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PubMed2001

[Studies on chemical constituents of Schisandra propinqua (Wall.) Hook. f. et Thoms].

OBJECTIVE: To isolate and characterize compounds from the stems of Schisandra propinqua. METHOD: Extracting with solvent, isolating by column chromatography and identifying by the spectroscopic methods. RESULT: Six dibenzocyclooctadiene lignans were isolated and identified as tigloylgomisin P(1), angeloylgomisin O(2), angeloylisogomisin O(3), kadsulignan L(4), (+/-) 5,8-epoxyl-6, 7-dimethyl-2',3',2",3"-dimethylenedioxy-4', 1"-dimethyl-1,2:3,4-dibenzo-1, 3-cyclooctadiene(5) and wuweizisu C(6). CONCLUSION: Compounds 4 and 5 were the first two dibenzocyclooctadiene lignans with an 6,9-epoxy bridge cycle discovered in the genus Schisandra. The others were originally isolated from S. propinqua.

Cyclooctanes↗
PubMed1993

Characterization of particle- and vapor-phase organic fraction emissions from a heavy-duty diesel engine equipped with a particle trap and regeneration controls.

The effects of a ceramic particle trap on the chemical and biological character of the exhaust from a heavy-duty diesel engine have been studied during steady-state operation and during periods of trap regeneration. Phase I of this project involved developing and refining the methods using a Caterpillar 3208 engine, and Phase II involved more detailed experiments with a Cummins LTA10-300 engine, which met Federal 1988 particulate matter standards, and a ceramic particle trap with built-in regeneration controls. During the Phase I experiments, samples wee collected at the Environmental Protection Agency (EPA)* steady-state mode 4 (50% load at intermediate speed). Varying the dilution ratio to obtain a constant filter-face temperature resulted in less variability in total particulate matter (TPM), particle-associated soluble organic fraction (SOF), solids (SOL), and polynuclear aromatic hydrocarbon (PAH) levels than sampling with a constant dilution ratio and allowing filter-face temperature to vary. A modified microsuspension Ames assay detected mutagenicity in the SOF samples, and in the semivolatile organic fraction extracted from XAD-2 resin (XAD-2 resin organic component, XOC) with at least 10 times less sample mass than the standard plate incorporation assay. Measurement techniques for PAH and nitro-PAH in the SOF and XOC also were developed during this portion of the project. For the Phase II work, two EPA steady-state rated speed modes were selected: mode 11 (25% load) and mode 9 (75% load). With or without the trap, filter-face temperatures were kept at 45 degrees +/- 2 degrees C, nitrogen dioxide (NO2) levels less than 5 parts per million (ppm), and sampling times less than 60 minutes. Particle sizes were determined using an electrical aerosol analyzer. Similar sampling methods were used when the trap was regenerated, except that a separate dilution tunnel and sampling system was designed and built to collect all of the regeneration emissions. The SOF and XOC were extracted from their collection media with dichloromethane. Levels of 12 PAH and nitro-PAH compounds with known biological effects were determined using high-pressure liquid chromatography with fluorescence detection. Two additional dinitro-PAHs were analyzed semi-quantitatively, and several representative SOF and XOC samples were screened for three additional PAH compounds. Mutagenicity was assessed using the modified Ames microsuspension assay.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollutants↗
PubMed1988

On the de novo synthesis of polychlorinated dibenzo-p-dioxins and dibenzofurans.

Some possible intermediates or by-products in the synthesis of polychlorodibenzo-p-dioxins and dibenzofurans in municipal waste incinerators are presented. In stack gas samples from two different incinerators, the following compounds were tentatively identified: polychloromonobenzofurans, polychloromonobenzodioxins, monobromo-polychlorobenzenes and polychlorothiophenes. The occurrence of complete series of homologues and isomers with an increasing degree of chlorination suggests an analogous formation mechanism with common precursors. The presence of these compounds in the vapour phase, the non-regiospecific character of these reactions and the high reaction temperature and speed confirm a radical mechanism of formation.

Air Pollutants, Occupational↗
PubMed2002

Histochemical analysis of phenylphenalenone-related compounds in Xiphidium caeruleum (Haemodoraceae).

Phenylphenalenones represent a typical group of secondary metabolites of the Haemodoraceae. Some of these phenolic compounds show organ-specific distribution within the plant. However, detailed information on cellular localisation is still lacking. To this end, confocal laser-scanning microscopy, microspectral photometry and high-performance liquid chromatography were used to study the tissue localisation of phenylphenalenone-type compounds in Xiphidium caeruleum Aubl. From the autofluorescence potential of these compounds, specific distribution of allophanylglucosides and non-glucosidic compounds of the phenylphenalenone-type in distinct cells of the roots (apical meristem, cortex, cap, epidermis) and the shoot system was revealed. Fluorescence enhancement using "Naturstoff reagent A" (NA) indicated the occurrence of NA-positive natural products in the vacuoles of leaf epidermal cells. The present results provide new insights into the possible functions of phenylphenalenone-related compounds in the context of their localisation. Additionally, the advantages and limitations of the techniques are discussed.

Caffeic Acids↗
PubMed2006

Effects-directed analysis of organic toxicants in wastewater effluent from Zagreb, Croatia.

The organic toxicants present in the effluent of the main sewer of the city of Zagreb, Croatia were isolated and identified through the use of effects-directed characterisation techniques. At the time of investigation, the wastewater effluent received no treatment and was comprised of a mixture of effluent from domestic and industrial sources. The organic load of the wastewater was isolated by solid phase extraction and toxicity profiles obtained using reverse-phase HPLC. All procedures were evaluated through the analysis of a series of reference compounds of widely differing polarity. Toxicity profiles for EROD activity (CYP1A induction), vitellogenin induction (estrogenic activity), cytotoxicity (membrane stability and metabolic inhibition) were obtained using a rainbow trout (Oncorhynchus mykiss) primary hepatocyte bioassay. The suite of bioassays showed biological responses after exposure to the raw extracts for all the endpoints tested. However, a combination of mixture toxicity and cytotoxicity in the complex raw extract had some masking effect on the sub-lethal responses of vitellogenin and EROD induction. Bioassay testing of the fine fractions obtained by HPLC produced a range of endpoint-specific toxicity profiles for each sample. A number of compounds were identified by the use of GC-MS and LC-MS/MS as responsible for the observed effects. The steroid estrogens 17 beta-estradiol and estriol were identified by LC-MS/MS as estrogen receptor agonists in two of the estrogenic fractions. In addition, GC-MS analysis identified different alkylphenols, benzophenone and methylparaben which also contributed to the estrogenic activity of the sample. Polycyclic aromatic hydrocarbons (PAHs), alkyl substituted PAHs, nitro-polycyclic aromatic compounds (nitro-PACs), carbazoles and alkyl substituted carbazoles and other known CYP1A inducers were identified by GC-MS analysis as responsible for some of the observed EROD activity. Some active compounds remain unidentified.

Animals↗
PubMed1995

Aromatic-degrading Sphingomonas isolates from the deep subsurface.

An obligately aerobic chemoheterotrophic bacterium (strain F199) previously isolated from Southeast Coastal Plain subsurface sediments and shown to degrade toluene, naphthalene, and other aromatic compounds (J. K. Fredrickson, F. J. Brockman, D. J. Workman, S. W. Li, and T. O. Stevens, Appl. Environ. Microbiol. 57:796-803, 1991) was characterized by analysis of its 16S rRNA nucleotide base sequence and cellular lipid composition. Strain F199 contained 2-OH14:0 and 18:1 omega 7c as the predominant cellular fatty acids and sphingolipids that are characteristic of the genus Sphingomonas. Phylogenetic analysis of its 16S rRNA sequence indicated that F199 was most closely related to Sphingomonas capsulata among the bacteria currently in the Ribosomal Database. Five additional isolates from deep Southeast Coastal Plain sediments were determined by 16S rRNA sequence analysis to be closely related to F199. These strains also contained characteristic sphingolipids. Four of these five strains could also grow on a broad range of aromatic compounds and could mineralize [14C]toluene and [14C]naphthalene. S. capsulata (ATCC 14666), Sphingomonas paucimobilis (ATCC 29837), and one of the subsurface isolates were unable to grow on any of the aromatic compounds or mineralize toluene or naphthalene. These results indicate that bacteria within the genus Sphingomonas are present in Southeast Coastal Plain subsurface sediments and that the capacity for degrading a broad range of substituted aromatic compounds appears to be common among Sphingomonas species from this environment.

Bacteria, Aerobic↗
PubMed1987

Development of luminescence procedures to evaluate permeation of multi-ring polyaromatic compounds through protective materials.

This study describes two practical and simple luminescence techniques developed to evaluate the efficacy of protective clothing materials against permeation of multi-ring polyaromatic compounds contained in heavy oil and petroleum products. The procedures use a rapid and simple technique based on room temperature phosphorimetry and fluorescence detection in which a portable fiberoptics luminoscope was used.

Environmental Monitoring↗
PubMed1984

Inhibition and enhancement of phleomycin-induced DNA breakdown by aromatic tricyclic compounds.

Cationic aromatic tricyclic compounds including triphenylmethane dyes, phenazines, phenoxazines, acridines, phenothiazines, phenanthridinium compounds, anthracenes and xanthene dyes, which amplify cell killing in phleomycin-treated Escherichia coli B cells also modified phleomycin-induced breakdown of DNA to acid-soluble fragments. A plot of DNA breakdown as a function of concentration was bell-shaped for each of the active compounds, i.e. as the concentration increased, DNA breakdown was enhanced initially, but above a certain concentration, the proportion of DNA degraded declined, often to zero. One of the compounds, acriflavine, when tested also inhibited DNA breakdown following ultraviolet irradiation. A study, by sedimentation methods, of DNA single-strand breakage in phleomycin-treated E. coli cells, using 3 representative compounds, Crystal Violet, 3,6-diaminoacridine and Methylene Blue, revealed a consistent increase in DNA strand breaks as concentration of compound increased. In similar experiments with ethidium bromide the breakage yield/concentration curve exhibited a maximum. In general, however, it seems that the inhibition of DNA-breakdown observed at higher concentrations of these amplifying compounds is not explicable by an effect on the primary breakage event, but is due to suppression of exonucleolytic activity in the cells.

Acriflavine↗
PubMed1975

In vivo efficacy of 81.723 hfu, a new pleuromutilin derivative against experimentally induced airsacculitis in chicks and turkey poults.

The efficacy of the pleuromutilin derivative 81.723 hfu was tested in chicks and turkey poults by experimentally infecting them with Mycoplasma gallisepticum. The data were treated to obtain the mean effective doses, and these were compared to those obtained with tylosin tartrate. The compounds were administered either by ingluvial catheter or via the drinking water. Therapy was started on the day of inoculation or 7 days thereafter, respectively. The experiments showed that the compound 81.723 hfu was significantly more active in chickens than tylosin tartrate by both methods of administration of drinking water. In turkey poults the pleuromutilin derivative and tylosin tartrate had comparable activity.

Air Sacs↗
PubMed1994

Reduction and mutagenic activation of nitroaromatic compounds by a Mycobacterium sp.

Mycobacterium sp. strain Pyr-1 cells, which were grown to the stationary phase in media with and without pyrene, were centrifuged and resuspended in a medium containing 1-nitropyrene. Cells that had been grown with pyrene oxidized up to 20% of the added 1-nitropyrene to 1-nitropyrene-cis-9,10- and 4,5-dihydrodiols. However, cells that had been grown without pyrene reduced up to 70% of the 1-nitropyrene to 1-aminopyrene but did not produce dihydrodiols. The nitroreductase activity was oxygen insensitive, intracellular, and inducible by nitro compounds. Nitroreductase activity was inhibited by p-chlorobenzoic acid, o-iodosobenzoic acid, menadione, dicumarol, and antimycin A. Extracts from cells that had been grown without pyrene activated 1-nitropyrene, 1-amino-7-nitrofluorene, 2,7-dinitro-9-fluorenone, 1,3-dinitropyrene, 1,6-dinitropyrene, and 6-nitrochrysene to DNA-damaging products, as shown in Salmonella typhimurium tester strains by the reversion assay and by induction of the umuC gene. Activation of nitro compounds, as shown by the umu test, was enhanced by NADPH. This study shows that Mycobacterium sp. strain Pyr-1 metabolizes nitroaromatic compounds by both oxidative and reductive pathways. During reduction, it generates products that are mutagenic.

Bacterial Proteins↗
PubMed1995

The effect of fuel composition on the mutagenicity of diesel engine exhaust.

The effect of fuel composition on the mutagenicity of diesel engine emission was investigated. To this end, a fuel matrix comprising fuels with different contents of aromatic and naphthenic compounds was used. Extracts of the organic phase of raw exhausts obtained with different fuels were tested for mutagenicity in bacterial reversion assays. The results obtained demonstrate that the mutagenicity of diesel exhaust is largely dependent on the aromatic content of the fuel. In fact, mutagenicity was greatly reduced when the aromatic content of the fuel was lowered by hydrogen treatment. Conversely, mutagenicity was enhanced when the fuel was enriched with fractions of di- or triaromatic compounds. The addition of di- and trinaphthenic compounds only produced borderline mutagenicity. No clear relationship was observed between sulfur content of the fuel and mutagenicity of the exhaust. Assays in bacterial strains with different sensitivity to nitroaromatic compounds suggest a low contribution of the highly mutagenic dinitropyrenes to the responses observed, and a relatively greater contribution of 1-nitropyrene or other nitroaromatics processed by the same bacterial nitroreductase.

Mutagenicity Tests↗
PubMed2002

Novel phenalenone derivatives from a marine-derived fungus exhibit distinct inhibition spectra against eukaryotic DNA polymerases.

A number of compounds used for cancer chemotherapy exert their effects by inhibiting DNA replication. New inhibitors of DNA polymerases, therefore, could be potential candidates for new anti-cancer drugs. This study tested the effects of two phenalenone-skeleton-based compounds, which were isolated from a marine-derived fungus Penicillium sp., sculezonone-B (SCUL-B) and sculezonone-A (SCUL-A), upon DNA polymerase activity. Both compounds inhibited bovine DNA polymerases alpha and gamma, moderately affected the activity of DNA polymerase epsilon, and had almost no effect on HIV-reverse transcriptase and an E. coli DNA polymerase I Klenow fragment. Most notably, whereas SCUL-A inhibited pol beta (IC(50) = 17 microM), SCUL-B has only a weak influence upon this polymerase (IC(50) = 90 microM). Kinetic studies showed that inhibition of both DNA polymerases alpha and beta by either SCUL-A or SCUL-B was competitive with respect to dTTP substrate and noncompetitive with the template-primer. Whereas pol alpha inhibition by SCUL-B is competitive with respect to dATP, the inhibition by SCUL-A was found to be a mixed type with dATP substrate. The K(i) values of SCUL-B were calculated to be 1.8 and 6.8 microM for DNA polymerases alpha and gamma, respectively. The K(i) of DNA polymerase beta for SCUL-A was 12 microM and that for DNA polymerase alpha, 16 microM. Therefore, deletion of the OH-group at C12 enhanced inhibition of DNA polymerase beta. Since computational analyses of these two inhibitors revealed a remarkable difference in the distribution of negative electrostatic charge on the surface of molecules, we infer that different electrostatic charges might elicit different inhibition spectra from these two compounds.

Animals↗
PubMedDate not supplied

Salmonella mutagenicity of three complex mixtures assayed with the microsuspension technique. A WHO/IPCS/CSCM study.

In a collaborative study on complex mixtures, three complex mixtures and two pure compounds were assayed with the Salmonella microsuspension technique. The two pure compounds were benzo[a]pyrene (BaP) and 1-nitropyrene (1-NP). The three complex mixtures were standard reference materials (SRMs) from the U.S. National Institute of Standards and Technology, SRM 1649, SRM 1650 and SRM 1597. The two samples SRM 1649, an urban dust particulate matter, and SRM 1650, a diesel particulate matter, were sonicated with dichloromethane. Sample SRM 1597 was an extract of a coal tar sample with a complex mixture of polycyclic aromatic hydrocarbons. The microsuspension assay was performed with Salmonella strains TA98 and TA100 according to Kado et al. (1983) with minor modifications (Löfroth et al., 1988). The results showed that the microsuspension technique is a more sensitive assay than the plate incorporation method. Depending on sample, strain and metabolic condition the mutagenic responses were 3-37 times higher in the microsuspension assay than in the conventional plate incorporation assay. The microsuspension method is thus useful for environmental samples which are often available in only small amounts.

Air Pollutants↗
PubMed1992

Anti-oxidant activity of dibenzocyclooctene lignans isolated from Schisandraceae.

The anti-oxidant activity of nine dibenzocyclooctene lignans isolated from Schisandra chinensis, S. rubriflora, and Kadsura longipedunculata, respectively, was studied. Seven of the 9 lignans (1 mM) inhibited iron/cysteine-induced lipid peroxidation (malondialdehyde, MDA, formation) of rat liver microsomes as well as superoxide anion production in the xanthine/xanthine oxidase system. The actions of the 7 lignans were much more potent than vitamin E at the same concentration of 1 mM. Among the lignans, schisanhenol was the most active one. This compound also prevented the decrease of membrane fluidity of liver microsomes induced by iron/cysteine. The results indicated that seven of the lignans such as schisanhenol have anti-oxidant activities.

Animals↗
PubMed2002

The emission soot of biomass fuels combustion as a source of endocrine disrupters.

Emissions of biomass fuel combustion in residential stove from Chinese countryside were analyzed to determine the endocrine disrupters by using recombinant yeast bioassay. The results showed that there were significant steroid modulating activities found in combustion soot of five kinds of biomass fuels, which were wood, crop residue, grass, bush and rice straw. The steroid activities in the different sub-fractions from chromatographic separation were also determined, and the results indicated that polar fraction extracted by methanol and aromatic fraction extracted by benzene had relatively high steroid activities, and aliphatic fraction almost had no activity. The GC/MS results showed that polycyclic aromatic compounds and their derivatives, substituted phenolic compounds and their derivatives, aromatic carbonyl compounds, and higher molecular weight alcohols and ketones may be the main steroid disrupters in these soots.

Air Pollutants↗
PubMed1975

The mode of action of pleuromutilin derivatives. Location and properties of the pleuromutilin binding site on Escherichia coli ribosomes.

Using equilibrium dialysis techniques it could be demonstrated that (a) the pleuromutilin derivative 14-deoxy-14[(2-diethylaminoethyl)-mercaptoacetoxy] dihydromutilin HCl binds to one site per ribosome specifically, (b) the binding constant is 1.3 times 10(7) M(-1) and (c) chloramphenicol and puromycin compete with binding of the pleuromutilin derivative. Similarly the nucleotides CpA and CpCpA also displace the unsaturated derivative of the above-mentioned pleuromutilin compound. These findings suggest that the ribosomal binding site for pleuromutilin overlaps with that for chloramphenicol and analogs of the 3'-terminus of a tRNA, like puromycin or the nucleotides CpA and CpCpA.

Anti-Bacterial Agents↗