Search results for "polycyclic aromatic hydrocarbon"
showing 10 items of 138 documents
The impact of lactic acid bacteria with antimicrobial properties on biodegradation of polycyclic aromatic hydrocarbons and biogenic amines in cold sm…
2017
The influence of surface treatment with lactic acid bacteria (LAB), previously cultivated in an alternative substrate, on the formation of polycyclic aromatic hydrocarbons (PAHs) and biogenic amines (BAs) in cold smoked pork meat sausages was investigated. Moreover, sausages treatment with LAB after the smoking on PAHs content changes was evaluated. Additionally, the inhibitory effects of LAB metabolites on food spoilage bacteria was determined using the agar well diffusion assay method. The metabolites of Pediococcus acidilactici KTU05-7, Pediococcus pentosaceus KTU05-9 and Lactobacillus sakei KTU05-6 strains showed good inhibitory properties against tested pathogenic and food spoilage bac…
Patterns of Carbon-Bound Exogenous Compounds in Patients with Lung Cancer and Association with Disease Pathophysiology.
2021
Abstract Asymptomatic anthracosis is the accumulation of black carbon particles in adult human lungs. It is a common occurrence, but the pathophysiologic significance of anthracosis is debatable. Using in situ high mass resolution matrix-assisted laser desorption/ionization (MALDI) fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry imaging analysis, we discovered noxious carbon-bound exogenous compounds, such as polycyclic aromatic hydrocarbons (PAH), tobacco-specific nitrosamines, or aromatic amines, in a series of 330 patients with lung cancer in highly variable and unique patterns. The characteristic nature of carbon-bound exogenous compounds had a strong association wi…
Tumor-initiating activity of the (+)-(S,S)- and (−)-(R,R)-enantiomers of trans-11,12-dihydroxy-11,12-dihydrodibenzo[a,l]pyrene in mouse skin
1999
Abstract A single administration of enantiomerically pure 11,12-dihydrodiols of dibenzo[ a,l ]pyrene (DB[ a,l ]P) on the back of NMRI mice and subsequent chronic treatment with 12- O -tetradecanoylphorbol 13-acetate (TPA) (initiation/promotion assay) revealed strikingly different carcinogenic activities of both enantiomers. Tumor-initiating activity of (−)-(11 R ,12 R )-DB[ a,l ]P-dihydrodiol, which is the metabolic precursor of the (−)- anti -(11 R ,12 S )-dihydrodiol (13 S ,14 R )-epoxide, was exceptionally higher than the corresponding effect of (+)-(11 S ,12 S )-DB[ a,l ]P-dihydrodiol, the metabolic precursor of (+)- syn -(11 S ,12 R )-dihydrodiol (13 S ,14 R )-epoxide. After topical ap…
Detoxification of optically active bay- and fjord-region polycyclic aromatic hydrocarbon dihydrodiol epoxides by human glutathione transferase P1-1 e…
1998
Dihydrodiol epoxides (DEs) are important carcinogenic metabolites of polycyclic aromatic hydrocarbons (PAHs). The metabolic formation of four stereoisomeric DEs (a pair of optically active diastereomers termed as syn- and anti-form) is possible. Glutathione tranferases (GSTs) have been demonstrated to catalyze the detoxification of DEs. Purified GSTs display remarkable differences in catalytic efficiencies towards bay- and fjord-region DEs along with a high degree of regio- and stereoselectivity. Here we determined to which extent heterologously expressed human GSTP1-1, a major GST isoform in lung, affects the mutagenicity of stereoisomeric bay-region DEs of benzo[a]pyrene in Chinese hamste…
Polycyclic aromatic hydrocarbons (PAHs) in coffee brew samples: analytical method by GC-MS, profile, levels and sources.
2009
Roasting is a crucial step for the production of coffee, as it enables the development of color, aroma, and flavor, which are essential for the characterization of the coffee quality. At the same time, roasting may lead to the formation of not desirable compounds, such as polycyclic aromatic hydrocarbons (PAHs). In this paper, we report a method for PAHs determination in coffee brew, based on saponification and liquid-liquid extraction with small volumes of hexane, with exclusion of further processes of purification since we analyze the extract by gas chromatography with mass spectrometric detectors in the single ion monitoring mode (SIM). The total concentration of the 28 compounds investi…
Application of Dopant-Assisted Atmospheric Pressure Photoionisation HPLC–MS Method for the Sensitive Determination of Polycyclic Aromatic Hydrocarbon…
2017
Multiple food research studies have shown that the polycyclic aromatic hydrocarbon (PAHs) are frequently found in processed cocoa products and chocolate. In a present study a method based on dopant-assisted atmospheric pressure photoionisation (DA-APPI) combined with a liquid chromatography/high-resolution mass spectrometer (HPLC-HRMS) for high-sensitivity analysis of four EU marker PAHs in dark chocolate samples was developed and fully validated according to the performance criteria set in EU guidelines. PAHs detection was achieved by HRMS in positive electrospray ionization mode with toluene used as a dopant to enhance the ionization efficiency of non-polar PAHs. The on-column instrument …
Efficacy of Ozonation Treatments of Smoked Fish for Reducing Its Benzo[a]pyrene Concentration and Toxicity
2017
Ozone is widely used in food processing, for example, to decompose mycotoxins or pesticide residues, to extend the shelf life of products, and for sanitation. The objective of this study was to assess the possibility of expanding the application of ozone for oxidative degradation of polycyclic aromatic hydrocarbons (PAHs). The evaluation was conducted by ozonation of a benzo[a]pyrene (BaP) standard solution and smoked fish (sprats) contaminated with PAHs. The effect of ozonation was immediate in the BaP solution; 89% of this toxic compound was decomposed after only 1 min of treatment. However, the impact of ozonation on the smoked sprats was less pronounced, even after prolonged treatment. …
Extraction of polycyclic aromatic hydrocarbons from cookies: a comparative study of ultrasound and microwave-assisted procedures.
2008
The chromatographic determination of 15 polycyclic aromatic hydrocarbons (PAHs) in cookies has been improved in order to obtain a fast method with a low limit of detection through the combination of microwave-assisted extraction (MAE), oil saponification and solid-phase extraction clean-up before the injection of purified extracts in a C18 201TP52 (5 microm, 250 x 2.1 mm) column. Using acetonitrile-water as mobile phase, with a 50% to 95% w/w acetonitrile gradient for a fixed flow of 0.250 ml min(-1), 15 PAHs were separated in 45 min. The column temperature was maintained at 15 degrees C; and fluorimetric detection was made at a fixed excitation wavelength of 264 nm and emission measurement…
Covalent DNA adducts formed by benzo[c]chrysene in mouse epidermis and by benzo[c]chrysene fjord-region diol epoxides reacted with DNA and polynucleo…
1997
The metabolic activation in mouse skin of benzo[c]chrysene (B[c]C), a weakly carcinogenic polycyclic aromatic hydrocarbon (PAH) present in coal tar and crude oil, was investigated. Male Parkes mice were treated topically with 0.5 mumol of B[c]C, and DNA was isolated from the treated areas of skin at various times after treatment and analyzed by 32P-postlabeling. Seven adduct spots were detected, at a maximum level of 0.89 fmol of adducts/microgram of DNA. Four B[c]C-DNA adducts persisted in skin for at least 3 weeks. Treatment of mice with 0.5 mumol of the optically pure putative proximate carcinogens (+)- and (-)-trans-benzo[c]chrysene-9,10-dihydrodiols [(+)- and (-)-B[c]C-diols] led to th…
Glutathione Transferase A1-1 Catalyzed Conjugation of Polycyclic Aromatic Hydrocarbon Diol-Epoxides with Glutathione
1996
Abstract The glutathione transferase A1-1 (GSTA1-1) isoenzyme catalyzes the formation of GSH-conjugates of the isomeric bay-region diol-epoxides (DEs) of trans-1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydrochrysene (CDE) and trans-3,4-dihydroxy-1,2-epoxy-1,2,3,4-tetrahydrodibenz[a,h]anthracene (DBADE) as well as the isomeric fjord-region DEs trans-3,4-dihydroxy-1,2-epoxy-1,2,3,4-tetrahydrobenzo[c]phenanthrene (BPhDE) and trans-9,10-dihydroxy-11,12-epoxy-9,10,11,12-tetrahydro-benzo[c]chrysene (BCDE) although with an approx. 20-fold variation in catalytic efficiency. With the anti-diastereomers and the syn-diastereomers of BPhDE and BCDE, GSTA1-1 demonstrated a significant preference for the enan…