A hydrolytic reporter of copper(II) availability in artificial liposomes
摘要:
The dioctadecyl ammonium surfactant 1, functionalized with a p-nitrophenyl ester of picolinic acid, has been synthesized and its hydrolysis in covesicular blends of nonfunctional surfactants dihexadecyldimethylammonium bromide, 3, dioctadecyldimethylammonium bromide, 4, and racemic 1,2-bis(palmitoyloxy)-3-(trimethylammonium)propyl bromide, 5, studied after addition of Cu(II) ions at pH = 5.0 and different temperatures. The cleavage of 1 gives the p-nitrophenoxide surfactant 2, which shows a strong absorption band at 400 nm. Clear biphasic kinetics were observed for all vesicular systems at a temperature below the gel-to-liquid crystal phase transition temperature (T(c)) of the membrane: the first, faster process (almost-equal-to 60% of the ester cleaved) was associated with the Cu(II)-catalyzed hydrolysis of the exovesicular ester; the slower one (the remaining almost-equal-to 40% of the ester cleaved) was associated with the uncatalyzed hydrolysis of the endovesicular ester. Above T(c) only a monoexponential process was observed. Variable temperature experiments allowed one to conclude that the cationic vesicles studied are totally impermeable to Cu(II) ions either below or above their T(c) which controls the rate of the transbilayer movements of the lipids.
A hydrolytic reporter of copper(II) availability in artificial liposomes
摘要:
The dioctadecyl ammonium surfactant 1, functionalized with a p-nitrophenyl ester of picolinic acid, has been synthesized and its hydrolysis in covesicular blends of nonfunctional surfactants dihexadecyldimethylammonium bromide, 3, dioctadecyldimethylammonium bromide, 4, and racemic 1,2-bis(palmitoyloxy)-3-(trimethylammonium)propyl bromide, 5, studied after addition of Cu(II) ions at pH = 5.0 and different temperatures. The cleavage of 1 gives the p-nitrophenoxide surfactant 2, which shows a strong absorption band at 400 nm. Clear biphasic kinetics were observed for all vesicular systems at a temperature below the gel-to-liquid crystal phase transition temperature (T(c)) of the membrane: the first, faster process (almost-equal-to 60% of the ester cleaved) was associated with the Cu(II)-catalyzed hydrolysis of the exovesicular ester; the slower one (the remaining almost-equal-to 40% of the ester cleaved) was associated with the uncatalyzed hydrolysis of the endovesicular ester. Above T(c) only a monoexponential process was observed. Variable temperature experiments allowed one to conclude that the cationic vesicles studied are totally impermeable to Cu(II) ions either below or above their T(c) which controls the rate of the transbilayer movements of the lipids.
[EN] 3-PHENYL-BENZOFURAN-2-ONE DIPHOSPHATE DERIVATIVES AS STABILIZERS<br/>[FR] DÉRIVÉS DE 3-PHÉNYL-BENZOFURAN-2-ONE DIPHOSPHATE UTILISÉS COMME STABILISANTS
申请人:BASF SE
公开号:WO2019243267A1
公开(公告)日:2019-12-26
The invention relates to a composition comprising an organic material susceptible to oxidative, thermal or light-induced degradation and a compound of formula I-P, I-O or I-M. Further embodiments are a compound of formula I-P, I-O or I-M, a process for protection of the organic material by the compound, the use of the compound against degradation of the organic material, an additive composition comprising the compound, processes for manufacturing the compound and an intermediate involved therein.