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PubMed1981

Structural gene products of the murine Ah complex. Differences in ontogenesis and glucosamine incorporation between liver microsomal cytochromes P1-450 and P-448 induced by polycyclic aromatic compounds.

Antibodies against mouse-liver microsomal cytochromes P1-450 and P-448, two polycyclic aromatic inducible cytochromes, were previously developed [Negishi, M. and Nebert, D.W. (1979) J. Biol. Chem. 254, 11015-11023]. Liver microsomes from 3-methylcholanthrene-treated and phenobarbital-treated and control adult mice and 2,3,7,8-tetrachlorodibenzo-p-dioxin-treated adult and fetal mice were examined. Immunoprecipitable radioactivity was measured, following labeling with pyridoxal phosphate/NaB[3H]4 or with 125I-labeled p-aminosulfobenzoic acid/NaNO2 in vitro or with [3H]leucine, [14C]glucosamine, or [32P]O4 in vivo. (a) Induction of cytochrome P1-450 occurs developmentally earlier in gestation than induction of cytochrome P-448 when the mother is treated with polycyclic aromatic compounds. (b) There appears to be a basal form of cytochrome P-448 but no cytochrome P1-450 in control liver microsomes; inducibility of cytochrome P-448 thus ranges between 5--12-fold, whereas that of P1-450 is infinite. (c) Phenobarbital pretreatment induces no detectable P1-450 or P-448. (d) P-448 appears to be either greater in concentration than P1-450 in the membrane or more exposed than P1-450 on the microsomal membrane surface. (e) By the radioimmunoassay methods used, 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced P1-450 and P-448 in Ah-nonresponsive mice are indistinguishable from those in Ah-responsive mice; this is true in both the fetus and the adult. (f) Compared with P-448 expression, the expression of P1-450 is more closely associated with 3-methylcholanthrene-induced aryl hydrocarbon hydroxylase activity, and these two structural gene products are apparently regulated independently. (g) P-448 but not P1-450 appears to be a glycoprotein. These data illustrate further differences between two forms of polycyclic aromatic-inducible P-450 in mouse liver. Neither P1-450 nor P-448 appears to be a phosphoprotein. Neither anti-(P1-450) nor anti-(P-448) precipitates any forms of liver microsomal P-450 from beta-naphthoflavone-treated adult rabbits and, conversely, anti-LM4 (the antibody to rabbit liver microsomal P-450 form 4) does not precipitate any forms of liver microsomal P-450 from 3-methylcholanthrene-treated C57BL/6N mice.

Animals↗
PubMed2004

Interaction between halogenated aromatic compounds in the Ah receptor signal transduction pathway.

Many toxic and biochemical responses to halogenated aromatic compounds (HACs) such as polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins (PCDDs) are mediated through the aryl hydrocarbon receptor (AhR), which is an intracellular cytosolic target for HACs. Environmental exposure to HACs almost always involves complex mixtures of congeners, some of which can antagonize the action of potent HACs such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In this work we studied TCDD and representative PCB congeners, alone and in mixture, for their effect on CYP1A gene transcription and protein levels in primary rat hepatocytes. Together with our previous work, our results suggest that formation of the Ah receptor-ligand-DRE (dioxin response element) complex is the principal point of divergence in the mechanism between an AhR agonist and an AhR antagonist. The coplanar PCBs 77 and 126 and the mono-ortho PCB 156 were full agonists toward CYP1A1 gene transcription and CYP1A protein levels, showing typical additive behavior with TCDD to the target molecule AhR. In contrast, the nonplanar PCB 153 antagonized the action of TCDD, even at concentrations that occupied a significant fraction of AhR molecules. Competitive inhibition explains the commonly reported decrease of ethoxyresorufin-O-deethylase (EROD) activity when PCBs are present in high concentrations and the antagonism of PCBs to the EROD activity of TCDD. The result is that Western blotting offers a much more reliable measure of CYP1A protein concentration than does the EROD assay, despite the greater convenience of the latter.

Animals↗
PubMedDate not supplied

Electron microscopic observations concerning the action of some aromatic compounds on the morphology of Sendai virus.

The interaction between Sendai virus and some fluorescent aromatic compounds with reactive chemical groups ( a vinyl-sulfonic and an isocyano naphthalic acid derivative) leads to alterations of the surface and inner structure of virus corpuscles. The intensity of the changes depends on the type of reactive group. No such morphological changes were induced by 1-amino-2-anthraquinone-sulfonic acid, a compound whose interaction with the virus is exclusively of physical nature.

Anthraquinones↗
PubMed1987

Antimicrobial properties of aromatic compounds of plant origin.

The antimicrobial action of 11 compounds involving guaiacyl- and syringyl-like structures (low-molecular-weight part of lignin), gallic acid and its derivatives, cinnamic acid and its derivatives, veratric acid, anisic acid and crotonic acid (a total of 25 compounds) against bacteria, yeast-like organisms and protozoa was examined. Aromatic compounds modified in the C-side chain and aldehydes were effective preferentially against Trichomonas vaginalis, whereas against bacteria and yeast-like organisms eugenol was the most effective inhibitor.

Anti-Bacterial Agents↗
PubMed2003

Monitoring human occupational and environmental exposures to polycyclic aromatic compounds.

Many research groups have been carrying out studies to develop biomarkers of exposure to polycyclic aromatic compounds (PACs) and apply these for human biomonitoring. The main objectives of the use of biomarkers are to determine specific occupational and environmental exposures to monitor the effectiveness of exposure controls and prediction of the risk of disease. This article presents a review of the literature in the field of biomarkers of human exposure to PACs and an evaluation of the relevant biomarkers for monitoring exposure to PACs in a range of exposure situations from coke ovens to bitumen handling and environmental exposures. For this evaluation, the relationships between external PAC exposures and the corresponding biomarker levels have been studied. The literature data indicate that urinary excretion of 1-hydroxypyrene correlates well with external PAC exposure and this compound appears to be a suitable marker for internal exposure to PACs. DNA adducts, mostly measured in white blood cells, do not show satisfactory correlations with exposure to PACs in a variety of workplace and exposure situations. It is not clear which factors are mainly responsible for this poor correlation. Micronuclei and sister chromatid exchanges measured in peripheral white blood cells are also unsatisfactory as biomarkers for PAC exposure. From the relatively limited data available, chromosome aberrations appear to show considerable promise as indicators of exposure to PACs. Because of their strong association with cancer, chromosome aberrations are considered suitable indicators of increased cancer risk arising from exposure to PACs.

Animals↗
PubMed1986

Use of the DNA-repair host-mediated assay for determining the organ distribution of genotoxic factors in mice treated orally with nitro-aromatic compounds.

The distribution of genotoxic factors in various organs of mice treated orally with nitro-aromatic compounds of actual or potential use as chemotherapeutic (antiprotozoal and anthelminthical) agents was investigated in the DNA-repair host-mediated assay, with mice as host animals and a pair of E. coli K12 strains differing in DNA-repair capacity as indicators of genotoxicity. The test substances were derivatives of nitroimidazole (metronidazole), nitrofuran (SQ 18 506) and nitrodiphenylamine (amoscanate). Animal-mediated assays were performed by injecting mixtures of the two E. coli strains both intravenously and orally into mice, which were subsequently treated with the test chemicals, and from which the differential survival of indicator bacteria present in liver, lungs, spleen, kidneys, stomach, small intestine, colon and the blood stream was determined on selective agar medium. The same strains and selection procedures were used for assessing the genotoxic activity of the compounds in vitro. All three compounds displayed genotoxic activity in vitro, the order of potency on the basis of exposure concentration being SQ 18 506 greater than metronidazole greater than amoscanate. In the animal-mediated assays the same ranking order of genotoxic activity was observed, but the exposure levels required to produce significant genotoxic effects in vivo were (substantially) higher than in the in vitro tests: SQ 18 506 was active at 0.1 mg/kg body weight, metronidazole at 4 mg/kg, and amoscanate at dosages higher than 10 mg/kg. In host-mediated assays the highest genotoxic activity for all three chemicals was observed in organs of the gastro-intestinal tract (usually in the stomach). All three chemicals also induced genotoxic effects in organs remote from the gastro-intestinal tract although with substantially lower activity, the order of potency being again SQ 18 506 greater than metronidazole greater than amoscanate. In the case of SQ 18 506 and metronidazole, dose-dependent genotoxic activities were observed in liver, spleen, lungs, kidneys and the blood stream, with no clear indication of a preferential target or non-target organ, while the minor genotoxic effects of amoscanate were restricted to bacteria present in the blood stream. This can be taken as an indication that the substances (or active metabolites thereof) have been transported from the intestinal tract into the blood stream and distributed evenly in organ tissues, without an indication of organ specific deactivation during the time periods (less than 180 min) presently investigated.(ABSTRACT TRUNCATED AT 400 WORDS)

5-Amino-3-((5-nitro-2-furyl)vinyl)-1,2,4-oxadiazol↗
PubMed1990

Mobility of polychlorinated aromatic compounds in soils contaminated with wood-preserving oil.

Greater understanding of the mobility of polychlorinated aromatic compounds in soils is needed to investigate contamination and design suitable remediation strategies for sites contaminated with wood-preserving oil. The objectives of this study were (1) to develop a suitable aqueous batch extraction method for soil containing wood-preservative residues; (2) to determine partition coefficients for the primary contaminants [pentachlorophenol (PCP), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFS)] in oil, soil, and aqueous phases; and (3) to evaluate the potential soil migration of the primary contaminants. In a three-phase oil-soil-water mixture, PCP, PCDDs, and PCDFs were partitioned to the greatest extent in the oil phase. These results suggest that the migration of contaminants can occur in a saturated subsurface soil zone containing an oil phase at a wood-preserving site. In the absence of a free oil phase, PCDDs and PCDFs were highly partitioned onto soil and were considered non-leachable in the aqueous phase. However, PCP was considered highly leachable from contaminated soil containing only an aqueous liquid phase. Results from this study indicate that removal of any free oil phase present in subsurface soil should have highest priority during the cleanup of contaminated wood-preserving sites.

Oils↗
PubMed1987

Metabolism of aromatic compounds by Caulobacter crescentus.

Cultures of Caulobacter crescentus were found to grow on a variety of aromatic compounds. Degradation of benzoate, p-hydroxybenzoate, and phenol was found to occur via beta-ketoadipate. The induction of degradative enzymes such as benzoate 1,2-dioxygenase, the ring cleavage enzyme catechol 1,2-dioxygenase, and cis, cis-muconate lactonizing enzyme appeared similar to the control mechanism present in Pseudomonas spp. Both benzoate 1,2-dioxygenase and catechol 1,2-dioxygenase had stringent specificities, as revealed by their action toward substituted benzoates and substituted catechols, respectively.

Adipates↗
PubMedDate not supplied

Electron optic investigations on influenza virus A(H1N1) interacted with some aromatic compounds.

The morphological changes caused by the interaction of influenza virus A(H1N1) with three fluorescent aromatic compounds (a vinyl-sulfonic and an isocyano naphthalic acid derivative and the 4-acetylamino-naphthalene-1,8-dicarboxylic acid) were studied in the electron microscope. The intensity and type of the alterations depend on the chemical structure of the compounds and can be correlated with their effect on the biological activities of influenza virus.

Fluorescent Dyes↗
PubMed2006

Steroidal glycosides and aromatic compounds from Smilax riparia.

Two new steroidal glycosides named riparosides A (1) and B (2), and two aromatic compounds (3, 4), together with four known flavonoid derivatives have been isolated from the EtOH extract of the rhizomes and roots of Smilax riparia A. DC. The structure of riparoside A (1) was determined to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranosyl 3beta,20alpha-dihydroxy-5alpha-furost-22(23)-ene 26-O-beta-D-glucopyranoside. Riparoside B (2) was characterized as 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranosyl 3beta,16beta-dihydroxy-5alpha-pregnan-20-one 16-O-[5-O-beta-D-glucopyranosyl 5-hydroxy-4-methyl-pentanoic acid]-ester 26-O-beta-D-glucopyranoside. Compounds 3 and 4 were elucidated as a sucrosyl ferulic acid ester and 7-O-methyl-10-oxythymol gentiobioside, respectively.

Glycosides↗
PubMed2004

Noncovalent interactions between aromatic compounds and dissolved humic acid examined by nuclear magnetic resonance spectroscopy.

We examined the molecular-level interactions of aromatic compounds with a humic acid that was extensively characterized with one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. Interactions of target compounds were evaluated by monitoring their NMR relaxation properties. Solid-state NMR revealed that the humic sample contains paraffinic carbon (31%), substituted aliphatic carbon (30%), and aromatic carbon (28%). The liquid-state experiments further identified amino acids, a range of carbohydrates, methoxylated aromatics (likely derived from lignin), and a series of aliphatic chains. The 13C spin-lattice relaxation time (T1) of site-specifically labeled naphthalene, 1-naphthol, and quinoline was found to decrease with increasing additions of humic acid. The 1H T1 values also were measured and demonstrated that the association with the humic acid was not specific because all the protons acquired the T1 value of the humic acid at the same rate. The lack of a chemical shift change and an increase in signal line broadening indicates that the interaction between these compounds and humic acid is noncovalent. These interactions were detected at low humic concentrations (5 mg C/L) and suggest that low concentrations of humic material, which are prevalent in both aquatic and terrestrial systems, will significantly affect the fate and transport of contaminants in the environment.

Carbon Isotopes↗
PubMed2001

Effects of eight polycyclic aromatic compounds on the survival and reproduction of the springtail Folsomia fimetaria L. (Collembola, isotomidae).

The effects of eight polycyclic aromatic compounds on the survival and reproduction of the collembolan Folsomia fimetaria L. were investigated in a well-characterized Danish agricultural soil. With the exception of acridine, polycyclic aromatic hydrocarbons (PAHs) and neutral N-, S-, and O-monosubstituted analogues showed similar toxicities to soil collembolans when the results were expressed in relation to total soil concentrations (mg/kg). The estimated concentrations resulting in a 10% reduction of reproductive output (EC10 values) were based on measured initial concentrations and were for acridine 290 mg/kg, carbazole 10 mg/kg, dibenzofuran 19 mg/kg, dibenzothiophene 7.8 mg/kg, fluoranthene 37 mg/kg, fluorene 7.7 mg/kg, phenantrene 23 mg/kg, and pyrene 10 mg/kg. When the EC10 values were converted to soil pore-water concentrations, they showed a highly significant correlation (r2 = 0.71, p < 0.01) to no-observed-effect concentrations for the freshwater crustacean Daphnia magna, as estimated by a quantitative structure activity relation (QSAR) for baseline toxicity (nonpolar narcosis). Only carbazole and acridine were more than two times more toxic (4.9 and 3.1, respectively) than expected from the Daphnia QSAR data. The latter result indicates that the toxicity of the tested substances is close to that expected for compounds with nonpolar narcosis as the mode of action. However, the relatively large uncertainties in the extrapolation method prevent final conclusions from being drawn.

Animals↗
PubMed2004

Bacterial transcriptional regulators for degradation pathways of aromatic compounds.

Human activities have resulted in the release and introduction into the environment of a plethora of aromatic chemicals. The interest in discovering how bacteria are dealing with hazardous environmental pollutants has driven a large research community and has resulted in important biochemical, genetic, and physiological knowledge about the degradation capacities of microorganisms and their application in bioremediation, green chemistry, or production of pharmacy synthons. In addition, regulation of catabolic pathway expression has attracted the interest of numerous different groups, and several catabolic pathway regulators have been exemplary for understanding transcription control mechanisms. More recently, information about regulatory systems has been used to construct whole-cell living bioreporters that are used to measure the quality of the aqueous, soil, and air environment. The topic of biodegradation is relatively coherent, and this review presents a coherent overview of the regulatory systems involved in the transcriptional control of catabolic pathways. This review summarizes the different regulatory systems involved in biodegradation pathways of aromatic compounds linking them to other known protein families. Specific attention has been paid to describing the genetic organization of the regulatory genes, promoters, and target operon(s) and to discussing present knowledge about signaling molecules, DNA binding properties, and operator characteristics, and evidence from regulatory mutants. For each regulator family, this information is combined with recently obtained protein structural information to arrive at a possible mechanism of transcription activation. This demonstrates the diversity of control mechanisms existing in catabolic pathways.

Bacteria↗
PubMed1999

Sample cleanup and reversed-phase high-performance liquid chromatographic analysis of polar aromatic compounds in groundwater samples from a former gas plant.

A method for the analysis of the polar aromatic compounds 1H-quinolin-4-one (Q), 10H-acridin-9-one (A), 5H-phenanthridin-6-one (P) and 9H-fluoren-9-one (F) in aqueous solutions has been developed. The method comprises steps for sample preparation (solid-phase extraction, cleanup) and analytical determination by means of reversed-phase high-performance liquid chromatography (RP-HPLC). For the cleanup step the suitability of two different sorbents (alternative A: silica gel, alternative B: LiChrolut EN) was investigated. Alternative B depicted several advantages, in particular higher sorbent capacity, faster and less complicated handling, higher recovery and better reproducibility. For Q, A and P, reproducibility of all method steps is better than 13%, with recovery rates ranging from 76% to 105% (n=3). Alternative B was applied to groundwater samples from a former gas plant. The analytes A and P could be detected at concentrations in the micro/l range.

Chemical Phenomena↗
PubMed2002

Soil microbial toxicity of eight polycyclic aromatic compounds: effects on nitrification, the genetic diversity of bacteria, and the total number of protozoans.

Eight polycyclic aromatic compounds (PACs) were tested for their toxic effect on the soil nitrification process, bacterial genetic diversity, and the total number of protozoans (naked amoebae and heterotrophic flagellates). After four weeks of exposure in a well-characterized agricultural soil, toxic effects were evaluated by comparison to uncontaminated control soils. All PACs affected the nitrification process, and the calculated no-observed-effect concentrations (NOECs) for nitrification were 79 mg/kg for pyrene, 24 mg/kg for fluoranthene, 26 mg/kg for phenanthrene, 72 mg/kg for fluorene, 23 mg/kg for carbazole, 22 mg/kg for dibenzothiophene, 75 mg/kg for dibenzofuran, and 1,100 mg/kg for acridine. For all substances but acridine, nitrification was the most sensitive of the three toxicity indicators evaluated. No effect of the tested substances on bacterial diversity was found, as measured by denaturant gradient gel electrophoresis. In general, only weak effects at very high concentrations were found for the protozoans. However, for acridine, protozoan numbers were reduced at lower concentrations than those that affected the nitrification process, that is, with a 5% reduction at 380 mg/kg. For effects on nitrification, toxicity (NOEC values) expressed as soil pore-water concentrations (log10(micromol/L)) showed a significant inverse relationship with lipophilicity (log octanol-water partition coefficient) of the substances (r2 = 0.69, p = 0.011, n = 8). This finding could indicate that the toxicity of substances similar to those tested might be predicted by a quantitative structure-activity relationship with lipophilicity as the predictor variable.

Animals↗
PubMed2006

Harnessing eugenol as a substrate for production of aromatic compounds with recombinant strains of Amycolatopsis sp. HR167.

To harness eugenol as cheap substrate for the biotechnological production of aromatic compounds, the vanillyl alcohol oxidase gene (vaoA) from Penicillium simplicissimum CBS 170.90 was cloned in an expression vector suitable for Gram-positive bacteria and expressed in the vanillin-tolerant Gram-positive strain Amycolatopsis sp. HR167. Recombinant strains harboring hybrid plasmid pRLE6SKvaom exhibited a specific vanillyl alcohol oxidase activity of 1.1U/g protein. Moreover, this strain had gained the ability to grow on eugenol as sole carbon source. The intermediates coniferyl alcohol, coniferyl aldehyde, ferulic acid, guajacol, and vanillic acid were detected as excreted compounds during growth on eugenol, whereas vanillin could only be detected in trace amounts. Resting cells of Amycolatopsis sp. HR167 (pRLE6SKvaom) produced coniferyl alcohol from eugenol with a maximum conversion rate of about 2.3 mmol/h/l of culture, and a maximum coniferyl alcohol concentration of 4.7 g/1 was obtained after 16 h biotransformation without further optimization. Beside coniferyl alcohol, traces of coniferyl aldehyde and ferulic acid were also detected.

Actinobacteria↗
PubMed2002

Ammonia free partial reduction of aromatic compounds using lithium di-tert-butylbiphenyl (LiDBB).

The reduction of a series of hetero- and carbocyclic aromatic compounds under ammonia free conditions is described. By using LiDBB as a source of electrons, bis(methoxyethyl)amine (BMEA) as a protonating agent, and THF as a solvent, we were able to accomplish reductions more usually performed under Birch type conditions. Moreover, the use of these conditions was further enhanced by the tolerance of the reducing system toward reactive electrophiles that cannot be used successfully in ammonia.

Journal Article↗