Oxidative degradation of bisphenol a by crude enzyme prepared from potato

When crude enzymes prepared from some vegetables and fruits were incubated with bisphenol A (2,2-bis(4-hydroxyphenyl)propane, BPA) at 37 degrees C, BPA was oxidized by crude enzymes from potato, eggplant, and lettuce. The crude enzyme prepared from potato (Solanum tuberosum) had the strongest oxidative activity for BPA. Its optimal temperature and pH were 40-45 degrees C and 8.0, respectively. More than 95% of BPA was oxidized after the incubation with potato enzyme for 60 min. BPA gave two oxidation products besides insoluble compounds during the oxidation by potato enzyme. The oxidation products were identified to be 4[1-(4-hydroxyphenyl)-1-methyl-ethyl]-benzene-1,2-diol and 4[1-(4-hydroxyphenyl)-1-methyl-ethyl]-benzene-1,3-diol. Enzymatically oxidized BPA lost the estrogen-like activity to enhance the growth of human breast cancer (MCF-7) cells.     

Determination of bisphenol A in canned foods by immunoaffinity chromatography, HPLC, and fluorescence detection

Bisphenol A (BPA) concentrations were determined in canned beverages, fruits, vegetables, and fat-containing foodstuffs bought in Austrian supermarkets. The analysis method consisted of sol-gel immunoaffinity chromatography followed by high-performance liquid chromatography with fluorescence detection. With one exception traces of BPA were detected in all samples. BPA recovery strongly depended on the food matrix, ranging from 27% in goulash to 103% in a lemon soft drink. The results obtained allow a more realistic picture of the BPA exposure caused by cans with an epoxy resin protective coating because--in contrast to several previous studies--only those fractions of the can contents that are actually consumed were analyzed. BPA concentrations ranging from 0.1 ng/mL (lemon soft drink) to 38 ng/g (ready-to eat soup from Thailand) were significantly lower than the European Union migration limit of 0.6 mg of BPA/kg of food.     

Separation and Determination of Three Phenolic Xenoestrogens in Industrial Wastewater by Micellar Electrokinetic Chromatography on Polydimethylsiloxane Microchip

The separation on microchip provides the advantages including high efficiency, increased throughput, reduced quantities of hazardous materials, cost saving, relatively facile instrumentation, improved portability, etc. A technique of micellar electrokinetic chromatography (MEKC) coupled with amperometric detection has been actualized on a polydimethylsiloxane microchip for the rapid separation and determination of three phenolic xenoestrogens as octylphenol (OP), 4-nonylphenol (4-NP), and bisphenol A (BPA). The baseline separation of these phenolic xenoestrogens is successfully obtained within 55?s under the optimized MEKC conditions with borate running buffer of pH?8.0 containing sodium dodecyl sulfate and ??-cyclodextrin. The linear range for OP, 4-NP, and BPA are 20?C1,000, 15?C1,000, and 20?C1,000???g/L with the detection limit of 5.0, 4.0, and 3.0???g/L, respectively. The present method is successfully applied for the determination of these phenolic xenoestrogens in some industrial wastewater samples from mainland of China with the recoveries ranged from 90.2 to 109.4?%.     

Bisphenol A Adsorption Onto Metals Oxides and Organic Materials in the Natural Surface Coatings Samples (NSCSs) and Surficial Sediments (SSs): Inhibition for the Importance of Mn Oxides

Selective extraction techniques followed by batch adsorption experiments and statistical analyses were employed to investigate the adsorption behavior of bisphenol A (BPA) onto the natural surface coatings samples (NSCSs) and surficial sediments (SSs) and estimate the relative contribution of components (i.e. Fe oxides, Mn oxides, organic materials and residues) to the total BPA adsorption. The results indicate that nonlinear Langmuir model can describe the adsorption behavior of BPA on the NSCSs and SSs before and after extraction treatments. The removal of Mn oxides from the NSCSs and SSs caused a significant increase in BPA adsorption, which implied that Mn oxides inhibited BPA adsorption onto solid matrix, and Fe oxides played a positive role in BPA adsorption onto the NSCSs and SSs. However, the removal of organic materials (OMs) led to a dramatic decrease in BPA adsorption, suggesting considerable amounts of BPA adsorbed onto OMs in the NSCSs and SSs. This study may provide important insights into the understanding of the transport and ultimate fate of BPA in the aquatic environments.     

Concentrations of bisphenol a, bisphenol a diglycidyl ether, and their derivatives in canned foods in Japanese markets

Bisphenol A (BPA), bisphenol A diglycidyl ether (BADGE), and their derivatives in 38 canned foods sold in Japan were measured using high-performance liquid chromatography-mass spectrometry (LC-MS) and LC-tandem mass spectrometry (LC-MS/MS). BPA, BADGE, BADGE.2H 2O, BADGE.HCl.H2O, BADGE.HCl, and BADGE.2HCl were 0-235.4, 0-3.4, 0-247.2, 0.2-196.4, 0-3.0, and 0-25.7 ng/g, respectively, which did not exceed acceptable daily intake for BPA and specific migration limit for BADGEs. BADGE was degraded by 58, 100, 46, and 58% in water (pH 7), 0.01 N HCl (pH 2), 0.01 N NaCl (pH 6.8), and 0.01 N NaCl with acetic acid (pH 2.5), respectively, when it was allowed to stand at 120 degrees C for 30 min. The prominent derivatives formed were BADGE.2H 2O and BADGE.HCl.H2O, which was formed not only in BADGE with added HCl but also in that with NaCl. Acetic acid accelerated the formation of both BADGE.2H2O and BADGE.HCl.H2O in NaCl. No BPA was detected in any simulation samples started from BADGE. The results suggest that BPA and BADGE are independently leached into canned foods and that BADGE is easily changed to more stable compounds such as BADGE.2H2O and BADGE.HCl.H2O by sterilization.     

Levels of bisphenol A in canned liquid infant formula products in Canada and dietary intake estimates

A sensitive, efficient, and reproducible method, based on solid phase extraction and derivatization with acetic anhydride followed by gas chromatography-mass spectrometry in selected-ion monitoring mode, was developed for the determination of bisphenol A (BPA) in liquid infant formula. The method quantification limit was 0.5 ng g(-1). Extraction recoveries were 85-94% over the concentration range of 2.5-20 ng g(-1). Good reproducibility of the method was observed at levels of 0.54 and 10.4 ng g(-1) with relative standard deviations of 5.0 and 2.8%, respectively. The method was used to analyze samples of 21 canned liquid infant formula products for BPA. BPA was detected in all samples at levels ranging from as low as 2.27 ng g(-1) to as high as 10.2 ng g(-1). The probable daily intakes of BPA due to consumption of canned liquid infant formula were estimated for infants from premature to 12-18 months of age. The maximum probable daily intake of BPA was 1.35 microg kg(-1) of body weight day(-1) for 0-1-month-old infants with the maximum formula intake, which is below the provisional tolerable daily intake for BPA established by Health Canada, 25 microg kg(-1) of body weight day(-1).     

Determination of bisphenol a and bisphenol B residues in canned peeled tomatoes by reversed-phase liquid chromatography

Bisphenol A (BPA) and bisphenol B (BPB) concentrations were determined in peeled canned tomatoes of different brands bought in Italian supermarkets. Tomato samples analyzed were packaged in cans coated with either epoxyphenolic lacquer or low BADGE enamel. A solid phase extraction (SPE) was performed on C-18 Strata E cartridge followed by a step on Florisil cartridge. Detection and quantitation were performed by a reversed phase high-performance liquid chromatography (RP-HPLC) method with both UV and fluorescence detection (FD). On the total of 42 tested tomato samples, BPA was detected in 22 samples (52.4%), while BPB was detected in 9 samples (21.4%). BPA and BPB were simultaneously present in 8 of the analyzed samples. The levels of BPA found in this study are much lower than the European Union migration limits of 3 mg/kg food and reasonably unable to produce a daily intake exceeding the limit of 0.05 mg/kg body weight, established by European Food Safety Authority.     

Identification of a Germicidal Compound against Picornavirus in Bamboo Pyroligneous Acid

The germicidal activity of pyroligneous acid (PA) against a picornavirus, encephalomyocarditis virus (EMCV), was analyzed, and the component responsible for its disinfectant activity was identified. Bamboo PA (BPA) inactivated EMCV, but neutralization of BPA abolished this activity. Using liquid-liquid phase extraction and silica gel column chromatography, the hydrophobic active fraction of BPA was separated and its 12 major components were identified. The active fraction was reconstructed by mixing synthetic chemicals at the determined concentrations, and a subtraction series of one chemical from the complete mixture was prepared. An in vitro virus assay demonstrated that phenol was the sole germicidal component, and acetic acid augmented the phenol's inactivating activity resulting in >5-log decrease in EMCV infectivity. Considering the low environmental risk of PA, these findings suggest that BPA is a potentially useful agent for preventing viral epidemics in agricultural and human environments.     

One-step derivatization and preconcentration microextraction technique for determination of bisphenol A in beverage samples by gas chromatography-mass spectrometry

A simple technique based on ultrasound-assisted emulsification microextraction in situ derivatization (USAEME-ISD) is proposed for the one-step derivatization, extraction, and preconcentration of bisphenol A (BPA) in beverage samples prior to gas chromatography-mass spectrometry (GC-MS) analysis. BPA was in situ derivatized with acetic anhydride and simultaneously extracted and preconcentrated by using USAEME. Variables affecting the extraction efficiency of BPA were evaluated. Under optimal experimental conditions, the detection limit (LOD) was 38 ng L(-1) with a relative standard deviation (RSD) value of 11.6%. The linear working range was 100-1250 ng L(-1), and the coefficient of estimation (r(2)) of the calibration curve was ≥0.9971. The robustness of the proposed methodology was probed by developing a recovery study at two concentrations (125 and 500 ng L(-1)) over different beverage samples. This study led to a satisfactory result achieving recoveries of ≥82%, which showed acceptable robustness for determination of nanograms per liter of BPA in samples of food safety interest.     

Response Surface Methodology for Modeling Bisphenol A Removal Using Ultrafiltration Membrane System

In this work, the effects of various operating parameters (pressure, pH, BPA concentration, and filtration time) toward bisphenol A (BPA) removal via ultrafiltration (UF) membrane system were investigated using response surface methodology (RSM). Historical data design of RSM was used to obtain the interaction between variables and response as well as optimizing the process. The analysis of variance (ANOVA) showed that the third-order polynomial model was significant in which pH and filtration time were identified as significant terms that influence BPA removal. The 3D response surface plots revealed the two-factor interaction between independent and dependent variables. The optimization process of the model predicted optimum conditions of 99.61% BPA removal at 1 bar, pH 6.7, 10 μg/L BPA concentration, and 10-min filtration time. The predicted optimum conditions for BPA removal were consistent with the obtained experimental values, indicating reliable application of historical data design RSM for modeling BPA removal in UF membrane system.     

Identification of urinary and intestinal bacterial metabolites of ellagitannin geraniin in rats

Hydrolyzable tannins, including ellagitannins, occur in foods such as berries and nuts. Various biological activities, including antioxidant, antiviral, and antitumor activities, have been noted and reported for ellagitannins, but the absorption and metabolism of purified ellagitannins are poorly understood. We describe herein the characterization of urinary and intestinal microbial metabolites in rats after the ingestion of ellagitannins. Urine samples were collected after oral administration of ellagitannins such as geraniin ( 1), corilagin ( 2), and their related polyphenols. The suspension of rat intestinal microflora was anaerobically incubated with ellagitannins. Each sample was separated by column chromatography and/or preparative HPLC to give seven metabolites, M1- M7. The structures of these metabolites were determined on the basis of spectroscopic data and chemical evidence. These compounds, except for M1, were characterized as ellagitannin metabolites for the first time. Furthermore, among four major metabolites ( M1- M4) in urine, M2 showed an antioxidant activity comparable to intact geraniin and related polyphenols.     

Removal of Bisphenol A and 17β-Estradiol by Single-Walled Carbon Nanotubes in Aqueous Solution: Adsorption and Molecular Modeling

Single-walled carbon nanotubes, both before (SWNTs) and after treatment (t-SWNTs) with acidified ammonium persulfate, were successfully used to adsorb bisphenol A (BPA) and 17??-estradiol (E2) from aqueous systems. The surface characteristics of the SWNTs and t-SWNTs were analyzed by measuring their surface charge and by imaging their morphological properties through transmission electron microscopy. The extent of defects on the SWNT scaffold generated through acid etching was analyzed by Raman spectroscopy. A total of 19.4, 15.4, and 14.3?mg/g of BPA was adsorbed on SWNTs, while a total of 8.0, 6.4, and 5.1?mg/g was adsorbed on t-SWNTs with a 72-h contact time at 280, 295, and 315?K, respectively. A significantly high fraction of E2 (27.2?mg/g) was absorbed by both SWNTs and t-SWNTs, as compared to BPA. The adsorption kinetics was analyzed using a pseudo-second-order model. Sorption experiments showed that t-SWNTs adsorbed less than half as much BPA as SWNTs, but their E2 adsorption was similar. The sorption mechanism was investigated by performing molecular-level calculations. Adsorption energies calculated using density functional theory show preferential sorption of E2 to SWNTs and graphene (?26.2?kcal/mol on SWNT and ?34.1?kcal/mol on graphene) compared to BPA (?17.1?kcal/mol on SWNT and ?22.5?kcal/mol on graphene), which were consistent with the experimental findings. Thus, ab initio calculations can mechanistically explain the adsorption differences of BPA and E2 on SWNTs.     

Analysis of bisphenol A and alkylphenols in cereals by automated on-line solid-phase extraction and liquid chromatography tandem mass spectrometry

An on-line solid-phase extraction (SPE) following a liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method was established for the simultaneous analysis of bisphenol A (BPA), nonylphenol (NP), and octylphenol (OP) in cereals (including rice, maize, and wheat). The target compounds were extracted by acetonitrile, purified by an automated on-line SPE cartridge, and analyzed by LC-MS/MS under the negative-ion mode. Mean recoveries fortified at three concentration levels ranged from 81.6 to 115.7%, and the coefficient of variation ranged from 4.6 to 19.9% (n = 6). The limits of quantification (LOQs) of the method were 0.5, 0.5, and 0.25 μg/kg for BPA, NP, and OP, respectively, in both rice and maize, while the LOQs in wheat were 0.5, 1.25, and 0.5 μg/kg for BPA, NP, and OP, respectively. This method was applied in the analysis of rice, maize, and wheat from a local market. As a result, NP occurred in all cereal samples at the concentration range of 9.4-1683.6 μg/kg and BPA was detected in a few samples.     

Inhibition of extrahepatic human cytochromes P450 1A1 and 1B1 by metabolism of isoflavones found in Trifolium pratense (red clover)

Biochanin A and formononetin are the predominant isoflavones in red clover. In a previous study (J. Agric. Food Chem. 2002, 50, 4783-4790), it was demonstrated that human liver microsomes converted biochanin A and formononetin to genistein and daidzein. This paper now shows CYP1B1-catalyzed O-demethylation of biochanin A and formononetin to produce genistein and daidzein, respectively, which inhibit CYP1B1. Recombinant human CYP1A1 or CYP1B1 was incubated with biochanin A or formononetin. CYP1A1 catalyzed isoflavone 4'-O-demethylation and hydroxylations with similar efficiency, whereas CYP1B1 favored 4'-O-demethylation over hydroxylations. Three of the biochanin A metabolites (5,7,3'-trihydroxy-4'-methoxyisoflavone, 5,7,8-trihydroxy-4'-methoxyisoflavone, and 5,6,7-trihydroxy-4'-methoxyisoflavone) were characterized by 1H NMR spectroscopy and mass spectrometry. Daidzein (Ki = 3.7 microM) exhibited competitive inhibition of CYP1B1 7-ethoxyresorufin O-deethylase activity, and genistein (Ki = 1.9 microM) exhibited mixed inhibition. Biochanin A and/or formononetin may exert anticarcinogenic effects directly by acting as competitive substrates for CYP1B1 or indirectly through their metabolites daidzein and genistein, which inhibit CYP1B1.     

Effect of heat processing and storage time on migration of bisphenol A (BPA) and bisphenol A-diglycidyl ether (BADGE) to aqueous food simulant from Mexican can coatings

Effects of heat processing and storage time (up to 70 days) on migration of bisphenol A (BPA) and bisphenol A-diglycidyl ether (BADGE) from can coatings into an aqueous food simulant were determined. Distilled water was canned in two types of Mexican cans: for tuna and for jalape?o peppers. Results showed that there is an effect of heat treatment on migration of both compounds. Storage time did not show any effect in BPA migration from tuna cans. There was an effect of storage time on BPA migration from jalape?o pepper cans. Results for BADGE migration were affected by its susceptibility to hydrolyze in aqueous simulants. BADGE concentration decreased, or was not detected, during storage in both types of cans. Migration levels for BPA and BADGE were within 0.6-83.4 and <0.25-4.3 microg/kg, respectively. Both were below European and Mercosur legislation limits. Other migrating compounds were detected, although no identification was performed.     

Migration of bisphenol A from polycarbonate baby and water bottles into water under severe conditions

The isotope dilution headspace solid-phase microextraction and gas chromatography-mass spectrometry method for bisphenol A (BPA) developed previously was used successfully in a BPA migration study at 70 degrees C of polycarbonate baby and reusable water bottles recently sold in Canada by using the whole bottles instead of pieces cut from the bottles. Migration of BPA from the PC bottles heated at 70 degrees C was found to increase over the time in the quadratic equations. Migration levels of BPA in water varied from 228 to 521 microg L (-1) or from 0.26 to 0.90 microg cm (-2) after being heated at 70 degrees C for 6 days. The average migration rates of BPA from the PC bottles into water at 70 degrees C ranged from 1.84 to 4.83 ng cm (-2) h (-1).     

Migration of bisphenol A (BPA) from epoxy can coatings to jalapeño peppers and an acid food simulant

Effects of heat processing, storage time, and temperature on migration of bisphenol A (BPA) from an epoxy type can coating to an acid food simulant and jalape?o peppers were determined. Commercial jalape?o pepper cans (8 oz, dimensions 211 x 300) were stored at 25 degrees C for 40, 70, and 160 days. A solution of 3% acetic acid was canned in 211 x 300 cans from the same batch used for jalape?o peppers. Heat processing was applied to two-thirds of the cans, and the remaining cans were not heat processed. Cans were stored at 25 and 35 degrees C for 0, 40, 70, and 160 days. Results showed that there is a minimal effect of heat treatment. An effect of storage time on migration of BPA during the first 40 days at 25 degrees C was observed. An increase on migration of BPA was observed with storage time at 35 degrees C. The highest level of migration was 15.33 microg/kg of BPA at 160 days at 35 degrees C. A correction factor of approximately 0.4 was calculated for migration under simulating conditions of storage compared to the real ones. The highest level of BPA found in jalape?o peppers cans, surveyed from three supermarkets, was 5.59 +/- 2.43 microg/kg. Migration of BPA, performed according to the European and Mercosur conditions, was 65.45 +/- 5.29 microg/kg. All the migration values found in this study were below those legislation limits (3 mg/kg).     

Visible-Light-Driven Photocatalytic N-Doped TiO<Subscript>2</Subscript> for Degradation of Bisphenol A (BPA) and Reactive Black 5 (RB5) Dye

Bisphenol A (BPA) and reactive black 5 (RB5) dye are among the most persistent and non-biodegradable contaminants in water which require an urgent need for the development of effective removal method. The ubiquitous existence of both contaminants could interfere with the human health and aquatic environmental balance. Photocatalytic process as one of advanced oxidation processes (AOPs) has shown high performance for degradation of organic compounds to the harmless materials under sensible condition. Therefore, this study aims to develop a visible-light-driven photocatalyst that can efficiently degrade BPA and RB5 present in household water. N-doped TiO₂ were successfully synthesized via simple and direct sol–gel method. The prepared TiO₂ nanoparticles were characterized by field emission scanning microscope (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and Brunauere Emmette Teller (BET) analysis. The incorporation of nitrogen in TiO₂ lattice exhibited excellent optical responses to visible region as revealed by UV–Vis–NIR spectroscopy absorption capability at 400–600 nm. The photocatalytic activity of the N-doped TiO₂ nanoparticles was measured by photocatalytic degradation of BPA and RB5 in an aqueous solution under visible-light irradiations. Degradation of BPA and RB5 was 91.3% and 89.1%, respectively after 360 min illumination. The degradation of BPA and RB5 by N-doped TiO₂ was increased up to 89.8% and 88.4%, respectively under visible-light irradiation as compared to commercial TiO₂ P25. This finding clearly shows that N-doped TiO₂ exhibits excellent photocatalytic degradation of BPA and RB5 under visible irradiation, hence have a promising potential in removing various recalcitrant contaminants for water treatment to fulfill the public need to consume clean water.

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Graphical Abstract ?

     

Antioxidant properties of sour cherries (Prunus cerasus L.): role of colorless phytochemicals from the methanolic extract of ripe fruits

Many edible plant metabolites are known to be useful as cellular antioxidants. In the search for antioxidative chemicals from native fruits of the Campania region of Italy, Prunus cerasus L., an acidic cherry widely used for culinary purposes, has been studied. Fruit crude extracts (MeOH, EtOAc, and hexane) were submitted to an antioxidative screening using specific assay media characterized from the presence of highly reactive radical species (DPPH*, ABTS*+, O2*-, NO) or lipoperoxidation markers. The reducing power of the samples was also determined. It was observed that the most polar extracts in MeOH and EtOAc were able to exercise a massive and dose-increasing antioxidative capacity. The peculiar efficacy of the same extracts was revealed by investigating their protein and deoxyribose oxidation capacity. A preliminary analysis of total phenol, flavonoid, and anthocyanin contents together with biological screening data put the basis on P. cerasus fruit phytochemical investigation of methanolic extract. Twenty secondary metabolites were isolated and characterized by spectroscopic (especially 1D and 2D NMR) and spectrometric techniques. 1-(4-Hydroxyphenyl)-1,2-ethanediol-1,2-bis-1-O-beta-D-glucopyranoside (3), (4-hydroxy-3-methoxyphenyl)methanol-1-O-beta-D-gentiobioside (4), epicatechin-3-malate (14), and epicatechin-3-(1'-methyl)malate (15) were isolated for the first time. All of the compounds were evaluated for their radical scavenging activity on DPPH*, O2*-, and NO. Flavonoids and quinic acid derivatives were found to be the more antioxidative substances.     

Simultaneous determination of bisphenol A and its halogenated analogues in soil by fluorescence polarization assay

Purpose

Extensive use of bisphenol A (BPA) and its analogues has caused increasing concern over the potential adverse health impacts of these chemicals. The aim of this study was to develop a fluorescence polarization (FP) assay to detect bisphenol A, bisphenol AF (BPAF), tetrabromobisphenol A (TBBPA), and tetrachlorobisphenol A (TCBPA) simultaneously.

Materials and methods

A recombinant peroxisome proliferator-activated receptor α ligand binding domain (mPPARα-LBD*) was chosen as recognition element in developed FP procedure. The environmental soil samples were assayed for (1) analytical parameters, (2) matrix effect, (3) recovery experiment, and (4) HPLC validation. For statistical analysis, GraphPad Prism 5 software was used.

Results and discussion

Under the optimized conditions, this assay had an IC₅₀ of 2.80, 6.84, 4.67, and 4.66 μg g^?1 for BPA, BPAF, TBBPA, and TCBPA, respectively. The developed assay demonstrated the limits of detection (LODs) of 0.35, 0.21, 0.27, and 1.03 μg g^?1 for these four compounds, which could meet the requirement of environmental monitoring. For spiked soil samples, mean recoveries of the analytes ranged from 85.3 to 101.1%, yielding coefficient of variations (CVs) ranged from 9.8 to 17.5%.

Conclusions

In this study, a broad-specificity receptor protein for BPA, BPAF, TBBPA, and TCBPA was produced and was used to develop an FP assay in soil samples. The efficiency and simplicity of the proposed assay define its possible application as a screening tool for environmental monitoring.