mean arterial blood pressure, left ventricular pressure, dp/dt-value in the left ventricle, the parameter (see article), told peripheral resistance, cardiac work, heart rate, cardiac output and stroke volume, flow rate in the A. femoralis and the repiration volume. In this experimental series dosages of 0.1, 0.25, 0.625 and 1.56 ml Baralgin/kg i.v. were tested and the subsequent cardiovascular activity was recorded for a period of 90 min following application. 1. The mean arterial blood pressure remained practically unaltered following low doses of Baralgin (0.1 and 0.25 ml/kg i.v.), whereas higher doses (0.625 and 1.56 ml/kg) led to an initial drop in blood pressure corresponding to the fall in total resistance. 2. The cardiac output rose slightly in correlation with rise in stroke volume. In the dosage range of 0.25 ml Baralgin/kg i.v. the rise in cardiac output was accentuated by an increase in heart rate. 3. The cardiac work remained relatively stable following small Baralgin doses, however, a slight diminution in cardiac work due to the fall in blood pressure and decrease in cardiac output, resulted from application of 1.56 mg/kg i.v. 4. A slight positive inotropic stimulation of the heart became apparent in the initial period following small doses of Baralgin (0.1 and 0.25 ml/kg i.v.), higher i.v. dosages caused a marginal reduction in cardiac contractility.

Aminopyrine↗
PubMed2001

Structure-activity relationships of novel anti-malarial agents: 1. arylacyl and cyclohexylacyl derivatives of 5-amino-2-tolylacetylaminobenzophenone.

We have identified compound 1 as a lead structure of a novel class of anti-malarial agents. Here, we report on our continuing studies towards the establishment of structure-activity relationships by varying the terminal phenyl moiety and the alkyl linker of the acyl substituent at the 5-amino function of the benzophenone core structure. Most of the derivatives of our lead structure 1 essentially display the same anti-plasmodial activity as the lead.

Animals↗
PubMedDate not supplied

[Purification of extracts from biological material using aluminum oxide].

An effective, rapid, and safe operation is suggested for purification of extracts from biological material from co-extractive substances during testing for barbiturates, benzophenones, and nichlofolane. The purification is carried out on a column packed with aluminum oxide.

Adsorption↗
PubMed2002

[Screening of benzodizepines and their metabolites in urine].

OBJECTIVE: Screen seventeen benzodizepines and their metabolitesin urine by GC/ECD and GC/MS. METHODS: They were GC (GC/ECD, GC/MS) assay of benzodizepines and GC (GC/ECD, GC/MS) assay of benzophenones of acid-hydrolytic products of 1,4-benzodizepines. RESULTS: The methods were simple and sensitive. The recoverys were 60% to 90% of most benzodizepines, linear calibration curves were 20 ng/ml-200 ng/ml (r > 0.99), and detection limits were 0.5 ng/ml-10 ng/ml. CONCLUSION: They methods were evaluated with human urine samples.

Anti-Anxiety Agents↗
PubMed2003

[Effect of phenazepam metabolite, 2-amino-5-bromo-2'-chlorobenzophenone, on glycine and glutamate NMDA receptors of rat hippocampal pyramidal neurones].

Action of 2-amino-5-bromo-2'-chlorobenzophenone (ABPH), a metabolite of phenazepam, on currents evoked by the activation of glycine and glutamate NMDA receptors has been investigated in enzymatically isolated hippocampal rat pyramidal neurones. It is demonstrated that 3-10 microM ABPH caused an inhibitory effect on glycine receptors which was more prominent after pre-incubation with the drug. Peak amplitude of NMDA receptor-mediated currents was weakly potentiated after prolonged (4-6 min) incubation with 10 microM ABPH. Thus, the effects of the benzophenone metabolites should be taken into account when analysing the action of phenazepam and other benzodiazepine drugs.

Animals↗
PubMed1992

Photoprotective effects of sunscreens in cosmetics on sunburn and Langerhans cell photodamage.

It has become common practice to add sunscreening agents of variable potency to cosmetics to protect against the adverse effects of ultraviolet (UV) radiation exposure. The purpose of this study was to determine whether cosmetic preparations containing sunscreening agents protected against the adverse effects of acute UV radiation exposure and, if so, to identify the components responsible for the photoprotective effects. Pretreatment of skin with one such cosmetic product provided complete protection against UV-induced erythema, sunburn cell formation and Langerhans cell damage in volunteers, skin types II and III, whose skin was exposed to a 1.5 minimal erythema dose daily for 4 consecutive days. When individual components of the cosmetic preparation were analyzed for their photoprotective activities, it was found that both the cinnamate and benzophenone sunscreen combination and an extract of baker's yeast present in the preparation had photoprotective properties. These studies indicate that incorporation of photoprotective agents into cosmetic preparations provides a beneficial function and should therefore be encouraged.

Adolescent↗
PubMed2005

[Metabolic pathways of dipfluzine in rats].

AIM: To investigate the metabolic pathways of dipfluzine in rats. METHODS: After an oral dose of dipfluzine (80 mg x kg(-1)) to rats, urine was collected for 12 h. The metabolites of dipfluzine in urine were chromatographed and identified by LC/DAD/MS methods. RESULTS: In the rat urine, there were 1-(4-fluorophenyl)-4-piperazinylbutanone and its glucuronide, 4-hydroxybenzophenone and its glucuronide, 4-fluoro-gamma-hydroxybenzenebutanoic acid and its glucuronide and sulfate, diphenylmethanol and its glucuronide, dipfluzine, and benzophenone. CONCLUSION: In rats, dipfluzine was mainly metabolized in the pathways of N-desalkylation at 1- and 4-positions of piperazine ring. Some of metabolites were further conjugated with glucuronic acid and/or sulfuric acid.

Animals↗
PubMed2005

Gas-initiation under UV and liquid-grafting polymerization on the surface of polysulfone hollow fiber ultrafiltration membrane by dynamic method.

Using the inner-surface of polysulfone hollow fiber ultrafiltration membranes as grafted layer, the method of gas-initiation and liquid-polymerization has been studied, which aimed to adjust the diameter of the pores in the membranes. The degree of polymerization varied with the changes of the parameters, such as irradiation time, monomer concentration, temperature and time of polymerization and soon. The results indicated that using benzophenone (BP) which is in a gaseous condition as photo-initiator, acrylamide as graft monomer, the polyacrylamide chain was grafted on the surface of membranes. After the surface membrane being modified, the water flux and retention altered, and thus it can be seen that the diameter of the pores in the membrane was altered. These experiments contribute to finding a new way to produce the hollow fiber membrane with the small pore size and are extraordinarily worth developing and studying.

Acrylamide↗
PubMed2006

Estradiol and resveratrol stimulating effect on osteocalcin, but not osteonectin and collagen-1alpha gene expression in primary culture of rat calvarial osteoblast-like cells.

Evidence is available that some endocrine disruptors, acting as selective estrogen receptor modulators (SERMs), interfere with osteoblast differentiation and function. Therefore, we investigated whether 17beta-estradiol, bisphenol-A (BSP), silymarin, genistein, resveratrol, procymidone, linurone and benzophenone-3 (BP3) modulate differentiation of rat calvarial osteoblast-like (ROB) cells in primary in vitro culture. Disruptors were added at day 18 of culture and cells were harvested 48 h later. Real time-PCR revealed that estradiol and resveratrol enhanced osteocalcin mRNA expression in ROB cells, while other disruptors were ineffective. The expression of osteonectin and collagen-1alpha was not affected by any disruptor. Estradiol, resveratrol, genistein and BSP stimulated the proliferative activity of ROB cells. In contrast, procymidone and linurone inhibited the proliferative activity, and silymarin and BP3 were ineffective. The conclusion is drawn that i) only resveratrol is able, like estradiol, to stimulate the specialized functions of ROB cells, and ii) the proliferative activity of ROB cells is more sensitive to endocrine disruptors, some of which could probably act via a mechanism independent of their SERM activity.

Animals↗
PubMed2006

Endocrine disruptors and rat adrenocortical function: studies on freshly dispersed and cultured cells.

The effects of four endocrine disruptors: resveratrol, diphenylolpropane (bisphenol-A; BSP), benzophenone-3 (BP3) and silymarin on the secretory and proliferative activity of rat adrenocortical cells were investigated in vitro. Resveratrol and BP3 acutely increased basal corticosterone secretion from freshly dispersed adrenocortical cells, and resveratrol and BSP enhanced ACTH-stimulated cells. The 24-h exposure to resveratrol and BP3 increased basal corticosterone production from cultured adrenocortical cells, while ACTH-stimulated secretion was increased only by resveratrol. BSP was ineffective, while silymarin decreased basal, but not ACTH-stimulated secretion. The proliferative activity of the cultured adrenocortical cells was unaffected by the tested disruptors. In conclusion, the in vitro direct effect of endocrine disruptors on adrenocortical steroidogenesis displays a great variability, which seems to depend not only on their chemical nature, but also on their dose and the duration of the exposure of the studied cells.

Adrenal Cortex↗
PubMed1990

Ca2(+)-dependent interactions between the C-helix of troponin-C and troponin-I. Photocross-linking and fluorescence studies using a recombinant troponin-C.

We have used in vitro mutagenesis to synthesize in Escherichia coli a recombinant rabbit skeletal troponin-C (designated as TnC57) in which Cys-98 was replaced with leucine, and Ala-57 in the C-helix of the N-terminal domain was replaced with cysteine. TnC57 labeled with the bifunctional photocross-linker benzophenone-4-maleimide could be photocross-linked with troponin-I in both the binary complex with troponin-I and in the ternary complex with troponin-I and troponin-T. The fluorescence lifetime of TnC57 labeled with the probe N-iodoacetyl-N'-(5-sulfo-1-naphthyl)ethylenediamine decreased from 13.2 +/- 0.1 to 11.8 +/- 0.1 ns when Ca2+ bound to the low affinity triggering sites. Complexation with either troponin-I or both troponin-I and troponin-T resulted in significant increases in this lifetime both in the absence and the presence of Ca2+. In either the binary or the ternary complex, this lifetime increased from 15.5 to 18.0 ns upon Ca2+ binding to the low affinity sites. Complementary acrylamide-quenching studies yielded results that are consistent with the fluorescence lifetime results. Our results show that the C-helix of troponin-C interacts with troponin-I, in confirmation of recent zero-length cross-linking results (Leszyk, J., Grabarek, Z., Gergely, J., and Collins, J.H. (1990) Biochemistry 29, 299-304). Moreover, they are in support of a model (Herzberg, O., Moult, J., and James, M.N.G. (1986) J. Biol. Chem. 261, 2638-2644) in which the binding of Ca2+ to the triggering sites in the N-terminal domain of troponin-C results in the movement of the B- and C-helices away from the central helix, thereby exposing a putative hydrophobic binding site for troponin-I.

Animals↗