Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dinitrocresols”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Degradation of 2,4-dinitrophenol and selected nitroaromatic compounds by Sphingomonas sp. UG30.

Sphingomonas strain UG30 mineralizes both p-nitrophenol (PNP) and pentachlorophenol (PCP). Our current studies showed that UG30 oxidatively metabolized certain other p-substituted nitrophenols, i.e., p-nitrocatechol, 2,4-dinitrophenol (2,4-DNP), and 4,6-dinitrocresol with liberation of nitrite. 2,6-DNP, o- or m-nitrophenol, picric acid, or the herbicide dinoseb were not metabolized. Studies using 14C-labelled 2,4-DNP indicated that in glucose-glutamate broth cultures of UG30, greater than 90% of 103 microM 2,4-DNP was transformed to other compounds, while 8-19% of the 2,4-DNP was mineralized within 5 days. A significant portion (20-50%) of the 2,4-DNP was metabolized to highly polar metabolite(s) with one major unidentified metabolite accumulating from 5 to 25% of the initial radioactivity. The amounts of 2,4-DNP mineralized and converted to polar metabolites was affected by glutamate concentration in the medium. Nitrophenolic compounds metabolized by UG30 were also suitable substrates for the UG30 PCP-4-monooxygenase (pcpB gene expressed in Escherichia coli) which is likely central to degradation of these compounds. The wide substrate range of UG30 could render this strain useful in bioremediation of some chemically contaminated soils.

2,4-Dinitrophenol↗

Urine profile analysis by field desorption mass spectrometry, a technique for detecting metabolites of xenobiotics. Application to 3,5-dinitro-2-hydroxytoluene.

A technique for the detection of biotransformation products of xenobiotics in crude urine extracts by field desorption mass spectrometric profile analysis is described. The method comprises determination of peak profiles of a series of blank and test samples using low resolution field desorption mass spectrometry, comparison of averaged peak profiles and noise reduction by means of Fisher and ratio weighting of peak intensities. Application of the technique to 3,5-dinitro-2-hydroxytoluene has resulted in the detection of two hitherto unknown metabolites in rat urine. By thin-layer co-chromatography, high resolution electron impact mass spectrometry and thin-layer chromatographic/field desorption mass spectrometric analysis they could be identified as 3,5-dinitro-2-hydroxybenzenemethanol and 3,5-diacetamido-2-hydroxytoluene.

Animals↗

The effects of five weeks treatment with dinitro-o-cresol- or trifluralin-containing pesticides on the germ cells of male mice.

The effects of two pesticides, the insecticide-herbicide Krezonit E, which contains 50% dinitro-o-cresol, and the herbicide Olitref, which contains 26% trifluralin (2,6-dinitro-N,N-dipropyl-4-trifluoromethylaniline), on the gonads and germ cells of male mice were studied. The pesticides were given twice a week for 5 weeks in i.p. doses of 0.6 mg kg-1 for Krezonit E and 6.0 mg kg-1 for Olitref. These doses are 1% of the i.p. LD50. Cytogenic analysis of germ cells carried out from 3 weeks onwards after the last treatment day showed that Olitref significantly increased the frequency of germinal chromosomal abnormalities at 6-7 weeks after treatment. This pesticide increased the frequency of autosomal univalents X/Y separations at meiotic metaphase and multivalent configurations. Krezonit E did not increase significantly the number of chromosomal abnormalities, although there was some increase at 3 weeks, mainly in the form of autosomal univalents.

Animals↗

Toxic effects, at three pH levels, of two reference molecules on common carp embryo.

Early life-stage survival, motility, and growth toxicity tests were carried out on common carp (Cyprinus carpio L.) endotrophic embryo, with two reference molecules (captafol and DNOC), from fertilization to the end of the first two-thirds period of mortalities by starvation. Thirteen days duration exposure was performed in daily renewed medium, at 24.5 degrees C, in standard synthetic water, at three pHs (6.9, 7.8, 9.0), in the presence of 10 mM/liter nontoxic pH buffer. Nominal concentrations of toxicants were 0.0, 0.25, 0.5, 1.0, and 2.0 mg/liter. Toxic effects on survival, motility, and growth decreased with increasing pH. From pH 6.9 to 9.0, the "no-observed-effect concentrations" differed by a factor greater than 8. Motility and growth cannot be considered, at population level, as true sublethal embryo-larval toxicity criteria. The toxicological interpretation of these results is discussed. They confirm the need of multifactorial methods for toxic risks and effects assessment on fish early life stages in the environment.

Animals↗

Mutagenicity of DNOC in Drosophila melanogaster.

The insecticide/ascaricide dinitro-ortho-cresol (DNOC) was tested for mutagenicity in BASC or Muller-5 test with Drosophila melanogaster. The frequencies of induced sexlinked recessive lethals in premeiotic and postmeiotic germ cell stages of spermatogenesis were determined after exposure of adult wild-type males by oral application of DNOC. Sex-linked recessive lethals were scored in the F2 generation according to standard procedures. The mutagenic activity of DNOC at concentrations of 0.25 to 1.01 mM (50-200 ppm) in postmeiotic germ cell stages (11 lethals/1570 chromosomes tested = 0.70%) > premeiotic stages (3/1001 = 0.29%). The mutations rate in all germ cell stages was 0.59% (18/3140). The lowest effective concentration for the induction of recessive lethals in nature sperm was 0.25 mM which is 1/3 to 1/2 LD50 which is approximately 0.61 mM. The frequency of spontaneously occurring lethality was 0.06 (1/1718). The data presented here show significant differences in Kastenbaum-Bowman test. Dimethylnitrosamine (6.8 mM = 500 ppm) induced a rate of 21.0% of lethals (112/534).

Animals↗

Biodegradation of the pesticide 4,6-dinitro-ortho-cresol by microorganisms in batch cultures and in fixed-bed column reactors.

A mixed culture of microorganisms able to utilize 4,6-dinitro-ortho-cresol (DNOC) as the sole source of carbon, nitrogen and energy was isolated from soil contaminated with pesticides and from activated sludge. DNOC was decomposed aerobically in batch cultures as well as in fixed-bed column reactors. Between 65% and 84% of the substrate nitrogen was released as nitrate into the medium, and 61% of the carbon from uniformly 14C-labelled DNOC was recovered as 14CO2. The mixed microbial culture also decomposed 4-nitrophenol and 2,4-dinitrophenol but not 2,3-dinitrophenol, 2,6-dinitrophenol, 2,4-dinitrotoluene, 2,4-dinitrobenzoic acid or 2-sec-butyl-4,6-dinitrophenol (Dinoseb). Maximal degradation rates for DNOC by the bacterial biofilm immobilized on glass beads in fixed-bed column reactors were 30 mmol day-1 (1 reactor volume)-1, leaving an effluent concentration of less than 5 micrograms l-1 DNOC in the outflowing medium. The apparent Ks value of the immobilized mixed culture for DNOC was 17 microM. Degradation was inhibited at DNOC concentrations above 30 microM and it ceased at 340 microM, possibly because of the uncoupling action of the nitroaromatic compound on the cellular energy-transducing mechanism.

2,4-Dinitrophenol↗