Hydrolytic Dephosphorylation of p- Nitrophenyl Diphenyl Phosphate by Alkyl Hydroxamate Ions

2018 ◽  
Vol 21 (2) ◽  
pp. 209-220
Author(s):  
Neha Kandpal ◽  
Hitesh K. Dewangan ◽  
Rekha Nagwanshi ◽  
Kallol K. Ghosh ◽  
Manmohan L. Satnami
Keyword(s):  
Hydroxamate Ions ◽  
Diphenyl Phosphate

scholarly journals Neurodevelopmental toxicity assessment of flame retardants using a human DNT in vitro testing battery

2021 ◽  
Author(s):  
Jördis Klose ◽  
Melanie Pahl ◽  
Kristina Bartmann ◽  
Farina Bendt ◽  
Jonathan Blum ◽  
...  
Keyword(s):  
Human Cell ◽  
Polybrominated Diphenyl Ethers ◽  
Flame Retardants ◽  
Real Life ◽  
Toxicity Assessment ◽  
Oligodendrocyte Differentiation ◽  
Neurodevelopmental Toxicity ◽  
Diphenyl Phosphate

AbstractDue to their neurodevelopmental toxicity, flame retardants (FRs) like polybrominated diphenyl ethers are banned from the market and replaced by alternative FRs, like organophosphorus FRs, that have mostly unknown toxicological profiles. To study their neurodevelopmental toxicity, we evaluated the hazard of several FRs including phased-out polybrominated FRs and organophosphorus FRs: 2,2′,4,4′-tetrabromodiphenylether (BDE-47), 2,2′,4,4′,5-pentabromodiphenylether (BDE-99), tetrabromobisphenol A, triphenyl phosphate, tris(2-butoxyethyl) phosphate and its metabolite bis-(2-butoxyethyl) phosphate, isodecyl diphenyl phosphate, triphenyl isopropylated phosphate, tricresyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tert-butylphenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, tris(1-chloroisopropyl) phosphate, and tris(2-chloroethyl) phosphate. Therefore, we used a human cell–based developmental neurotoxicity (DNT) in vitro battery covering a large variety of neurodevelopmental endpoints. Potency according to the respective most sensitive benchmark concentration (BMC) across the battery ranked from <1 μM (5 FRs), 1<10 μM (7 FRs) to the >10 μM range (3 FRs). Evaluation of the data with the ToxPi tool revealed a distinct ranking (a) than with the BMC and (b) compared to the ToxCast data, suggesting that DNT hazard of these FRs is not well predicted by ToxCast assays. Extrapolating the DNT in vitro battery BMCs to human FR exposure via breast milk suggests low risk for individual compounds. However, it raises a potential concern for real-life mixture exposure, especially when different compounds converge through diverse modes-of-action on common endpoints, like oligodendrocyte differentiation in this study. This case study using FRs suggests that human cell–based DNT in vitro battery is a promising approach for neurodevelopmental hazard assessment and compound prioritization in risk assessment. Graphical abstract

Dynamics of isopropylphenyl diphenyl phosphate in fathead minnows

Chemosphere ◽  
1983 ◽  
Vol 12 (6) ◽  
pp. 799-807 ◽  
Author(s):  
James N. Huckins ◽  
Jimmie D. Petty
Keyword(s):  
Fathead Minnows ◽  
Diphenyl Phosphate

scholarly journals PHYSICAL CHEMICAL STUDIES OF THE SURFACTANT DILAURYLDIMETHYLAMMONIUM BROMIDE (DLDMAB): AGGREGATION AND CATALYTIC PROPERTIES

2009 ◽  
Vol 17 (17) ◽  
pp. 21-32
Author(s):  
Elizabeth Fatima de Souza ◽  
Silvia Dani ◽  
Lavinel G. IONESCU
Keyword(s):  
Thermodynamic Parameters ◽  
Catalytic Properties ◽  
Activation Parameters ◽  
Critical Micellar Concentration ◽  
Physical Chemical ◽  
Chemical Studies ◽  
Diphenyl Phosphate ◽  
C 32 ◽  
Free Energy Of Micellization ◽  
Hydrolysis Of

The micellization of dilauryldimethylammonium bromide (DLDMAB) in water was studied by using surface tension measurements. The critical micellar concentration (CMC) was determined at 25°C, 32°C and 40°C and thermodynamic parameters such as the free energy of micellization (∆G°mic), enthalpy (∆H°mic), and entropy (∆S°mic) of micellization were measured. The CMC at 25°C was 4.93 x 10-5 M and the corresponding values of the thermodynamic parameters were: ∆G°mic = -5.87 kcal/mol; ∆H°mic = -1.12 kcal/mol and ∆S°mic = +16.00 e.u. Micelles of the surfactant DLDMAB act as catalysts for the alkaline hydrolysis of p-nitrophenyl diphenyl phosphate (NPDPP) with a maximum catalytic factor of approximately 120 compared to 80 for CTAB. Typical activation parameters measured for 1.00 x 10-3 M surfactant and 0.005 M NaOH were: Ea = 9.7 kcal/mo/; ∆H°≠ = 9.1 kcal/mol; ∆G°≠ = 19.6 kcal/mol and ∆S°≠ = -33.9 e.u. The kinetic results were also analyzed in terms of the pseudo-phase ion-exchange models (PPIE) and showed that the model is applicable to describe the experimental results.

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