- Small angle neutron scattering and viscosity studies of micellar solutions of bis-cationic surfactants containing hydroxyethyl methyl quaternary ammonium head groups
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The effect of head group polarity and spacer chain length of bis-cationic surfactants on shape, size and rheology of surfactant aggregates in aqueous solution has been investigated through small angle neutron scattering (SANS) and viscosity measurements. A series of bis-cationic surfactants C 12H25N+(CH3)(C2H 4OH)-(CH2)s-N+(CH 3)(C2H4OH)C12H25 2Br -, referred to as 12-S-12 MEA, where two highly polar quaternary amine centers are covalently connected through polymethylene spacers at head group level, has been synthesized and characterized. Critical micellar concentration of these surfactants in aqueous solution determined by tensiometry and conductometry was observed to be 10-100 times lower than conventional bis-cationic surfactants [C12H25N+(CH 3)2-(CH2)s-N+(CH 3)2C12H25 2Br-, referred to as 12-S-12 DMA]. The extent of aggregate growths and variation in shape and size of micelles was observed to be strongly dependent upon head group polarity, spacer chain length and experimental conditions such as concentration and temperature.
- Borse, Mahendra,Sharma, Vikas,Aswal,Pokhriyal, Naveen K.,Joshi, Jayant V.,Goyal, Prem S.,Devi, Surekha
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- CO2/N2-H2O2 dual-stimulation response surfactant and preparation method thereof
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The invention discloses a CO2/N2-H2O2 dual-stimulation response surfactant and a preparation method thereof. CO2 is introduced to a surfactant to form a bicarbonate cationic surfactant, N2 is introduced to decompose the surfactant to lose surface activity, H2O is added to the surfactant to oxidize in order to form a selenium oxide, vitamin C is added to reduce the selenium oxide into the initial surfactant, so the surfactant has CO2/N2-H2O2 dual-stimulation responsiveness.
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Paragraph 0021; 0022
(2016/12/07)
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- Trifluoromethyl ketone analogs as selective cPLA2 inhibitors
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Selective inhibitors of the cPLA2enzymes are provided which are of use in controlling a wide variety of inflammatory diseases. The inhibitors of the present invention have the general formula where (R′), p, D, Y, Z, Ra, Rband A are as defined in the specification.
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- Trifluoromethyl ketone analogs as selective cPLA2 inhibitors
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Selective inhibitors of the cPLA2enzymes are provided which are of use in controlling a wide variety of inflammatory diseases. The inhibitors of the present invention have the general formula
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- Antimalarial activity of molecules interfering with Plasmodium falciparum phospholipid metabolism. Structure-activity relationship analysis
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A series of 80 compounds, primary, secondary, and tertiary amines and quaternary ammonium and bisammonium salts, most of them synthesized as potential choline or ethanolamine analogs, were tested against the in vitro growth of Plasmodium falciparum, the human malaria parasite. They were active over the 10-3-10-8 M concentration range. A structure-activity relationship study was carried out using autocorrelation vectors as structural descriptors, and multidimensional analysis. Principal component analysis, ascending hierarchical classification, and stepwise discriminant analysis showed that both the size and shape of the molecule were essential for antimalarial potency, making the lipophilicity and electronegativity distribution in the molecular space essential. Using the autocorrelogram describing the molecular shape and the electronegativity distribution on the molecular graph, 98% of the molecules were correctly classified either as poorly active or active with only three explanatory variables. The most active compounds were quaternary ammoniums salts whose nitrogen atom had only one long lipophilic chain of 11 or 12 methylene groups (E5, E6, E10, E13, E20, E21, E22, E23, F4, F8), or the bisammoniums whose polar heads were linked by linear alkyl chains of 10 to 12 carbon atoms (G4, G23). The hydroxyethyl group of choline was not very beneficial, whereas the charge and substitutions of nitrogen (aimed at increasing lipophilicity) were essential for optimal interactions. A crude topographic model of the ligand (choline) binding site was thus drawn up.
- Calas, Michèle,Cordina, Gérard,Bompart, Jacques,Bari, Mohamed Ben,Jei, Ta?b,Ancelin, Marie L.,Vial, Henri
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p. 3557 - 3566
(2007/10/03)
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