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At least 19 recordsLinked to original sources
PubMed1997

Developmental toxicity evaluation of phthalic acid, one of the metabolites of phthalic acid esters, in rats.

The objective of this study was to evaluate the developmental toxicity of phthalic acid (PA), which is one of the metabolites of phthalic acid esters (PAEs). Pregnant rats were given PA at a dose of 0 (control), 1.25, 2.5, or 5.0% in the diet on day 7 through day 16 of pregnancy. Average daily intakes of PA were 1021 mg/kg for the 1.25% group, 1763 mg/kg for the 2.5% group, and 2981 mg/kg for the 5.0% group. Maternal toxicity occurred in the 2.5 and 5.0% groups as can be seen by significant decreases in the maternal body weight gain and food consumption during the administration period. No significant changes in maternal parameters were found in the 1.25% group. Neither deaths nor clinical signs of toxicity were noted in any groups. No significant changes induced by PA were detected in the incidence of postimplantation loss and number and sex ratio of live fetuses. Significant decreases in the weight of male fetuses and number of ossification center of the caudal vertebrae were found in the 5.0% group. Morphological examinations of fetuses revealed no evidence of teratogenesis. Thus it appears unlikely that PA may be responsible for the production of the developmental toxicity of PAEs.

Animals↗
PubMed1980

Mass spectral fragmentation of phthalic acid esters.

Phthalic acid esters are among the most frequently encountered pollutants in biological extracts. They are very often detected in biological analysis using gas chromatography. Even using high resolution glass capillary columns, the identification of some of these esters remains difficult. In this paper the mass spectral fragmentation of a large number of phthalic acid esters is presented. Some criteria for the identification of the type of isomerism on the aromatic ring and the identification of the ester functions are also presented.

Esters↗
PubMed1983

Bacterial Decarboxylation of o-Phthalic Acids.

The decarboxylation of phthalic acids was studied with Bacillus sp. strain FO, a marine mixed culture ON-7, and Pseudomonas testosteroni. The mixed culture ON-7, when grown anaerobically on phthalate but incubated aerobically with chloramphenicol, quantitatively converted phthalic acid to benzoic acid. Substituted phthalic acids were also decarboxylated: 4,5-dihydroxyphthalic acid to protocatechuic acid; 4-hydroxyphthalic and 4-chlorophthalic acids to 3-hydroxybenzoic and 3-chlorobenzoic acids, respectively; and 3-fluorophthalic acid to 2-and 3-fluorobenzoic acids. Bacillus sp. strain FO gave similar results except that 4,5-dihydroxyphthalic acid was not metabolized, and both 3- and 4-hydroxybenzoic acids were produced from 4-hydroxyphthalic acid. P. testosteroni decarboxylated 4-hydroxyphthalate (to 3-hydroxybenzoate) and 4,5-dihydroxyphthalate but not phthalic acid and halogenated phthalates. Thus, P. testosteroni and the mixed culture ON-7 possessed 4,5-dihydroxyphthalic acid decarboxylase, previously described in P. testosteroni, that metabolized 4,5-dihydroxyphthalic acid and specifically decarboxylated 4-hydroxyphthalic acid to 3-hydroxybenzoic acid. The mixed culture ON-7 and Bacillus sp. strain FO also possessed a novel decarboxylase that metabolized phthalic acid and halogenated phthalates, but not 4,5-dihydroxyphthalate, and randomly decarboxylated 4-hydroxyphthalic acid. The decarboxylation of phthalic acid is suggested to involve an initial reduction to 1,2-dihydrophthalic acid followed by oxidative decarboxylation to benzoic acid.

Journal Article↗
PubMed2005

Investigations of cluster ions formed between cesium cations and benzoic, salicylic and phthalic acids by electrospray mass spectrometry and density-functional theory calculations. Toward a modeling of the interaction of Cs+ with humic substances.

A concerted theoretical (density-functional theory) and experimental electrospray mass spectrometry study was conducted on the formation of cesium cation adducts with small molecules taken as models of specific interactions sites in humic substances. Electrospray experiments with phenol, benzoic acid, salicylic acid, and phthalic acid, in methanolic solution containing cesium nitrate, were performed using a quadrupole ion trap. The formation of positively charged mixed clusters, [Cs(CsNO3)(n)(CsA1)(m)(Cs2A2)(p)]+ (A1 = benzoate, salicylate, and hydrogenophthalate, A2 = phthalate), was observed. Calculations of structures and bonding energetics of Cs+ in simple adducts formed with NO3-, CsNO3, A-, AH, and CsA are reported. The observation of variable cluster stoichiometry (n, m and p values) was interpreted in terms of more or less favorable interaction energies between Cs+ and the neutral species constituting the clusters. Phenol did not form clusters in significant abundances, despite a strong calculated interaction between Cs+ and cesium phenolate. This was attributed to its weak acid dissociation in the electrospray solution.

Acids, Carbocyclic↗
PubMed1998

Germ cell mutagenicity of phthalic acid in mice.

Mutagenicity of phthalic acid was evaluated by employing dominant lethal mutation and sperm head abnormality assays in male Swiss albino mice. For the dominant lethal mutation assay, adult male mice received a single intraperitoneal (i.p.) injection of either 40 mg or 80 mg/kg b.w. of phthalic acid for 5 consecutive days. For the sperm head abnormality assay, the mice were treated with 50, 100, 150, 200 and 300 mg/kg b.w. as a single i.p. injection. Treatment of adult male mice with phthalic acid resulted in induction of dominant lethal mutations and abnormal sperm heads. The results obtained indicate that phthalic acid is a germ cell mutagen.

Animals↗
PubMed1986

Phthalic acid excretion as an indicator of exposure to phthalic anhydride in the work atmosphere.

The concentration of phthalic acid was determined in the urine of nine subjects occupationally exposed to phthalic anhydride. For the determination, the urine samples were acidified, extracted with dimethyl ether, esterified with boron trifluoride/methanol and measured by electron capture gas chromatography. Environmental air samples were collected in Tenax tubes, eluted with methyl-t-butyl ether and assayed by electron capture gas chromatography. Significant correlations were found between the concentration in urine samples (range: 0.3-14.0 mumol/mmol creatinine), collected at different times of the day, and the time-weighed average atmospheric concentrations (range: 0.03-10.5 mg/m3). No conjugation of phthalic acid in the urine was observed. The detection limit for urine samples (10 ml) was 0.05 mumol/l) and that for air samples 0.4 microgram/m3. The method has potential for biological monitoring of workers exposed to phthalic anhydride. It was found that at atmospheric anhydride concentrations of about 30% of the hygienic reference value (6 mg/m3), which is applied in many market economies, a body-burden was caused which was not eliminated overnight.

Body Burden↗
PubMed1981

Degradation of phthalic acids by denitrifying, mixed cultures of bacteria.

Mixed cultures of bacteria, enriched from aquatic sediments, grew anaerobically on all three isomers of phthalic acid. Each culture grew anaerobically on only one isomer and also grew aerobically on the same isomer. Pure cultures were isolated from the phthalic acid (o-phthalic acid) and isophthalic acid (m-phthalic acid) enrichments that grew aerobically on phthalic and isophthalic acids. Cell suspension experiments indicated that protocatechuate is an intermediate of aerobic catabolism. Pure cultures which grew aerobically on terephthalic acid (p-phthalic acid) could not be isolated from the enrichments, and neither could pure cultures that grew anaerobically on any of the isomers. Cell suspension experiments suggested that separate pathways exist for the aerobic and anaerobic oxidation of phthalic acids. Each enrichment culture used only one phthalic acid isomer under anaerobic conditions, but all isomers were simultaneously adapted for the anaerobic catabolism of benzoate. Cells grown anaerobically on a phthalic acid immediately attacked the isomer under anaerobic conditions, whereas there was a lag before aerobic breakdown occurred, and, for phthalic and terephthalic acids, chloramphenicol stopped aerobic adaptation but had no effect on anaerobic catabolism. This work suggests that phthalic acids are biodegradable in anaerobic environments.

Journal Article↗
PubMed2003

CO(2)-H(2)-dependent anaerobic biotransformation of phthalic acid isomers in sediment slurries.

This paper investigates the anaerobic biotransformation of three isomers of phthalic acid and benzoic acid in sediment slurries under four different atmospheres [N(2), N(2)/H(2) (19:1, v/v), CO(2), and CO(2)/H(2) (4:1, v/v)]. Significant differences were observed in lag periods and biotransformation rates among the phthalic acid isomers and under the different atmospheres. In most cases, the relative biotransformation rates of the three isomers of phthalic acid were ortho-phthalic acid>isophthalic acid>terephthalic acid. Benzoate was transformed faster than any isomer of phthalic acid. Since biotransformation of phthalic acid isomers in sediment slurries was enhanced by high initial levels of H(2) and CO(2) in the headspace, we propose a pathway for phthalic acid biodegradation in which the initial transformation to benzoate is CO(2)-H(2) dependent. Acetogenic bacteria were investigated for their possible involvement in this transformation reaction, but when MPN counts were used to compare the growth dynamics of acetogenic bacteria with the time course of the terephthalic acid transformation under N(2)/H(2) (19:1, v/v) and CO(2)/H(2) (4:1, v/v) atmospheres, the results were inconclusive.

Anaerobiosis↗
PubMed2001

In situ X-ray observation of pedal-like conformational change and dimerization of trans-cinnamamide in cocrystals with phthalic acid.

In the crystals of phthalic acid trans-cinnamamide (1:2), two molecules of cinnamamide are connected with phthalic acid via a hydrogen bond to form a three-component assembly. The C=C double bonds of two cinnamamides take a criss-crossed arrangement with a center-to-center distance of 4.252(3) A and with a twist angle of 97.1(4) degrees. After a partial single-crystal-to-single-crystal transformation, X-ray analysis revealed the beta-type photodimer of cinnamamide in the assembly at 13.2(3)% conversion. This suggests that the pedal-like conformational change occurred for one of the cinnamamide molecules and the C=C bond of the other cinnamamide moved approximately parallel to form a cyclobutane ring.

Journal Article↗
PubMed2006

What are the sources of exposure to eight frequently used phthalic acid esters in Europeans?

Phthalic acid esters (phthalates) are used as plasticizers in numerous consumer products, commodities, and building materials. Consequently, phthalates are found in human residential and occupational environments in high concentrations, both in air and in dust. Phthalates are also ubiquitous food and environmental contaminants. An increasing number of studies sampling human urine reveal the ubiquitous phthalate exposure of consumers in industrialized countries. At the same time, recent toxicological studies have demonstrated the potential of the most important phthalates to disturb the human hormonal system and human sexual development and reproduction. Additionally, phthalates are suspected to trigger asthma and dermal diseases in children. To find the important sources of phthalates in Europeans, a scenario-based approach is applied here. Scenarios representing realistic exposure situations are generated to calculate the age-specific range in daily consumer exposure to eight phthalates. The scenarios demonstrate that exposure of infant and adult consumers is caused by different sources in many cases. Infant consumers experience significantly higher daily exposure to phthalates in relation to their body weight than older consumers. The use of consumer products and different indoor sources dominate the exposure to dimethyl, diethyl, benzylbutyl, diisononyl, and diisodecyl phthalates, whereas food has a major influence on the exposure to diisobutyl, dibutyl, and di-2-ethylhexyl phthalates. The scenario-based approach chosen in the present study provides a link between the knowledge on emission sources of phthalates and the concentrations of phthalate metabolites found in human urine.

Adolescent↗
PubMed2001

[Uncommon fluorescent properties of nano-structured terbium (III)-phthalic acid complex in polyvinylpyrrolidone].

Nano-sized terbium(III)-phthalic acid complex was prepared in polyvinylpyrrolidone. It's fluorescent spectrum has been investigated, compared to that of common terbium(III)-phthalic acid complex and terbium(III)-polyvinylpyrrolidone complex. The results show that fluorescent characterizations of Nano-sized terbium(III)-phthalic acid complex is obviously different from that of common terbium(III)-phthalic acid complex and terbium(III)-polyvinylpyrrolidone. The relative intensity and half-height width of main emission peaks are obviously varied, two splitting peaks are displayed.

Chelating Agents↗
PubMed1981

Potential for biodegradation of phthalic Acid esters in marine regions.

Di-(2-ethylhexyl) phthalate was the major phthalic acid ester in the Mississippi River estuary, with mean levels of 0.1 mug/g (dry weight) in surface sediments, 1.0 mug/liter in river water, and 0.7 mug/liter in delta water. Bacteria that grew aerobically on dibutyl phthalate and o-phthalic acid were readily detected in the sediments and water. Pure cultures of bacteria were isolated on seven different phthalic acid esters from freshwater and marine sources. The marine isolates were taxonomically diverse and grew on a variety of phthalic acid esters. Dibutyl phthalate and o-phthalic acid supported growth in full-strength synthetic sea-water medium, but Na -dependent catabolism was demonstrable only for o-phthalic acid.

Journal Article↗
PubMed1977

Asthma due to inhaled chemical agents--epoxy resin systems containing phthalic acid anhydride, trimellitic acid anhydride and triethylene tetramine.

Six workers with a diagnosis of occupational asthma and one with chronic bronchitis were examined for sensitivity to epoxy resin systems and certain of their components. In six cases the chemical agent responsible for their symptoms was identified by careful inhalation challenge testing, simulating their exposure at work and thus providing a precise aetiological diagnosis. In one worker asthma followed exposure to triethylene tetramine fume; four were sensitive to acid anhydrides, three to phthalic acid anhydride as a fume or powder and one to trimellitic anhydride. On worker thought to be sensitive to toluene di-isocyanate gave negative reactions to this and positive reactions to a phthalic acid anhydride epoxy resin and another thought to have asthma from acid anhydride fumes was found to be sensitive only to toluene di-isocyanate. Immediate, non-immediate or combined asthmatic reactions were elicited.

Adult↗