Abstract
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 (Tc) of the membrane: the first, faster process (≈60% of the ester cleaved) was associated with the Cu(II)-catalyzed hydrolysis of the exovesicular ester; the slower one (the remaining ≈40% of the ester cleaved) was associated with the uncatalyzed hydrolysis of the endovesicular ester. Above Tc 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 Tc which controls the rate of the transbilayer movements of the lipids.
| Original language | English |
|---|---|
| Pages (from-to) | 3025-3029 |
| Number of pages | 5 |
| Journal | Journal of Organic Chemistry |
| Volume | 58 |
| Issue number | 11 |
| Publication status | Published - 1993 |
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ASJC Scopus subject areas
- Organic Chemistry
Cite this
A hydrolytic reporter of Cu(II) availability in artificial liposomes. / Ghirlanda, Giovanna; Scrimin, Paolo; Tecilla, Paolo; Tonellato, Umberto.
In: Journal of Organic Chemistry, Vol. 58, No. 11, 1993, p. 3025-3029.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A hydrolytic reporter of Cu(II) availability in artificial liposomes
AU - Ghirlanda, Giovanna
AU - Scrimin, Paolo
AU - Tecilla, Paolo
AU - Tonellato, Umberto
PY - 1993
Y1 - 1993
N2 - 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 (Tc) of the membrane: the first, faster process (≈60% of the ester cleaved) was associated with the Cu(II)-catalyzed hydrolysis of the exovesicular ester; the slower one (the remaining ≈40% of the ester cleaved) was associated with the uncatalyzed hydrolysis of the endovesicular ester. Above Tc 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 Tc which controls the rate of the transbilayer movements of the lipids.
AB - 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 (Tc) of the membrane: the first, faster process (≈60% of the ester cleaved) was associated with the Cu(II)-catalyzed hydrolysis of the exovesicular ester; the slower one (the remaining ≈40% of the ester cleaved) was associated with the uncatalyzed hydrolysis of the endovesicular ester. Above Tc 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 Tc which controls the rate of the transbilayer movements of the lipids.
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M3 - Article
VL - 58
SP - 3025
EP - 3029
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
SN - 0022-3263
IS - 11
ER -