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At least 775 records · Page 43Linked to original sources
PubMed2005

Medium composition affects the degree and pattern of cadmium inhibition of naphthalene biodegradation.

Metals have been reported to inhibit organic pollutant biodegradation; however, widely varying degrees and patterns of inhibition have been reported. To investigate the roles of medium composition and metal bioavailability on these different degrees and patterns of inhibition, we assessed the impact of cadmium on naphthalene biodegradation by a newly isolated strain of Comamonas testosteroni in three chemically-defined minimal salts media (MSM): Tris-buffered MSM, PIPES-buffered MSM, and Bushnell-Haas medium. Cadmium (total concentrations of 100 and 500 microM) inhibited biodegradation in each medium. Degrees of inhibition were different in each medium. Cadmium was most inhibitory in PIPES-buffered MSM and least inhibitory in Bushnell-Haas. For example, in Bushnell-Haas medium, 100 microM cadmium reduced the cell yield more than 4-fold compared to controls not containing cadmium. The same concentration of cadmium completely inhibited growth in PIPES-buffered MSM. No difference in inhibition was observed in any medium when cadmium was added 24 h before inoculation rather than when added within one minute of inoculation. Two patterns of inhibition were observed. Inhibition occurred in a dose dependent pattern in Tris- and PIPES-buffered MSM and in a non-dose dependent pattern in Bushnell-Haas. Specifically, in Bushnell-Haas, 100 microM total cadmium extended the lag phase by 23+/-8.66 h, whereas 500 microM did not extend the lag phase. Soluble, ionic cadmium (Cd2+) concentrations were measured and modeled in each medium to assess cadmium bioavailability. In media containing 500 microM total cadmium, bioavailability was highest in Tris- and PIPES-buffered MSM and lowest in Bushnell-Haas. In Bushnell-Haas, cadmium bioavailability was initially higher in the 500 microM treatments (196+/-21.2 microM) than in the 100 microM treatments (78.2+/-2.04 microM); however, after 12 h, bioavailability was higher in the 100 microM treatments (56.4+/-24.8 micro) than the 500 microM treatments (13.3+/-1.2 microM). These data suggest that the type of medium determines the degrees and patterns by which metals inhibit biodegradation and emphasize the importance of coupling metal toxicity and bioavailability data.

Biodegradation, Environmental↗
PubMed2005

Dechlorination of polychlorinated organic compounds by electrochemical reduction with naphthalene radical anion as mediator.

Electrochemical reduction with electrochemically generated naphthalene radical anion in N,N-dimethylformamide was applied to the dechlorination of five representative POPs, namely HCB, lindane, DDT, PCP and aldrin. Rapid and complete dechlorination was possible for lindane and DDT to give nearly quantitative yields of benzene and 1,1-diphenylethane, respectively. HCB was reduced through complex reaction pathways to yield unknown products. Dechlorination of PCP and aldrin beyond dichlorinated compounds was difficult because of their very negative reduction potential. The reaction pathways for each dechlorination were proposed with the identification of intermediates.

Chromatography, High Pressure Liquid↗
PubMed2006

Molecular evidence for benzo[a]pyrene and naphthalene genotoxicity in Trifolium repens L.

Polycyclic aromatic hydrocarbons (PAHs) are among the most dangerous environmental contaminants due to their toxic, carcinogenic and mutagenic effects. Although there are many data in literature that detail the effects of PAHs on animals, little is known about their action on higher plants which are often used as bioindicators. The aim of the present study was to evaluate the genotoxicity of two different PAHs, benzo[a]pyrene (BaP) and naphthalene (Naph), on Trifolium repens L. Clover plants were exposed to soil which had been artificially contaminated with three concentrations of BaP (5, 10 and 20 microg g-1) or Naph (25, 50 and 100 microg g-1). After 15 days, changes in the DNA content and sequence of roots and shoots were evaluated by flow cytometry (FCM) and amplified fragment length polymorphism (AFLP). Root and shoot dry weight were also determined to assess plant growth. Results showed that BaP and Naph were both genotoxic for white clover, inducing significant changes in root and shoot DNA sequence. Damage was more severe in the root than in the shoot suggesting that the translocation of these compounds and their genotoxic metabolites was limited. Ploidy alterations were not detected and the extent of damage caused by all the tested PAH concentrations was not sufficient to affect plant development.

Base Sequence↗
PubMed2007

Polychlorinated biphenyls and -naphthalenes in pine needles and soil from Poland--concentrations and patterns in view of long-term environmental monitoring.

Pine needles were selected as cost effective and easy collectable matrices suitable for long-term monitoring of the lower troposphere pollution with polychlorinated biphenyls and polychlorinated naphthalenes. The fingerprints of PCNs and PCBs in the top layers of agricultural soils were used for determination of point sources of pollution for terrestrial ecosystems. The new idea based on the use of nona- and decachlorinated isomers fingerprint as an additional tool suitable for the identification of potential point sources of pollution with PCBs, seemed to be a capable tool to identify contamination of soil and ambient air related to former manufacturing and the use of highly chlorinated technical PCB preparations.

Air↗
PubMed2006

Human exposure to polychlorinated naphthalenes through the consumption of edible marine species.

The concentrations of polychlorinated naphthalenes (PCNs) were determined in samples of 14 edible marine species (sardine, tuna, anchovy, mackerel, swordfish, salmon, hake, red mullet, sole, cuttlefish, squid, clam, mussel and shrimp), which are widely consumed by the population of Catalonia, Spain. The daily intake of PCNs associated with this consumption was also determined. A total of 42 composite samples were analyzed by HRGC/HRMS. The highest PCN levels (ng/kg of fresh weight) were found in salmon (227) followed by mackerel (95) and red mullet (68), while the lowest levels of total PCNs corresponded to shrimp (4.9) and cuttlefish (2.7). With the exception of cephalopods and shellfish species, in which tetra-CN was the predominant homologue, penta-CN (60%) was the predominant contributor to total PCNs. For a standard male adult, PCN intake through the consumption of edible marine species was 1.53 ng/day. The highest contributions to this intake (ng/day) corresponded to salmon (0.41), sole (0.28) and tuna (0.24). Concerning health risks, species-specific TEFs such as those reported by WHO and NATO for PCDD/Fs and dioxin-like PCBs are not currently available for PCN congeners. Although in general terms the results of the present study do not seem to suggest specific risks derived from exposure to PCNs through fish and seafood consumption, to establish the contribution of individual PCN congeners to total TEQ is clearly necessary for the assessment of human health risks.

Adolescent↗
PubMed2007

Polychlorinated naphthalenes and coplanar polychlorinated biphenyls in tissues of harbor seals (Phoca vitulina) from the northern Gulf of Alaska.

Blubber, liver and kidney samples of harbor seals (Phoca vitulina) from the northern Gulf of Alaska were collected during 2000-2001 for the analysis of polychlorinated naphthalenes (PCNs) and coplanar polychlorinated biphenyls (CoplPCBs). On the lipid weight (lw) base, the total concentrations of PCNs (Sigma PCNs) ranged from 0.3 to 27 ng/g lw, and the total concentrations of CoplPCBs (Sigma CoplPCBs) were 3.6-546 ng/g lw in all the tissue samples. Di-ortho PCBs and mono-ortho PCBs were dominant followed by non-ortho PCBs and PCNs. Sigma Mono-ortho PCBs and Sigma di-ortho PCBs in nursing seals were apparently lower than those in male adult seals, but Sigma PCNs and Sigma non-ortho PCBs in female adults were not significantly different from those in male adults. Differences in PCNs and CoplPCBs congener profiles in female and male adult seals are apparently related to their chemical structure and properties, animal's developmental stages and physiological conditions. A large quantity of mono-ortho and di-ortho PCBs might be transferred to newborns from the nursing seals during lactation, while non-ortho PCBs and PCNs were relatively accumulative in the mother seals. Sigma PCNs and Sigma CoplPCBs in the harbor seals correlated with ages, gender, body weight and blubber thickness, but the blubber Sigma PCNs and Sigma CoplPCBs in Kodiak Island and Southern Alaska Peninsula (KIAP) did not significantly differ from those in Prince William Sound (PWS). In addition to the new PCB data, this first report on PCN contamination in Alaskan harbor seal tissues is useful for the wildlife and ecosystem management and human health protection.

Adipose Tissue↗
PubMed2004

Enantiomeric separation of naphthalene-2,3-dicarboxaldehyde derivatized DL-3,4-dihydroxyphenylalanine and optical purity analysis of L-3,4-dihydroxyphenylalanine drug by cyclodextrin-modified micellar electrokinetic chromatography.

A new cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method for the enantiomeric separation of 3,4-dihydroxyphenylalanine (DOPA), derivatized with naphthalene-2,3-dicarboxaldehyde (NDA) to produce cyanobenzoisoindole (CBI) derivative, has been developed. The unsubstituted alpha-, beta-, gamma-cyclodextrins (CDs) and hydroxypropyl-substituted alpha-, beta-, gamma-CDs, as chiral selector, were examined for the enantiomeric separation of CBI-DL-DOPA. In addition to the concentration of chiral selector, some other experimental factors also have been optimized, such as concentration of borate buffer, content of sodium dodecyl sulphate (SDS), pH of electrolyte and applied voltage. Optimal separation was obtained at pH 8.0, 100 mM borate solution containing 5 mM HP-gamma-CD and 120 mM SDS, as well as 18 kV applied voltage and 25 degrees C capillary temperature. Detection was followed by direct UV absorptiometric measurements at 254 nm. The developed method was employed for optical purity analysis of levodopa drug and allowed the determination of 0.14% D-DOPA in L-3,4-dihydroxyphenylalanine (levodopa) with well peak identification.

Buffers↗
PubMed2005

Comparative study on the use of ortho-phthalaldehyde, naphthalene-2,3-dicarboxaldehyde and anthracene-2,3-dicarboxaldehyde reagents for alpha-amino acids followed by the enantiomer separation of the formed isoindolin-1-one derivatives using quinine-type chiral stationary phases.

Cinchona alkaloid based chiral stationary phases (CSPs) were evaluated and compared for the enantiomer separation of a set of alpha-amino acid derivatives as selectands (SA), using ortho-phthalaldehyde (OPA), naphthalene-2,3-dicarboxaldehyde (NDA) and anthracene-2,3-dicarboxaldehyde (ADA) as reagents in the presence of acetonitrile. Protocols have been developed for the derivatization of most common amino acids in the absence of the usual thiol components (2-mercaptoethanol, mercaptosulphonic acid, sodium sulfite) under acidic and neutral conditions providing the corresponding isoindolin-1-one (phthalimidine) derivatives. They are stable for hours at various reaction conditions compared to thiol or sulfide modified isoindoles resulted by the OPA-thiol reaction type. Among the derivatizing agents, ADA afforded the highest retention factors (k) and for the majority of the analytes also resolution (Rs) and enantioselectivity (alpha) values (i.e. for tryptophan k1 = 23, Rs = 4.93 and alpha = 1.43). Structure variation of the CSPs and selector (SO), respectively indicates that steric arrangement around the binding cleft plays a major role in the enantiodiscriminating events. To provide more detailed information about the derivatization reaction itself, the proposed mechanism for the formation of the OPA derivative (isoindolin-l-one) was further evaluated by deuterium labeling and LC-MS analysis.

Amino Acids↗
PubMed2006

Fluctuations of biochemical constituents and marker enzymes as a consequence of naphthalene toxicity in the edible estuarine crab Scylla serrata.

The sublethal effects of naphthalene on protein, deoxyribonucleic acid (DNA), ribonucleic acid (RNA), carbohydrates, lipids, and certain marker enzymes such as phosphatases, transaminases, and lactate dehydrogenase were studied in hepatopancreas, hemolymph, and ovary in the edible crab Scylla serrata. The results revealed that there was overall decrease in total protein, total DNA, total RNA, free sugar, glycogen, protein-bound sugars, neutral lipid, glycolipid, and phospholipid in the test samples compared to control. Similarly all the marker enzymes (acid phosphatase, alkaline phosphatase, aspartate transaminase, alanine transaminase, and lactate dehydrogenase) were decreased in hepatopancreas and ovary. On the other hand, in hemolymph, the activities of marker enzymes were increased. The results were tested statistically and interpreted accordingly.

Animals↗
PubMed2005

Polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, naphthalenes and polybrominated diphenyl ethers in the edible fish caught from the Baltic Sea and lakes in Finland.

A total of 156 fish composite samples were collected from five areas of the Baltic Sea and from three lakes and analysed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and polybrominated diphenyl ethers (PBDEs). The European Union's maximum permissible level for PCDD/Fs, 4 pg WHO-TEQ/g fresh weight (fw), was exceeded in salmon, river lamprey and Baltic herring. In other species from the Baltic Sea, the 90th percentile was 3.42 pg WHO(PCDD/F)-TEQ/g fw. In the lake fish, the concentrations of PCDD/Fs, PCBs and PCNs were only 29-46% of those in the same species caught from the Baltic Sea, whereas the concentrations of PBDEs in the lake fish were as high as in the Baltic Sea fish. Dioxin-like PCBs contributed to the total dioxin-like toxicity of PCBs and PCDD/Fs by 49+/-12% in all the analysed samples.

Animals↗
PubMed2005

The haloperoxidase of the agaric fungus Agrocybe aegerita hydroxylates toluene and naphthalene.

The mushroom Agrocybe aegerita secretes a peroxidase (AaP) that catalyzes halogenations and hydroxylations. Phenol was brominated to 2- and 4-bromophenol (ratio 1:4) and chlorinated to a lesser extent to 2-chlorophenol. The purified enzyme was found to oxidize toluene via benzyl alcohol and benzaldehyde into benzoic acid. A second fraction of toluene was hydroxylated to give p-cresol as well as o-cresol and methyl-p-benzoquinone. The UV-Vis absorption spectrum of purified AaP showed high similarity to a resting state cytochrome P450 with the Soret band at 420 nm and additional maxima at 278, 358, 541 and 571 nm; the AaP CO-complex had a distinct absorption maximum at 445 nm that is characteristic for heme-thiolate proteins. AaP regioselectively hydroxylated naphthalene to 1-naphthol and traces of 2-naphthol (ratio 36:1). H2O2 was necessarily required for AaP function and hence the hydroxylations catalyzed by AaP can be designated as peroxygenation and the enzyme as an extracellular peroxygenase.

Agaricales↗
PubMed2003

Growing cannabis with naphthalene in Rome.

A young Italian male was investigated for possession of illicit marijuana in Rome. In his house, police found 80 cannabis plants, the plants were different sizes and located in a room with ultraviolet light, naphthalene, as a grey-white powder, was also found in his house. The man indicated that he used it for cannabis cultivation.

Cannabinoids↗
PubMed2004

Surfactant activity of a naphthalene degrading Bacillus pumilus strain isolated from oil sludge.

We studied the growth, biosurfactant activities and petroleum hydrocarbon compounds utilisation of strain 28-11 isolated from a solid waste oil. The isolate was identified as Bacillus pumilus. It grew well in the presence of 0.1% (w/v) of crude oil and naphthalene under aerobic conditions and utilised these substances as carbon and energy source. The capacity of strain 28-11 to emulsify crude oil and its ability to remove hydrocarbons looks promising for its application in environmental technologies.

Bacillus↗
PubMed2005

Assessment of in situ cellular glutathione labeling with naphthalene-2,3-dicarboxaldehyde using high-performance liquid chromatography.

We have presently studied a dialdehydic reagent, i.e. naphthalene-2,3-dicarboxaldehyde (NDA), as a fluorogenic probe for the labeling of intracellular reduced glutathione (GSH), using a yeast strain Candida albicans as a cell model. Chemical reactivity of NDA with both amino and sulfhydryl groups of the GSH molecule leads to a highly selective detection. Moreover, fluorescence properties of the resulting adduct fit well with most of modern instruments adapted for in situ measurements, and equipped with an argon laser. After incubation of cells with 100 microM of NDA for 20 min, cells were harvested and corresponding lysates obtained after a freezing cycle, were suspended in 0.2M borate buffer pH 9.2 and analysed with HPLC (column: Spherisorb ODS-2 (125 mm x 4.6 mm i.d.) 5 microm; mobile phase: methanol-0.01 M phosphate buffer pH 6.5 (20:80, v/v) at a flow rate of 0.8 mL min(-1); spectrofluorimetric detection: lambda(exc)=430 nm and lambda(em)=530 nm). The GSH-NDA adduct was identified in the yeast strain extracts using the reported HPLC technique and quantified versus a calibration curve of NDA derivatized with an excess of GSH (linearity range: 9-230 nM). The cell loading step of the free probe NDA and the extraction efficiency of the resulting NDA-GSH adduct were optimized.

Candida albicans↗
PubMed2004

In vivo monitoring of amino acids by microdialysis sampling with on-line derivatization by naphthalene-2,3-dicarboxyaldehyde and rapid micellar electrokinetic capillary chromatography.

An analytical method was developed to monitor amino acids collected by in vivo microdialysis. Microdialysate was continuously derivatized on-line by mixing 6 mM naphthalene-2,3-dicarboxyaldehyde (NDA) and 10 mM potassium cyanide with the dialysate stream in a fused silica capillary to form fluorescent products. Reaction time, determined by the flow rate and volume of reaction capillary, was 3 min. Derivatized amino acids were continuously delivered into a flow-gated interface and periodically injected onto a capillary electrophoresis unit equipped with a laser-induced fluorescence detection based on a commercial microscope. Separation was performed in the micellar electrokinetic chromatography mode using 30 mM sodium dodecyl sulfate in 15 mM phosphate buffer at pH 8.0 as the separation media. An electric field of 1.3 kV/cm was applied across a 10 cm long, 10 microm internal diameter separation capillary. These conditions allowed 17 amino acid derivatives to be resolved in less than 30 s. On-line injections could be performed at 30 s intervals for in vivo samples. Detection limits were from 10 to 30 nM for the amino acids. The method was applied to monitor the acute ethanol-induced amino acid level changes in freely moving rats. The results demonstrate the utility of the method to reveal dynamics of amino acid concentration in vivo.

Amino Acids↗
PubMed2006

A microchip electrophoresis device with on-line microdialysis sampling and on-chip sample derivatization by naphthalene 2,3-dicarboxaldehyde/2-mercaptoethanol for amino acid and peptide analysis.

The integration of rapid on-chip sample derivatization employing naphthalene 2,3-dicarboxaldehyde and 2-mercaptoethanol (NDA/2ME) with an easily assembled microdialysis/microchip electrophoresis device was carried out. The microchip device consisted of a glass layer with etched microfluidic channels that was sealed with a layer of poly(dimethylsiloxane) (PDMS) via plasma oxidation. This simple sealing procedure alleviated the need for glass thermal bonding and allowed the device to be re-sealed in the event of blockages within the channels. The device was used for analysis of a mixture of amino acids and peptides derivatized on-chip with NDA/2ME for laser-induced fluorescence (LIF) detection. A 0.6 mM NDA/1.2 mM 2ME mixture was simply added into the buffer reservoir for dynamic on-column derivatization of sample mixtures introduced at a flow rate of 1.0 microl/min. Using this scheme, sample injection plugs were derivatized and separated simultaneously. Injections of ca. 12 fmol of 5 mM amino acid and peptide samples were conducted using the system. Finally, a three-component mixture of Arg, Gly-Pro, and Asp was sampled from a vial using microdialysis, derivatized, separated and detected with the system. The ultimate goal of this effort is the creation of a micro-total analysis system for high-temporal resolution monitoring of primary amines in biological systems.

Amino Acids↗
PubMed2004

Sublethal effect of naphthalene on lipid peroxidation and antioxidant status in the edible marine crab Scylla serrata.

The effect of naphthalene on lipid peroxidation and antioxidants status was studied in hepatopancreas, haemolymph and ovary of the Scylla serrata with reference to the active vitellogenic stage. There was an overall increase in lipid peroxidation activity in the tested samples. In contrast, the enzymatic (catalase, glutathione peroxidase, superoxide dismutase) and non-enzymatic antioxidants (vitamins C, E and glutathione) showed decreased activities for hepatopancreas, haemolymph and ovary.

Animals↗
PubMed2005

Radiative electronic energy transfer-time studies of naphthalene-biacetyl system by one and two-photon excitation, and optical antenna mechanism.

In principle, the optical energy absorbed by a complex molecule raises that molecule to one of its excited states, and afterwards this excitation energy decays through the relaxation channels. Initially, electronically excited naphthalene emits photons and these emitted photons are absorbed by the acceptor molecule biacetyl, then excited biacetyl fluoresces. In this investigation radiative energy transfer-time is measured in cyclohexane by one and two-photon excitations. The UV-vis spectrum of biacetyl vapor at room temperature conditions was broad and structureless.

Cyclohexanes↗