Evidence for the Formation of Acylated or Phosphorylated Monoperoxyphthalates in the Catalytic Esterolytic Reactions in Cationic Surfactant Aggregates

Abstract

Monoperoxyphthalate (MPP) was solubilized in three different aqueous cationic surfactant aggregates composed of (i) a micellar cetyltrimethylammonium chloride (CTACl) solution; (ii) an oil-in-water (O/W) microemulsion (ME) stabilized by CTACl, and a cosurfactant, tert-butyl alcohol, and (iii) a vesicular medium composed of dispersions of dihexadecyldimethylammonium chloride (DHDAC). At pH approximately 8.5 and 25 degrees C, each of these formulations was used to cleave p-nitrophenyl diphenyl phosphate (PNPDPP). The aggregate and the maximum pseudo-first-order rate constants ([MPP] = 4 x 10(-)(5) M, and [PNPDPP] = 1 x 10(-)(5) M) for the PNPDPP cleavages are the following: buffer alone, 0.00034 s(-)(1); micelle: 0.024 s(-)(1); ME: 0.0048 s(-)(1); and vesicle: 0.025 s(-)(1). Importantly all the catalytic formulations showed "turnover" behavior in the presence of excess substrates. By the combined use of (1)H- and (31)P-NMR spectrometry and synthesis, it was possible to provide evidence for the formation of acylated or phosphorylated monoperoxypthalates in the catalytic hydrolyses in cationic surfactant aggregates.

Synthesis and Vesicle Formation from Dimeric Pseudoglyceryl Lipids with (CH2)m Spacers: Pronounced m-Value Dependence of Thermal Properties, Vesicle Fusion, and Cholesterol Complexation

“…3,H 12.07,N 2.05;found C 69.58,H 12.36, 3.30 ± 3.50 (m,20 H,N (CH 3 ) 2 , alkyl chain OCH 2 ), 3.58 ± 3.62 (m,4 H,OCH 2 ),3.65 ± 3.67 (m,2 H,OCH),3.70 ± 4.10 (m,8 H,CH H 12.1,N 2.05;found C 69.68,H 12.17, H 12.12,N 2.03;found C 69.72,H 12.19, H 12.25,N 1.91;found C 70.53,H 12.48, 3.38 ± 3.50 (m,20 H,N (CH 3 ) 2 , alkyl chain OCH 2 ), 3.58 (apparent d,4 H,OCH 2 ),3.60 ± 4.30 (several m,10 H,CH 2 NCH 2 , OCH); C 90 H 186 N 2 O 4 Br 2 (1520.29): calcd C 71. 10,H 12.33,N 1.84;found C 71.37,H 12.23, H 12.40,N 1.78;found C 71.76,H 12.42, H 12.44, N 1.75; found C 71.97, H 12.36, N 1.52.…”

“…[10] Now we turn our attention to synthetic gemini pseudoglyceryl lipids 2. The presence of an intervening À(CH 2 ) m À spacer at the headgroup was found to strongly influence the properties of these lipids at the membrane level.…”

Action de l'Acide Perpropionique sur le Phosphate de Diphenyle et de p -Nitrophenyle. Destruction et Etude du Mecanisme D'Hydrolyse en Phase Aqueuse Micellaire

“…Selon les auteurs, la deuxièmeétape diffère quantà la nature des produits d'hydrolyse età la formation préférentielle de l'anion carboxylate RCO 2,12,13 ou de l'anion percarboxylate RCO 3, 14 Ilétait intéressant d'étudier la formation de l'intermédiaire de la réaction d'hydrolyse du PNPDPP par l'acide perpropionique en milieu micellaire (CTACl) afin de connaître la nature et l'évolution de cet intermédiaire selon l'une des deux voies décrites dans le Schéma 2. * * Uneétude par spectrométrie de masse de la réaction de déphosphorylation du PN-PDPP (0.1 mol L −1 ) par l'acide perpropionique (0.05 mol L −1 ) en milieu micellaire CTACl (0.01 mol L −1 )à pH ∼ 7 a permis d'observer très minoritairement du phosphate d'éthyle et de diphényle [(PhO) 2 P(O)OCH 2 CH 3 ] (<5%) dans le résidu réactionnel.…”

Micellar‐accelerated hydrolysis of organophosphate and thiophosphates by pyridine oximate

“…The investigation of the α‐nucleophiles for the detoxification of organophosphorus pesticides has received major attention due to their superior reactivity as compared to normal nucleophiles. Oximes because of their α‐effect nucleophilic reactivity and a proficient approach to weaken toxicity are used as antidotes for the reactivation of organophosphorus pesticides . Phosphate esters, for the most part mono‐ and diesters, are ever‐present in nature and are fundamental segments of coenzymes, hereditary materials, vitality repositories, and so on.…”