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The Science of the Total Environment Nov 2022Food ingestion has been established as an important human exposure route to many environmental contaminants (brominated flame retardants, dioxins, organochlorine...
Food ingestion has been established as an important human exposure route to many environmental contaminants (brominated flame retardants, dioxins, organochlorine pesticides etc). However, information regarding dietary exposure to organophosphate esters (OPEs) in the UK remains limited. This study provides the first comprehensive dataset on OPEs in the UK diet by measuring concentrations of eight OPEs in 393 food samples, divided into 15 food groups, collected from Birmingham, UK. All target OPEs were measured above the limit of quantification in at least one of the food groups analysed. Concentrations were highest (mean ∑OPEs = 18.4 ng/g wet weight (ww)) in milk and milk products, followed by those in cereal and cereal products (mean ∑OPEs = 15.9 ng/g ww), with concentrations lowest in chickens' eggs (mean ∑OPEs = 1.61 ng/g ww). Interestingly, concentrations in animal-derived foods (mean ∑OPEs = 44.2 ng/g ww) were statistically indistinguishable (p˃0.05) from plant-derived foods (mean ∑OPEs = 36.8 ng/g ww). Estimated daily dietary intakes (EDIs) of ∑OPEs under mean and high-end exposure scenarios for the four age groups considered were: toddlers (420 and 1547 ng/kg bw/day) ˃ children (155 and 836) ˃ elderly (74.3 and 377) ˃ adults (62.3 and 278) ng/kg bw/day, respectively. Baby food contributed 39 % of ∑OPEs exposure for toddlers, with non-alcoholic beverages contributing 27 % of exposure for children, while cereal and cereal products (25 %) and fruits (22 %) were the main contributors for adults and the elderly. The concentrations of OPEs in UK foodstuffs were generally of the same order of magnitude as those reported for other countries and our estimates of dietary exposure were well below the corresponding health-based limit values.
Topics: Adult; Aged; Animals; Chickens; China; Diet; Dioxins; Edible Grain; Environmental Monitoring; Esters; Flame Retardants; Humans; Organophosphates; Pesticides; Risk Assessment; United Kingdom
PubMed: 36116644
DOI: 10.1016/j.scitotenv.2022.158368 -
International Journal of Molecular... Oct 2022Dimethylallyl diphosphate (DMAPP) is a key intermediate metabolite in the synthesis of isoprenoids and is also the prenyl donor for biosynthesizing prenylated...
Dimethylallyl diphosphate (DMAPP) is a key intermediate metabolite in the synthesis of isoprenoids and is also the prenyl donor for biosynthesizing prenylated flavonoids. However, it is difficult to prepare DMAPP via chemical and enzymatic methods. In this study, three promiscuous kinases from (SfPK), (EcPK), and (ScPK) and three isopentenyl phosphate kinases from (MtIPK), str. Delta H (MthIPK), and (AtIPK) were cloned and expressed in . The enzymatic properties of recombinant enzymes were determined. The value of SfPK for DMA was 6875 s M, which was significantly higher than those of EcPK and ScPK. The value of MtIPK for DMAP was 402.9 s M, which was ~400% of that of MthIPK. SfPK was stable at pH 7.0-9.5 and had a 1 h half-life at 65 °C. MtIPK was stable at pH 6.0-8.5 and had a 1 h half-life at 50 °C. The stability of SfPK and MtIPK was better than that of the other enzymes. Thus, SfPK and MtIPK were chosen to develop a one-pot enzymatic cascade for producing DMAPP from DMA because of their catalytic efficiency and stability. The optimal ratio between SfPK and MtIPK was 1:8. The optimal pH and temperature for the one-pot enzymatic cascade were 7.0 and 35 °C, respectively. The optimal concentrations of ATP and DMA were 10 and 80 mM, respectively. Finally, maximum DMAPP production reached 1.23 mM at 1 h under optimal conditions. Therefore, the enzymatic method described herein for the biosynthesis of DMAPP from DMA can be widely used for the synthesis of isoprenoids and prenylated flavonoids.
Topics: Phosphates; Hemiterpenes; Escherichia coli; Organophosphates; Terpenes; Flavonoids
PubMed: 36361694
DOI: 10.3390/ijms232112904 -
PLoS Biology Oct 2022ATP is universally conserved as the principal energy currency in cells, driving metabolism through phosphorylation and condensation reactions. Such deep conservation...
ATP is universally conserved as the principal energy currency in cells, driving metabolism through phosphorylation and condensation reactions. Such deep conservation suggests that ATP arose at an early stage of biochemical evolution. Yet purine synthesis requires 6 phosphorylation steps linked to ATP hydrolysis. This autocatalytic requirement for ATP to synthesize ATP implies the need for an earlier prebiotic ATP equivalent, which could drive protometabolism before purine synthesis. Why this early phosphorylating agent was replaced, and specifically with ATP rather than other nucleoside triphosphates, remains a mystery. Here, we show that the deep conservation of ATP might reflect its prebiotic chemistry in relation to another universally conserved intermediate, acetyl phosphate (AcP), which bridges between thioester and phosphate metabolism by linking acetyl CoA to the substrate-level phosphorylation of ADP. We confirm earlier results showing that AcP can phosphorylate ADP to ATP at nearly 20% yield in water in the presence of Fe3+ ions. We then show that Fe3+ and AcP are surprisingly favoured. A wide range of prebiotically relevant ions and minerals failed to catalyse ADP phosphorylation. From a panel of prebiotic phosphorylating agents, only AcP, and to a lesser extent carbamoyl phosphate, showed any significant phosphorylating potential. Critically, AcP did not phosphorylate any other nucleoside diphosphate. We use these data, reaction kinetics, and molecular dynamic simulations to infer a possible mechanism. Our findings might suggest that the reason ATP is universally conserved across life is that its formation is chemically favoured in aqueous solution under mild prebiotic conditions.
Topics: Acetyl Coenzyme A; Adenosine Diphosphate; Adenosine Triphosphate; Carbamyl Phosphate; Diphosphates; Kinetics; Nucleosides; Organophosphates; Water
PubMed: 36194581
DOI: 10.1371/journal.pbio.3001437 -
Environment International Jan 2021The ubiquity of organophosphate esters (OPEs) in various environmental matrices inevitably pose human exposure risks. Numerous studies have investigated human exposure... (Review)
Review
The ubiquity of organophosphate esters (OPEs) in various environmental matrices inevitably pose human exposure risks. Numerous studies have investigated human exposure pathways to OPEs, including air inhalation, dust ingestion, dermal contact, and dietary and drinking water intake, and have indicated that indoor dust and indoor air routes are frequently the two main human exposure pathways. This article reviews the literature on OPE contamination in indoor air and dust from various microenvironments and on OPE particle size distributions and bioavailability in dust conducted over the past 10 years. Ways in which sampling strategies are related to the uncertainty of exposure assessment results and comparability among different studies in terms of sampling tools, sampling sites, and sample types are addressed. Also, the associations of OPEs in indoor dust/air with human biological samples were summarized. Studies on two emerging matrices, hand wipes and silicone wristbands, are demonstrated to be more comprehensive and accurate in reflecting personal human exposure to OPEs in microenvironments and are summarized. Given the direct application of some diester OPEs (di-OPEs) in numerous products, research on their existence in indoor dust and food and on their effects on human urine are also discussed. Finally, related research trends and avenues for future research are prospected.
Topics: Air Pollution, Indoor; China; Dust; Environmental Exposure; Environmental Monitoring; Esters; Flame Retardants; Humans; Organophosphates; Silicones
PubMed: 33395927
DOI: 10.1016/j.envint.2020.106261 -
Environment International Oct 2020Tris(1,3-dichloro-2-propyl)phosphate (TDCPP) is a halogen-containing organophosphorus chemical that is widely employed in various consumer products with a high... (Review)
Review
Tris(1,3-dichloro-2-propyl)phosphate (TDCPP) is a halogen-containing organophosphorus chemical that is widely employed in various consumer products with a high production volume. As an additive flame retardant (FR), TDCPP tends to be released into the environment through multiple routes. It is ubiquitous in environmental media, biotic matrixes, and humans, and thus is deemed to be an emerging environmental contaminant. To date, significant levels of TDCPP and its primary diester metabolite, bis(1,3-dichloro-2-propyl)phosphate, have been detected in human samples of seminal plasma, breast milk, blood plasma, placenta, and urine, thereby causing wide concern about the potential human health effects resulting from exposure to this chemical. Despite the progress in research on TDCPP over the past few years, we are still far from fully understanding the environmental behavior and health risks of this emerging contaminant. Thus, this paper critically reviews the environmental occurrence, exposure, and risks posed by TDCPP to organisms and human health among the literature published in the last decade. It has been demonstrated that TDCPP induces acute-, nerve-, developmental-, reproductive-, hepatic-, nephron-, and endocrine-disrupting toxicity in animals, which has caused increasing concern worldwide. Simultaneously, TDCPP induces cytotoxicity by increasing the formation of reactive oxygen species and inducing endoplasmic reticulum stress in multiple human cell lines in vitro, and also causes endocrine-disrupting effects, including reproductive dysfunction and adverse pregnancy outcomes, according to human epidemiology studies. This review not only provides a better understanding of the behavior of this emerging contaminant in the environment, but also enhances the comprehension of the health risks posed by TDCPP exposure to ecosystems and humans.
Topics: Animals; Ecosystem; Female; Flame Retardants; Humans; Organophosphates; Organophosphorus Compounds; Phosphates
PubMed: 32663715
DOI: 10.1016/j.envint.2020.105946 -
Environmental Health : a Global Access... Jan 2022Previous studies show evidence for associations of prenatal exposure to organophosphate (OP) pesticides with poorer childhood neurodevelopment. As children grow older,...
INTRODUCTION
Previous studies show evidence for associations of prenatal exposure to organophosphate (OP) pesticides with poorer childhood neurodevelopment. As children grow older, poorer cognition, executive function, and school performance can give rise to risk-taking behaviors, including substance abuse, delinquency, and violent acts. We investigated whether prenatal OP exposure was associated with these risk-taking behaviors in adolescence and young adulthood in a Mexican American cohort.
METHODS
We measured urinary dialkyl phosphates (DAPs), non-specific metabolites of OPs, twice (13 and 26 weeks gestation) in pregnant women recruited in 1999-2000 in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study, a birth cohort set in a primarily Latino agricultural community in the Salinas Valley, California. We followed up children throughout their childhood and adolescence; at the 18-year visit, adolescent youth (n = 315) completed a computer-based questionnaire which included questions about substance use, risky sexual activity, risky driving, and delinquency and police encounters. We used multivariable models to estimate associations of prenatal total DAPs with these risk-taking behaviors.
RESULTS
The prevalence of risk-taking behaviors in CHAMACOS youth ranged from 8.9% for smoking or vaping nicotine to 70.2% for committing a delinquent act. Associations of total prenatal DAPs (geometric mean = 132.4 nmol/L) with risk-taking behavior were generally null and imprecise. Isolated findings included a higher risk for smoking or vaping nicotine within the past 30 days (relative risk [RR] per 10-fold increase in prenatal DAPs = 1.89, 95% CI: 1.00, 3.56) and driving without a license (RR = 1.74, 95% CI: 1.25, 2.42). There were no consistent differences by sex or childhood adversity.
DISCUSSION
We did not find clear or consistent evidence for associations of prenatal OP exposure with risk-taking behaviors in adolescence/early adulthood in the CHAMACOS population. Our small sample size may have prevented us from detecting potentially subtle associations of early life OP exposure with these risk-taking behaviors.
Topics: Adolescent; Adult; Child; Environmental Exposure; Female; Humans; Organophosphates; Pesticides; Pregnancy; Prenatal Exposure Delayed Effects; Risk-Taking; Young Adult
PubMed: 35012551
DOI: 10.1186/s12940-021-00822-y -
Environmental Pollution (Barking, Essex... Apr 2024Organophosphate triesters (tri-OPEs) have found substantial use as plasticizers and flame retardants in commercial and industrial products. Despite upcoming potential... (Review)
Review
Organophosphate triesters (tri-OPEs) have found substantial use as plasticizers and flame retardants in commercial and industrial products. Despite upcoming potential restrictions on use of OPEs, widespread environmental contamination is likely for the foreseeable future. Organophosphate diesters (di-OPEs) are known biotic or abiotic degradation products of tri-OPEs. In addition, direct use of di-OPEs as commercial products also contributes to their presence in the atmosphere. We review the available data on contamination with tri-OPEs and di-OPEs in both indoor and outdoor air. Concentrations of tri-OPEs in indoor air exceed those in outdoor air. The widespread discovery of tri-OPE traces in polar regions and oceans is noteworthy and is evidence that they undergo long-range transport. There are only two studies on di-OPEs in outdoor air and no studies on di-OPEs in indoor air until now. Current research on di-OPEs in indoor and outdoor air is urgently needed, especially in countries with potentially high exposure to di-OPEs such as the UK and the US. Di-OPE concentrations are higher at e-waste dismantling areas than at surrounding area. We also summarise the methods employed for sampling and analysis of OPEs in the atmosphere and assess the relative contribution to atmospheric concentrations of di-OPEs made by environmental degradation of triesters, compared to the presence of diesters as by-products in commercial triester products. Finally, we identify shortcomings of current research and provide suggestions for future research.
Topics: Organophosphates; Environmental Exposure; Environmental Monitoring; Flame Retardants; Atmosphere; Esters; China
PubMed: 38402940
DOI: 10.1016/j.envpol.2024.123653 -
Ecotoxicology and Environmental Safety Mar 2023Exposure to organophosphate esters (OPEs) during pregnancy has been suggested to be associated with adverse pregnancy and birth outcomes. However, relevant... (Review)
Review
Exposure to organophosphate esters (OPEs) during pregnancy has been suggested to be associated with adverse pregnancy and birth outcomes. However, relevant investigations are scarce, and the findings are inconsistent. We aimed to conduct a scoping review to provide an overview of these associations. Electronic databases, including MEDLINE (through PubMed), Web of Science, and CNKI (China National Knowledge Infrastructure), were searched from inception to March 2022 and updated in July 2022. A total of 8 studies (1860 participants) were included. Limited evidence indicates that OPE exposure during pregnancy may be negatively associated with both maternal and neonatal triiodothyronine and tetraiodothyronine concentrations but positively associated with thyroid-stimulating hormone concentrations. OPE exposure during pregnancy may be associated with lower insulin concentrations. OPE exposure during pregnancy was associated with gestational age in a sex-specific manner. Intrauterine OPE exposure might increase the risk of preterm birth in female infants but decrease the risk of preterm birth in male infants. Prenatal OPE exposure might be associated with an increased risk of low birth weight. The current scoping review suggests that OPE exposure during pregnancy may disturb pregnancy and birth health, including adverse thyroid function and birth size. Because of the limited evidence obtained for most associations, additional studies followed by a traditional systematic review are needed to confirm these findings.
Topics: Pregnancy; Infant; Humans; Male; Infant, Newborn; Female; Premature Birth; Esters; Infant, Low Birth Weight; Epidemiologic Studies; Organophosphates
PubMed: 36791503
DOI: 10.1016/j.ecoenv.2023.114642 -
Environment International May 2022Alkyl organophosphate flame retardants (OPFRs), tri-n-butyl phosphate (TnBP) and tris(2-butoxyethyl) phosphate (TBOEP), are ubiquitously detected in indoor and outdoor...
Alkyl organophosphate flame retardants (OPFRs), tri-n-butyl phosphate (TnBP) and tris(2-butoxyethyl) phosphate (TBOEP), are ubiquitously detected in indoor and outdoor environments and their inhalation may result in lung damage. This study examined pulmonary toxicity after exposure to TnBP or TBOEP and investigated aggravation of inflammation and immunoreaction by TnBP in an ovalbumin (OVA)-induced mice model. Transcriptomics were used to further reveal the underlying mechanism. Exposure to TnBP or TBOEP resulted in pathological damage, including edema and thickened alveolar septum. In comparison with the control, enhanced levels of superoxide dismutase (SOD) (p < 0.01 in TnBP (High) group and p < 0.05 in TBOEP (High) group), glutathione peroxidase (GSH-px) (p < 0.05), malondialdehyde (MDA) (p < 0.01), and cytokines under a dose-dependent relationship were noted, and the expression of the Fkbp5/Nos3/MAPK/NF-кB signaling pathway (p < 0.01) was upregulated in the TnBP and TBOEP groups. Moreover, the combined exposure of TnBP and OVA exacerbated the allergic inflammatory response, including airway hyperresponsiveness, leukocytosis, cellular exudation and infiltration, secretion of inflammatory mediators, and higher expression of IgE (p < 0.01). Transcriptomics results demonstrated that the PI3K/Akt/NF-кB signal pathway was involved in TnBP-aggravated asthmatic mice. Exposure to TnBP or TBOEP resulted in oxidative damage and leukocyte-induced lung injury. TnBP can further facilitate OVA-induced asthma through an inflammatory response. This study is the first to reveal the pulmonary toxicity and potential mechanism induced by OPFRs through an in-vivo model.
Topics: Animals; Asthma; Flame Retardants; Mice; NF-kappa B; Organophosphates; Ovalbumin; Phosphatidylinositol 3-Kinases; Pneumonia; Signal Transduction
PubMed: 35358787
DOI: 10.1016/j.envint.2022.107209 -
Organic & Biomolecular Chemistry Jan 2020Through the combined action of palladium catalysts and chiral phosphoric acids (CPAs) a variety of catalytic asymmetric reactions have been realized during the past... (Review)
Review
Through the combined action of palladium catalysts and chiral phosphoric acids (CPAs) a variety of catalytic asymmetric reactions have been realized during the past decade, including allylation, alkene functionalization, and C-H activation. This review surveys key examples across these various reaction types and examines the different mechanisms by which CPAs can affect stereoinduction in these reaction systems.
Topics: Catalysis; Organic Chemicals; Organophosphates; Palladium; Stereoisomerism
PubMed: 31907504
DOI: 10.1039/c9ob02205h