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Phthalic acid mimics 17beta-estradiol actions in WISH cells.

The object of this study was to evaluate whether phthalic acid, which is one of the metabolites of phthalic acid esters, exerts estrogenic actions in WISH cells, an immortalized cell line derived from human amniotic tissue. Our data demonstrate that phthalic acid (i) displaces [3H]estradiol from its binding sites, (ii) enhances the intracellular cyclic AMP concentration, without influencing adenylyl cyclase activity, (iii) stimulates or inhibits prostaglandin output, probably depending on the intracellular nucleotide level. The effects on prostanoid release are counteracted by addition of the protein-synthesis inhibitor cycloheximide, or when the diffusion of phthalic acid through the cell membrane is prevented. On the basis of our previous demonstration, that 17beta-estradiol exerts similar effects in WISH cells, we suggest that the molecular mechanisms underlying phthalic acid and steroid-hormone responses in this cell line are the same. This is the first demonstration that phthalic acid binds to the estrogen receptor with high affinity and mimics the hormone physiological actions.

3',5'-Cyclic-AMP Phosphodiesterases↗

[Phthalic acid esters and the human body].

Phthalic acid esters have been used for its softening and plastification effects as additives to various kinds of products: colours, paintings, glues, cosmetic products, inks, repellents, films, PVC-derived products including medical disposable PVC products. The authors present a basic review of literature on toxicologically important sources including medical disposable products. They refer about the deleterious effects on the mammalian organism, possibilities to replace phthalic acid esters by other softening and plasticizing remedies as well as the use of such kinds of materials, which do not require these additives.

Animals↗

Mono- and diesters from o-phthalic acid in leachates from different European landfills.

Leachates from 17 different landfills in Europe were analysed with respect to phthalates, i.e. phthalic acid diesters (PAEs) and their degradation products phthalic acid monoesters (PMEs) and ortho-phthalic acid (PA). Diesters are ubiquitous and the human possible exposure and potential to human health and environment has put them in focus. The aim of this study was to elucidate whether monoesters and phthalic acid could be traced in landfill leachates and in what concentrations they may be found. The results showed that phthalates were present in the majority of the leachates investigated. The monoesters appeared from 1 to 20 microg/L and phthalic acid 2-880 microg/L (one divergent value of 19 mg phthalic acid/L). Their parental diesters were observed from 1 to 460 microg/L. These observed occurrences of degradation products, of all diesters studied, support that they are degraded under the landfill conditions covered by this study. Thus, we have presented strong evidences to conclude that microorganisms in landfills degrade diesters released from formulations in a variety of products, including polyvinyl chloride (PVC) species.

Biodegradation, Environmental↗

Biodegradation of phthalic acid esters in river water and activated sludge.

The primary and ultimate biodegradability of phthalic acid, monobutyl phthalate, and five structurally diverse phthalic acid ester plasticizers in river water and activated sludge samples were determined via ultraviolet spectrophotometry, gas chromatography, and CO2 evolution. The compounds studied underwent rapid primary biodegradation in both unacclimated river water and acclimated activated sludge. When activated sludge acclimated to phthalic acid esters was used as the inoculum for the CO2 evolution procedure, greater than 85% of the total theoretical CO2 was evolved. These studies demonstrate that the phthalic acid ester plasticizers and intermediate degradation products readily undergo ultimate degradation in different mixed microbial systems at concentrations ranging from 1 to 83 mg/liter.

Bacteria↗

Percutaneous absorption of salicylic acid, theophylline, 2, 4-dimethylamine, diethyl hexyl phthalic acid, and p-aminobenzoic acid in the isolated perfused porcine skin flap compared to man in vivo.

Human risk assessment for topical exposure requires percutaneous absorption data to link environmental contamination to potential systemic dose. Human absorption data are not readily available, so absorption models are used. In vitro diffusion systems are easy to use but have proved to be somewhat unreliable and are not validated to man. This study compares percutaneous absorption in the isolated perfused porcine skin flap (IPPSF) system with that in man in vivo. The study design utilized the same compounds and the same dose concentration and vehicle in both systems. Methodology for each system was that which is routinely used ineach system. The skin surface was not protected during the absorption dosing period. Percutaneous absorption values were, for man and the IPPSF system, respectively: salicylic acid (6.5 +/- 5.0%; 7.5 +/- 2.6%), theophylline (16.9 +/- 11.3%; 11.8 +/- 3.8%), 2,4-dimethylamine (1.1 +/- 0.3%; 3.8 +/- 0.6%), diethyl hexyl phthalic acid (1.8 +/- 0.5%; 3.9 +/- 2.4%), and p-aminobenzoic acid (11.5 +/- 6.3%; 5.9 +/- 3.7%) (correlation coefficient was 0.78; p < 0.04). The skin surface wash recovery postapplication was similar for salicylic acid in man (53.4 +/- 6.3%) and the IPPSF system (48.2 +/- 4.9%). With the other compounds the majority of surface chemical was recovered in the surface wash and skin tape strip in the IPPSF system. With man, other than salicylic acid, only a few percent applied dose was recovered with surface washing and tape stripping. Since the wash procedure was effective with pig skin, we can assume that these chemicals in man were lost to adsorption to any clothing or bedding with the volunteers. The absorption in man was not less than that in the IPPSF. Assuming the dose was lost in man, it seems plausible that whatever compound was to penetrate human skin in solvent vehicle did so in the period of time before the chemical was removed. The IPPSF system appears to be a good model for predicting percutaneous absorption relative to man. This study design should be used to validate other systems to humans in vivo.

4-Aminobenzoic Acid↗

Anaerobic biodegradability of phthalic acid isomers and related compounds.

All three phthalic acid isomers (ortho, meta and para benzene dicarboxylic acid) are produced in massive amounts, and used in the chemical industry as plasticizers or for the production of polyester. Wastestreams generated during the production of phthalate isomers generally contain high concentrations of aromatic acids. To study the potential biodegradability of these primarily anthropogenic compounds in anaerobic bioreactors, biodegradability studies were performed. Compounds tested were benzoate, ortho-phthalate, isophthalate, terephthalate, dimethyl phthalate, dimethyl terephthalate, para-toluate and para-xylene. Seed materials tested were two types of granular sludge and digested sewage sludge. It was found that all phthalate isomers and their corresponding dimethyl-esters, could be completely mineralized by all seed materials studied. Lag phases required for 50% degradation of these compounds, ranged from 17 to 156 days. The observed degradation curves could be explained by growth of an initially small amount of organisms in the inoculum with the specific ability to degrade one phthalate isomer. The observed order in the length of the lag phases for the phthalate isomers is: phthalate < terephthalate < isophthalate. This order appears to be related to the environmental abundancy of the different phthalate isomers. The initial step in the degradation pathway of both dimethyl phthalate esters was hydrolysis of the ester sidechain, resulting in the formation of the corresponding mono-methyl-phthalate isomer and phthalate isomer. The rate limiting step in mineralization of both dimethyl phthalate and dimethyl terephthalate was found to be fermentation of the phthalate isomer. Para-toluate was degraded only by digested sewage sludge after a lag phase of 425 days. The observed degradation rates of this compound were very low. No mineralization of para-xylene was observed. In general, the differences in the lag phases between different seed materials were relatively small. These results indicate that the time needed for the start-up of anaerobic bioreactors treating wastewaters containing phthalic acid isomers, depends little on the microbial composition of the seed material applied, but may take several months.

Anaerobiosis↗

Characterization of polyesters prepared from three different phthalic acid isomers by CID-ESI-FT-ICR and PSD-MALDI-TOF mass spectrometry.

Polyesters prepared from the same diol, 2-butyl-2-ethyl-1,3-propanediol, but different phthalic acid isomers, phthalic, isophthalic, and terephthalic acid, were characterized by collision-induced dissociation electrospray ionization Fourier transform ion cyclotron resonance (CID-ESI-FT-ICR) and postsource-decay matrix-assisted laser desorption/ionization time-of-flight (PSD-MALDI-TOF) mass spectrometry. Sodiated dihydroxyl-terminated polyester oligomers containing five repeating units at m/z 1634 were selected as precursor ions for dissociation studies. Two main mechanisms occurred in the fragmentation of all of the polyesters, since dissociation of the oligomers was initiated by hydrogen rearrangement or transesterification reactions. Polyesters prepared from different phthalic acid isomers could be distinguished by their fragmentation behavior. Polyester prepared from phthalic acid was easily identified by using both CID-ESI-FT-ICR and PSD-MALDI-TOF mass spectrometry. However, distinguishing between the polyesters prepared from isophthalic and terephthalic acid succeeded marginally only with CID-ESI-FT-ICR mass spectrometry. Molecular dynamics calculations were used to obtain an idea of the fragmentation behavior of the polyesters. The low-energy structures of the precursor ions were determined, and the coordination of the oxygen atoms of the polyester oligomers to the sodium cation was examined more closely. Both the experimental and the theoretical studies showed that the sodium ion affinity of polyester changed with the phthalic acid isomer.

Journal Article↗

Correlation of observed and model vibrational frequencies for aqueous organic acids: UV resonance Raman spectra and molecular orbital calculations of benzoic, salicylic, and phthalic acids.

The aromatic carboxylic acids benzoic, salicylic and phthalic acid were used to study the interaction of soluble organics compounds with metal cations. To accomplish this, we have developed methods for studying the carboxylic acids using UV resonance Raman (UVRR) combined with molecular orbital density functional theory calculations. The pH values of the acid solutions were based on the pK(a)'s for the different acids to examine the neutral and charged species. Deprotonation of the organic acids was detectable down to 10(-4)M using UVRR (two orders of magnitude lower than previous vibrational spectroscopy studies). Limitations to decreasing the concentration lower using the current UVRR facilities are discussed. Two methods were used to calculate the optimized geometry and frequencies of the acids: explicit and continuum solvation. The frequencies from the experimental spectra were then compared to the theoretical results obtained from the two methods.

Benzoic Acid↗

Enantioresolution by the chiral phthalic acid method: absolute configurations of substituted benzylic alcohols.

Substituted benzylic alcohols were enantioresolved by the chiral phthalic acid method as follows; 1) esterification of racemic alcohols with chiral phthalic acid, 2) separation of a diastereomeric mixture of the esters formed by HPLC on silica gel, and 3) recovery of enantiopure alcohols from the separated esters. The absolute configurations of chiral phthalic acid esters of benzylic alcohols were unambiguously determined by the X-ray crystallography using the campharsultam moiety as the internal standard of absolute configuration.

Benzyl Alcohols↗

Biological effects of di-(2-ethylhexyl) phthalate and other phthalic acid esters.

Esters of o-phthalic acid are widely distributed in the ecosystem. The phthalate acid esters (PAE's) are used as plasticizers in the manufacture of polyvinylchlorides. They are also used as solvents in certain industrial processes and as vehicles for pesticides. The PAE's are used in enormous quantities for a variety of industrial uses in the formulation of plastics. While there are a number of important PAE's, di-ethylhexyl phthalate has perhaps been used the most extensively in the formulation of plastics used in medical devices and blood bag assemblies. The metabolism, biodistribution and excretion varies to some extent among the various PAE's. There are species differences with respect to the metabolism of the PAE's. The route of administration, and the level and length of exposure, are known to affect the toxicological profile of the various PAE's. There is little evidence of bioaccumulation of the various PAE's, and only at very large doses have there been reports of overt toxicity. Evidence for the carcinogenicity of certain PAE's apparently is related to prolonged exposure to high levels.

Animals↗

Estimation of the environmental contamination by phthalic acid esters leaching from household wastes.

Phthalic acid esters (PAE) have been used as plasticizers in many products. Here we estimate the contaminating potential of PAE codisposed with domestic wastes. In order to determine the maximum threat to the environment, we analysed several fractions of different household wastes. A maximum of 2.6% of di-(2-ethylhexyl) phthalate (DEHP) was measured in 'compound materials'. More than 90% of all the PAE present in the refuse was due to DEHP. Assuming defined compositions of the refuse we calculated that approx. 1 kg of phthalate esters per ton of dry waste may be codisposed. The actual amount of PAE that could be eluted by the leachate was estimated using laboratory bioreactors which were filled with waste of exactly known composition. Only approx. 1 g of PAE per ton of dry waste was leached. However, the elution of hydrophobic DEHP by the leachate is dependent on the composition of the waste which gave rise to different concentrations of dissolved organic carbon. Because of the experimental setup the amounts of leached PAE represent minimum levels of possible environmental contamination. Hence, there will be a constant output of PAE from unlined municipal landfills for decades.

Environmental Monitoring↗

[Determination of phthalic acid esters in textiles by solid phase extraction-gas chromatography].

A method was established for the simultaneous determination of some phthalic acid esters, namely, dimethyl phthalate (DMP), diethyl phthalate (DEP), dipropyl phthalate (DPrP), dibutyl phthalate (DBP), diamyl phthalate (DAP), dihexyl phthalate (DHP), benzyln-butyl phthalate (BBP), di-(2-ethylhexyl) phthalate (DEHP), dicyclohexyl phthalate (DCHP), di-n-octyl phthalate (DNOP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP) in textiles by solid phase extraction (SPE) coupled with gas chromatography (GC). The phthalic acid esters in textiles were extracted by Soxhlet extraction with hexane, the extracts were then cleaned up and enriched by a strong anion exchange (SAX) SPE cartridge. The parameters affecting the purification efficiency of SPE cartridge, such as solvent conditioning, rinsing, and elution, were studied. Conditioning with 5 mL hexane and rinsing with 3 mL isooctane were proved to be the optimal conditions. Of the several solvent ratios (ethylacetate in hexane) used for selective elution of phthalic acid esters from the SAX SPE cartridge, the 15% (v/v) content for ethylacetate in hexane gave the best result. Under the optimized conditions, the recoveries of phthalic acid esters for spiked standards (n=7) were 86.3%-102.7%, and the relative standard deviations (RSDs) were less than 5%. In this method the detection limits for DMP, DEP, DPrP, DBP, DAP, BBP, DCHP, DEHP, DNOP were all below 1 mg/kg, and the detection limits for DINP and DIDP were 1.74 mg/kg and 1.55 mg/kg respectively. This SPE-GC method is sensitive, accurate and suitable for the analysis of phthalate environmental hormones in textiles.

English Abstract↗

Phthalic acid dermatitis caused by an organostannic compound, tributyl tin phthalate.

We report a case of primary irritant contact dermatitis caused by an organostannic insecticide, tributyl tin phthalate, which has been thought to be stable and safe. A factory worker has been in contact with raw tributyl tin phthalate on one leg. Soon after taking a hot-water bath, he developed severely painful erythema on this leg. Patch tests and chemical analysis revealed that hot water hydrolyzed tributyl tin phthalate and produced concentrated phthalic acid. Since phthalic acid, a weak acid, was then concentrated, an acute irritant reaction appeared in this patient.

Accidents, Occupational↗

Infrared spectra of phthalic acid, the hydrogen phthalate ion, and the phthalate ion in aqueous solution.

The infrared spectra of a series of aqueous solutions containing phthalic acid (1,2-benzenedicarboxylic acid) and varying pH were examined using attenuated total reflection Fourier transform infrared spectroscopy and potentiometry. The basis spectra of phthalic acid, the hydrogen phthalate ion, and the phthalate ion were isolated using a factor analysis in which the absorbance of these species varies with pH and total phthalate concentration according to equilibrium and mass balance relations. Assignments of these basis spectra were made by comparison with spectra calculated ab initio. The conditional formation constants of phthalic acid and the hydrogen phthalate ion were determined at 25.0+/-0.1 degrees C in 0.6 M NaCl ionic media using infrared spectroscopy and in 1.5 M NaCl ionic media using both infrared spectroscopy and potentiometry.

Carboxylic Acids↗

Monitoring of phthalic acid monoesters in river water by solid-phase extraction and GC-MS determination.

An analytical method for monitoring 10 phthalic acid monoesters in river water was investigated by solid-phase extraction, methylation with diazomethane, and GC-MS. Two cartridge-type solid phases packed with octadesyl-coated silica (C18) and styrenedivinyl polymer (PS-2) and one disk-type solid phase made from octadesyl-coated styrenedivinylbenzene polymer (SDB-XD) were investigated in solid-phase extraction. PS-2 gave the highest recoveries of the three solid phases, and recoveries of more than 80% of the monoesters in filtered water samples were obtained at pH 2 to 3 with PS-2 at the spiked level of 0.1 microg L(-1), except for monomethyl-phthalate (MMP), in which more than 72% of the monoesters were recovered. For the monoesters in the suspended solids (SS), an acidic methanol extract of SS was added to purified water acidified to pH 2, and the monoesters were extracted with PS-2. The recoveries of the monoesters in SS were more than 80%, but the recoveries of MMP were more than 57%. The method detection limit (MDL) of each phthalic acid monoester in 500 mL of water sample and in 2 mg of dry weight of SS ranged from 0.010 to 0.030 microg L(-1) and from 1 to 11 microg g(-1), respectively. Monitoring of phthalic acid monoesters in the Tama River in Tokyo was conducted every month from March 1999 to February 2000 using the present method. MMP, mono-n-butyl-phthalate (MBP), and mono-(2-ethylhexyl)-phthalate (MEHP) were detected at concentrations of 0.030-0.0340, 0.010-0.480, and 0.010-1.30 microg L(-1), respectively, in the filtered water samples but were not detected in SS. Dimethyl-phthalate (DMP), di-n-butyl-phthalate (DBP), and di-(2-ethylhexyl)-phthalate (DEHP) were detected in the river water at concentrations of 0.010-0.092, 0.008-0.540, and 0.013-3.60 microg L(-1), respectively. Diethyl-, di-iso-butyl-, and benzylbutyl-phthalates were also detected at concentrations of nanograms per liter, whereas the corresponding monoesters did not appear. The concentrations of MBP and MEHP in the river water were slightly lower than those of the corresponding diesters at the majority of sampling sites and sampling times.

Chemistry Techniques, Analytical↗

Determination of phthalic acid, mono-(2-ethylhexyl) phthalate and di-(2-ethylhexyl) phthalate in human plasma and in blood products.

Pretreatment for the determination of phthalic acid, mono-(2-ethylhexyl) phthalate (MEHP) and di-(2-ethylhexyl) phthalate (DEHP) in human serum or plasma, and the determination of these compounds in blood products by high-performance liquid chromatography was studied. The amount of phthalic acid, MEHP and DEHP, migrated into blood products from a flexible bag, was studied. About 0.1% of DEHP in a flexible bag was found to have migrated into human platelet plasma. Most of the MEHP and phthalic acid detected in human platelet plasma was not derived from the flexible bag but was produced by enzymatic hydrolysis of the migrated DEHP. The amount of DEHP eluted into blood products from the flexible bag differed, depending upon storage time, storage temperature, etc.

Acetonitriles↗