PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Phthalate esters”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources
PubMed1976

Effects of phthalate esters on the respiration of rat liver mitochondria.

The effects of phthalate esters on the oxidation of succinate, glutamate, beta-hydroxybutyrate and NADH by rat liver mitochondria were examined and it was found that di-n-butyl phthalate (DBP) strongly inhibited the succinate oxidation by intact and sonicated rat mitochondria, but did not inhibit the State 4 respiration with NAD-linked substrates such as glutamate and beta-hydroxybutyrate. However, oxygen uptake accelerated by the presence of ADP and substrate (State 3) was inhibited and the rate of oxygen uptake decreased to that without ADP (State 4). It was concluded that phthalate esters were electron and energy transport inhibitors but not uncouplers. Phthalate esters also inhibited NADH oxidation by sonicated mitochondria. The degree of inhibition depended on the carbon number of alkyl groups of phthalate esters, and DBP was the most potent inhibitor of respiration. The activity of purified beef liver glutamate dehydrogenase [EC 1.4.1.3] was slightly inhibited by phthalate esters.

Adenosine Diphosphate↗
PubMed1978

Phthalate ester plasticizers: a new class of marine pollutant.

Phthalate ester plasticizers have been detected in the open-ocean environment. Samples consisting of water, sediment, air, and biota from the Gulf of Mexico and of water and air from the North Atlantic were analyzed and found to contain two phthalate esters, di-(2-ethylhexyl) phthalate (DEHP) and di-n-dibutyl phthalate (DBP): the concentrations of polychlorinated biphenyls (PCB's) and DDT's (p,p'-DDT and p,p'-DDE) were also determined. Like the ubiquitous PCB's and DDT's, the phthalate plasticizers were found in almost all samples analyzed; DEHP was present at higher concentrations than the PCB's or DDT's in water and sediment. The environmental impact of the concentrations found in these studies, coupled with the continued high production and wise use of these plasticizers, requires assessment.

Air Pollutants↗
PubMed1977

Effects of phthalate esters on the latent ATPase and swelling of mitochondria.

Phthalate esters have shown to stimulate the latent ATPase [EC 3.6.1.3] activity and induce mitochondrial swelling. Among the tested phthalate esters, di-n-butyl phthalate (DBP) exhibited the greatest activity, and the activity decreased progressively as the alkyl chain was lengthened or shortened. The DBP-stimulated ATPase was oligomycin-sensitive. The degree of stimulation of the ATPase was proportional to the extent of mitochondrial swelling induced by DBP in 0.1 M Tris-HCl (pH 7.2) containing 0.25 M sucrose. However, the swelling was dependent on the tonicity of the solution or the concentration of chloride ions, while the stimulation of ATPase was independent of these factors. Swelling was strongly induced by DBP at slightly acidic rather than neutral or alkaline pH. The pH-activity curve of DBP-stimulated ATPase was in inverse correlation with that of swelling, which showed a rather flat maximum at pH 8.0. When bovine serum albumin (BSA) was added to a solution containing mitochondria before addition of DBP, swelling was no longer caused by DBP, though the latent ATPase was stimulated to the same extent in the absence of added BSA.

Adenosine Triphosphatases↗
PubMed1977

Micro-determination of total phthalate esters in biological samples by gas-liquid chromatography.

A method was investigated in which all of the phthalate esters in biological samples were determined as phthalic acid by gas-liquid chromatography. The method is based on the separation of phthalate esters from the sample with n-hexane, saponification of the esters with an alkaline ethanolic solution to give phthalic acid, purification of the acid by extraction with diethyl ether and column chromatography using silica gel, and conversion of the acid into bis(2,2,2-trifluoroethyl) phthalate with a 2,2,2-trifluoroethanol solution containing boron trifluoride. The derivative obtained is highly sensitive to an electron-capture detector, giving a sensitivity of 0.1 pg. Biological samples fortified with di(2-ethylhexyl) phthalate at levels of 5-100 ppb were analyzed, with recoveries of 70-100%.

Alkalies↗
PubMed1979

Determination of chlorinated pesticide residues in foods. II. Simultaneous analysis of chlorinated pesticide and phthalate ester residues by using AgNO3-coated Florisil column chromatography for cleanup of various samples.

A simplified method suitable for simultaneous analysis of chlorinated pesticide and phthalate ester residues in various foods was developed. Chemical residues were quantitatively extracted from fatty and vegetable samples with acetonitrile as follows: Chemical standard in 0.5 mL ethanol solution was added to 10 g homogenized sample. After 3 hr, pork and beef were extracted 3 times with 20 mL portions of acetonitrile. The acetonitrile layers were diluted with water and extracted with n-hexane. Rice samples were combined with 10 mL water, 5 mL acetonitrile and 1 mL ethanol and extracted 3 times with 20 mL portions of n-hexane. The n-hexane concentrate from each sample was submitted to AgNO3-coated Florisil column chromatography. The AgNO3 coating adequately adsorbed interfering coextractives. Extracts of fish and vegetable samples were separated into 2 fractions by the above column chromatography. Supplemental cleanup procedures were also developed to accurately determine phthalate esters eluted in the second fraction. Satisfactory gas chromatograms were obtained for most samples.

Animals↗
PubMed1979

The influence of phthalate esters on human plasma lecithin/cholesterol acyltransferase.

The effect of various phthalate esters on the lecithin/cholesterol acyltransferase activity in man was studied in vitro. The enzymatic activity was strongly reduced with all phthalates except for the dimethyl phthalate. The inhibition rate depends on the phthalate concentration and also on the carbon number of the alkyl groups of phthalates.

Acyltransferases↗
PubMed2026

Unveiling phthalate esters biodegradation from microbial community to Pseudarthrobacter scleromae HL-1: Kinetics, genomic insights, pathways, toxicity assessment and environmental remediation.

Phthalate esters (PAEs) are ubiquitous synthetic plasticizer pollutants posing severe ecological and human health risks. This study compared microbial community structures and dibutyl phthalate (DBP) degradation kinetics of two consortia: 7-day enriched MC1 (50 mg/L DBP) and 6-cycle acclimated MC7 (50-1000 mg/L DBP), demonstrating directional DBP stress selection generated a low-diversity, highly specialized degradative community with a 25.4 mg/L/h maximum degradation rate (Vmax), 1.68-fold higher than MC1. Four dominant DBP-degrading strains were isolated from MC7; Pseudarthrobacter scleromae HL-1 showed the highest efficiency with 17.1 mg/L/h Vmax and complete 500 mg/L DBP removal within 72 h, broad substrate spectrum, and strong adaptability after optimization. Whole-genome sequencing and GC-MS/MS elucidated a dual-parallel DBP mineralization pathway, first reported in Pseudarthrobacter, integrating ester hydrolysis and side-chain β-oxidation. ECOSAR and Chlorella vulgaris bioassays confirmed progressive toxicity attenuation, with > 99% relative toxicity reduction after 72 h and no toxic intermediate accumulation. Natural lake water trials with trace background PAEs showed HL-1 successfully colonized aquatic environments, reshaped indigenous communities into synergistic degradative consortia, and achieved 99.2% DBP removal in 84 h. This work provides comprehensive insights into PAE biodegradation mechanisms from community to single strain and highlights HL-1 as a promising candidate for remediating PAE-polluted aquatic ecosystems.

Genomic analysis↗
PubMed1976

Identification and determination of phthalate esters in river water by high-performance liquid chromatography.

The use of three separation modes (normal and reversed-phase adsorption chromatography and gel chromatography) with an ultraviolet absorption detector of variable wavelength provides the basis for a very sensitive method for the determination of phthalate esters in river water. Phthalates in river water were extracted with n-hexane and the extract was injected into three chromatographic systems [porous polymer beads-n-hexane (at 224 nm); porous polymer beads-methanol (at 224 nm); and polystyrene GPC gel-chloroform (at 243 nm)] without any pre-treatment such as clean-up concentration. Average concentrations of approximately 45 ppb of di-n-butyl phthalate (DBP) and 10 ppb of di-2-ethylhexyl phthalate (DOP) were found in a given river water. Phthalate concentrations as low as 2 ppb could be determined. The limit of determination could be lowered by the use of concentration process. The absolute detection limit was 2 ng of DOP at 224 nm.

Adsorption↗
PubMed1978

Gel filtration of phthalate esters.

Calibration of the gel-filtration system polystyrene beads-benzene is effected in terms of the molecular weights of solutes without using a void volume indicator. Correction for dead volumes is made by incorporating in the loads a dye producing a peak of accurately known elution volume to serve as reference point on a stripchart absorption diagram of column effluent. The calibrated column separates small amounts of plasticizer phthalate esters from excess of lipids extracted from biological materials, providing evidence of identity in samples sufficiently pure for estimation by gas chromatography. Further purification can, where necessary, be achieved quantitatively by high-performance liquid chromatography on silicic acid with 2% (v/v) diisopropyl ether in n-hexane as mobile phase.

Chromatography, Gel↗
PubMed1979

Structural requirements for the inhibition of phthalate ester hydrolysis in rainbow trout by methylenedioxyphenyl compounds.

1. The ability of a number of methylenedioxyphenyl compounds and paraoxon to inhibit the hydrolysis and oxidation of di-2-ethylhexyl phthalate by rainbow trout tissue preparations was examined. 2. In addition to paraoxon, only the methylenedioxyphenyl compounds with long side-chains (piperonyl butoxide and tropital) inhibited the hydrolysis of di-2-ethylhexyl phthalate by trout liver subcellular fractions and trout serum. 3. Paraoxon decreased the production of the major metabolite of di-2-ethylhexyl phthalate by trout liver microsomes (+ NADPH) suggesting that this metabolite arises via further metabolism of mono-2-ethylhexyl phthalate.

Animals↗