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Journal of Environmental Sciences... Dec 2015In this study, a series of polyetherimide/SBA-15: 2-D hexagonal P6mm, Santa Barbara USA (PEI/SBA-15) adsorbents modified by phosphoric ester based surfactants (including...
In this study, a series of polyetherimide/SBA-15: 2-D hexagonal P6mm, Santa Barbara USA (PEI/SBA-15) adsorbents modified by phosphoric ester based surfactants (including tri(2-ethylhexyl) phosphate (TEP), bis(2-ethylhexyl) phosphate (BEP) and trimethyl phosphonoacetate (TMPA)) were prepared for CO2 adsorption. Experimental results indicated that the addition of TEP and BEP had positive effects on CO2 adsorption capacity over PEI/SBA-15. In particular, the CO2 adsorption amount could be improved by around 20% for 45PEI-5TEP/SBA-15 compared to the additive-free adsorbent. This could be attributed to the decrease of CO2 diffusion resistance in the PEI bulk network due to the interactions between TEP and loaded PEI molecules, which was further confirmed by adsorption kinetics results. In addition, it was also found that the cyclic performance of the TEP-modified adsorbent was better than the surfactant-free one. This could be due to two main reasons, based on the results of in situ DRIFT and TG-DSC tests. First and more importantly, adsorbed CO2 species could be desorbed more rapidly over TEP-modified adsorbent during the thermal desorption process. Furthermore, the enhanced thermal stability after TEP addition ensured lower degradation of amine groups during adsorption/desorption cycles.
Topics: Adsorption; Carbon Dioxide; Organophosphates; Polyethyleneimine; Silicon Dioxide; Surface-Active Agents
PubMed: 26702962
DOI: 10.1016/j.jes.2015.04.025 -
Methods in Molecular Biology (Clifton,... 1993
Topics: Base Sequence; Biochemistry; Chemistry, Organic; Chromatography, High Pressure Liquid; Molecular Sequence Data; Molecular Structure; Oligodeoxyribonucleotides; Organophosphates; Thionucleosides
PubMed: 8242138
DOI: 10.1385/0-89603-281-7:207 -
Report on Carcinogens : Carcinogen... 2004
Topics: Animals; Carcinogenicity Tests; Carcinogens; Environmental Exposure; Female; Flame Retardants; Guidelines as Topic; Humans; Male; Mice; Models, Biological; Organophosphates; Rats
PubMed: 21105245
DOI: No ID Found -
Applied Microbiology and Biotechnology Oct 2022A related group of phosphotriesters known as organophosphate flame retardants (OPFRs) has become emerging contaminants due to its worldwide use. The lack of an easily...
A related group of phosphotriesters known as organophosphate flame retardants (OPFRs) has become emerging contaminants due to its worldwide use. The lack of an easily hydrolysable bond renders OPFRs inert to the well-known phosphotriesterases capable of hydrolyzing the neurotoxic organophosphates. An OPFRs phosphotriesterase gene stpte was cloned from plasmid pStJH of strain Sphingopyxis terrae subsp. terrae YC-JH3 and was heterologously expressed in Escherichia coli. The recombinant protein St-PTE was purified and analyzed. St-PTE showed the highest catalytic activity at pH 8.5 and 35 °C. The optimal substrate for St-PTE is triphenyl phosphate, with k/K of 5.03 × 10 M s, two orders of magnitude higher than those of tricresyl phosphate (4.17 × 10 M s), 2-ethylhexyl diphenyl phosphate (2.03 × 10 M s) and resorcinol bis(diphenyl phosphate) (6.30 × 10 M s). St-PTE could break the P-O bond of tri-esters and convert aryl-OPFRs into their corresponding di-ester metabolites, including polymers of resorcinol bis(diphenyl phosphate). Mediated by transposase, the gene of OPFRs phosphotriesterase could be transferred horizontally among closely related strains of Sphingomonas, Sphingobium and Sphingopyxis. KEY POINTS: • St-PTE from Sphingopyxis terrae subsp. terrae YC-JH3 could hydrolyze aryl-OPFRs. • Metabolites of RBDPP hydrolyzed by phosphotriesterase were identified. • St-PTE could hydrolyze the P-O cleavage of dimer and trimer of RBDPP. • Phosphotriesterase genes transfer among Sphingomonadaceae mediated by transposase.
Topics: Biphenyl Compounds; Esters; Flame Retardants; Organophosphates; Phosphates; Phosphoric Triester Hydrolases; Polymers; Recombinant Proteins; Resorcinols; Sphingomonadaceae; Transposases; Tritolyl Phosphates
PubMed: 36107214
DOI: 10.1007/s00253-022-12127-2 -
Deutsche Medizinische Wochenschrift... Jul 1957
Topics: Cholinesterase Inhibitors; Humans; Organophosphate Poisoning; Organophosphates; Organophosphorus Compounds; Phosphates; Suicide
PubMed: 13447611
DOI: 10.1055/s-0028-1116858 -
Angewandte Chemie (International Ed. in... Dec 2021Lysosome-relevant cell death induced by lysosomal membrane permeabilization (LMP) has recently attracted increasing attention. However, nearly no studies show that...
Lysosome-relevant cell death induced by lysosomal membrane permeabilization (LMP) has recently attracted increasing attention. However, nearly no studies show that currently available LMP inducers can evoke immunogenic cell death (ICD) or convert immunologically cold tumors to hot. Herein, we report a LMP inducer named TPE-Py-pYK(TPP)pY, which can respond to alkaline phosphatase (ALP), leading to formation of nanoassembies along with fluorescence and singlet oxygen turn-on. TPE-Py-pYK(TPP)pY tends to accumulate in ALP-overexpressed cancer cell lysosomes as well as induce LMP and rupture of lysosomal membranes to massively evoke ICD. Such LMP-induced ICD effectively converts immunologically cold tumors to hot as evidenced by abundant CD8 and CD4 T cells infiltration into the cold tumors. Exposure of ALP-catalyzed nanoassemblies in cancer cell lysosomes to light further intensifies the processes of LMP, ICD and cold-to-hot tumor conversion. This work thus builds a new bridge between lysosome-relevant cell death and cancer immunotherapy.
Topics: Alkaline Phosphatase; Animals; Antineoplastic Agents; Cell Line, Tumor; Drug Design; HEK293 Cells; Humans; Hydroxyl Radical; Immunogenic Cell Death; Intracellular Membranes; Light; Lysosomes; Mice; Neoplasms; Organophosphates; Permeability
PubMed: 34643312
DOI: 10.1002/anie.202110512 -
Journal of Hazardous Materials Aug 2024Organophosphate esters (OPEs) are widely used commercial additives, but their environmental persistence and toxicity raise serious concerns necessitating associated... (Review)
Review
Organophosphate esters (OPEs) are widely used commercial additives, but their environmental persistence and toxicity raise serious concerns necessitating associated remediation strategies. Although there are various existing technologies for OPE removal, comprehensive screening for them is urgently needed to guide further research. This review provides a comprehensive overview of the techniques used to remove OPEs from soil and water, including their related influencing factors, removal mechanisms/degradation pathways, and practical applications. Based on an analysis of the latest literature, we concluded that (1) methods used to decontaminate OPEs include adsorption, hydrolysis, photolysis, advanced oxidation processes (AOPs), activated sludge processes, and microbial degradation; (2) factors such as the quantity/characteristics of the catalysts/additives, pH value, inorganic ion concentration, and natural organic matter (NOM) affect OPE removal; (3) primary degradation mechanisms involve oxidation induced by reactive oxygen species (ROS) (including •OH and SO•) and degradation pathways include hydrolysis, hydroxylation, oxidation, dechlorination, and dealkylation; (5) interference from the pH value, inorganic ion and the presence of NOM may limit complete mineralization during the treatment, impacting practical application of OPE removal techniques. This review provides guidance on existing and potential OPE removal methods, providing a theoretical basis and innovative ideas for developing more efficient and environmentally friendly techniques to treat OPEs in soil and water.
Topics: Esters; Soil Pollutants; Water Pollutants, Chemical; Environmental Restoration and Remediation; Organophosphates; Water Purification
PubMed: 38889460
DOI: 10.1016/j.jhazmat.2024.134834 -
Ecotoxicology and Environmental Safety Dec 2023Organophosphorus flame retardants (OPFRs) have been shown to be carcinogenic, neurotoxic, and endocrine disruptive, so it is important to understand the levels of OPFRs...
Organophosphorus flame retardants (OPFRs) have been shown to be carcinogenic, neurotoxic, and endocrine disruptive, so it is important to understand the levels of OPFRs in human body as well as the modes of external exposure. In this study, we investigated the levels of 13 OPFRs and 7 phosphodiester metabolites in paired human blood and urine, as well as the influencing factors (region, age and gender), and studied the relationship between OPFRs and oxidative stress by urinary metabolites. We found that the concentrations of triphenyl phosphate (TPhP) and tris-(2-ethylhexyl) phosphate (TEHP) in the blood of urban populations were higher than those of rural populations, and that younger populations suffered higher TPhP and 2-ethylhexyl diphenyl phosphate (EHDPP) exposures than older populations. In addition, we found that tris-(2-chloroethyl) phosphate (TCEP), tributyl phosphate (TnBP), TPhP and EHDPP exposure induced oxidative stress. The results of the internal load principal component analysis indicated that dust ingestion, skin exposure, respiration and dietary intake may be the most important sources of TCEP, tris(2-butoxyethyl) phosphate (TBOEP), tri(2-chloroisopropyl) phosphate (TCIPP) and TEHP, respectively, and dust ingestion and skin exposure may be the main sources of TPhP for humans.
Topics: Humans; Flame Retardants; Organophosphorus Compounds; Organophosphates; Dust; Phosphates
PubMed: 37979363
DOI: 10.1016/j.ecoenv.2023.115696 -
Journal of the American Chemical Society Apr 2017Huntington's disease is a neurodegenerative disorder associated with the expansion of the polyglutamine tract in the exon-1 domain of the huntingtin protein (htt). Above...
Huntington's disease is a neurodegenerative disorder associated with the expansion of the polyglutamine tract in the exon-1 domain of the huntingtin protein (htt). Above a threshold of 37 glutamine residues, htt starts to aggregate in a nucleation-dependent manner. A 17-residue N-terminal fragment of htt (N17) has been suggested to play a crucial role in modulating the aggregation propensity and toxicity of htt. Here we identify N17 as a potential target for novel therapeutic intervention using the molecular tweezer CLR01. A combination of biochemical experiments and computer simulations shows that binding of CLR01 induces structural rearrangements within the htt monomer and inhibits htt aggregation, underpinning the key role of N17 in modulating htt toxicity.
Topics: Bridged-Ring Compounds; Exons; Humans; Huntingtin Protein; Hydrophobic and Hydrophilic Interactions; Molecular Dynamics Simulation; Molecular Structure; Organophosphates; Protein Aggregates
PubMed: 28406616
DOI: 10.1021/jacs.6b11039 -
Biochemistry Mar 2020Organophosphate flame retardants are used to inhibit combustion and increase plasticity in plastics and durable foams. While not neurotoxic, these compounds are...
Organophosphate flame retardants are used to inhibit combustion and increase plasticity in plastics and durable foams. While not neurotoxic, these compounds are potential carcinogens, endocrine disrupters, and developmental toxins. The phosphotriesterase from sp. TCM1 (-PTE) is unique among phosphotriesterase enzymes for its ability to hydrolyze these compounds and its ability to hydrolyze any one of the three different ester bonds within a given substrate. In some cases, the extent of hydrolysis of a methyl ester exceeds that of a -nitrophenyl ester within a single substrate. There is a stereochemical component to this hydrolysis where the two enantiomers of chiral substrates give different product ratios. To investigate the stereoselectivity for the product distribution of -PTE, a series of 24 phosphotriesters were synthesized with all possible combinations of methyl, cyclohexyl, phenyl, and -nitrophenyl esters. Prochiral compounds were made chiral by differential isotopic labeling using a chemo/enzymatic strategy, which allowed the differentiation of hydrolysis for each ester in all but two compounds. The rate equations for this unique enzymatic mechanism were derived; the product ratios were determined for each substrate, and the individual kinetic constants for hydrolysis of each ester within each substrate were measured. The findings are consistent with the rate-limiting step for substrate hydrolysis catalyzed by -PTE being the formation of a phosphorane-like intermediate and the kinetic constants and product ratios being dictated by a combination of transition state energies, inductive effects, and stereochemical constraints.
Topics: Biocatalysis; Biodegradation, Environmental; Environmental Pollutants; Flame Retardants; Hydrolysis; Kinetics; Organophosphates; Phosphoric Triester Hydrolases; Sphingomonadaceae; Stereoisomerism; Substrate Specificity
PubMed: 32167750
DOI: 10.1021/acs.biochem.0c00089