- Synthesis, self-aggregation and biological properties of alkylphosphocholine and alkylphosphohomocholine derivatives of cetyltrimethylammonium bromide, cetylpyridinium bromide, benzalkonium bromide (C16) and benzethonium chloride
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A series of alkylphosphocholine and alkylphosphohomocholine derivatives of cetyltrimethylammonium bromide, cetylpyridinium bromide, benzalkonium bromide (C16) and benzethonium chloride have been synthesized. Their physicochemical properties were also investigated. The critical micelle concentration (cmc), the surface tension value at the cmc (γcmc), and the surface area at the surface saturation per head group (Acmc) were determined by means of surface tension measurements. The prepared compounds exhibit significant cytotoxic, antifungal and antiprotozoal activities. Alkylphosphocholines and alkylphosphohomocholines possess higher antifungal activity against Candida albicans in comparison with quaternary ammonium compounds in general. However, quaternary ammonium compounds exhibit significantly higher activity against human tumor cells and pathogenic free-living amoebae Acanthamoeba lugdunensis and Acanthamoeba quina compared to alkylphosphocholines. The relationship between structure, physicochemical properties and biological activity of the tested compounds is discussed.
- Luká?, Milo?,Mrva, Martin,Garajová, Mária,Moj?i?ová, Gabriela,Varinská, Lenka,Moj?i?, Ján,Sabol, Marián,Kubincová, Janka,Haragová, Hana,Ondriska, Franti?ek,Devínsky, Ferdinand
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- Synthesis, characterization and conductivity of quaternary nitrogen surfactants modified by the addition of a hydroxymethyl substructure on the head group
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Two novel series of hydroxymethyl group-appended quaternary nitrogen surfactants (QNSs) based on the aliphatic N-alkyl-trimethylammonium and aromatic N-alkylpyridinium head groups were synthesized from the appropriate nitrogen head group precursor and 1-bromoalkane. The QNSs were characterized using 1H and 13C nuclear magnetic resonance and infrared spectroscopy, and their purity confirmed using elemental analysis. The solution behavior of the QNSs was investigated by conductivity, assessing both the aggregation concentration as well as the amount of counter-ion dissociation. The results showed a general decrease in the aggregation concentration for the compounds with the hydroxymethyl addition, where the pyridinium compounds were more affected than the ammonium QNSs. In contrast, the extent of counter-ion dissociation (α) from the aggregate was slightly increased for the ammonium compounds but that of the pyridinium compounds was not generally affected by the structural modification.
- Jordan, Deborah,Tan, Eng,Hegh, Dylan
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p. 587 - 592
(2012/10/29)
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- Preparation of the pyridinium salts differing in the length of the N-alkyl substituent
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Quaternary pyridinium salts with chains ranging from C8 to C20 belong in the large group of cationic surfactants. In this paper, the preparation of such cationic surface active agents based on the pyridinium moiety and differing in the length of the N-alkyl chain is described. Additionally, HPLC technique was established to distinguish each prepared pyridinium analogue. This study represents universal method for preparation and identification of quaternary pyridinium detergents.
- Marek, Jan,Stodulka, Petr,Cabal, Jiri,Soukup, Ondrej,Pohanka, Miroslav,Korabecny, Jan,Musilek, Kamil,Kuca, Kamil
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experimental part
p. 1967 - 1972
(2010/09/08)
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- Synthesis of imidazolium and pyridinium-based ionic liquids and application of 1-alkyl-3-methylimidazolium salts as pre-catalysts for the benzoin condensation using solvent-free and microwave activation
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An efficient one-pot procedure for the synthesis of ionic liquids based on nitrogen-containing heterocycles, imidazolium or pyridinium under 'green chemistry' conditions has been described. Imidazolium salts and DBU have been found to catalyze efficiently the benzoin condensation giving good yields within very short reaction time using solvent-free microwave activation conditions.
- Aupoix, Audrey,Pégot, Bruce,Vo-Thanh, Giang
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experimental part
p. 1352 - 1356
(2010/04/02)
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- Biodegradable pyridinium ionic liquids: Design, synthesis and evaluation
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A range of ionic liquids (ILs) with a pyridinium cation were synthesised and their biodegradability was evaluated using the CO2 Headspace test (ISO 14593). ILs bearing an ester side chain moiety were prepared from either pyridine or nicotinic acid and showed high levels of biodegradation under aerobic conditions and can be classified as 'readily biodegradable'. In contrast, pyridinium ILs with alkyl side chains showed significantly lower levels of biodegradability in the same test. The utility of the biodegradable IL 6c as a reaction solvent for the Diels-Alder reaction was also investigated.
- Harjani, Jitendra R.,Singer, Robert D.,Garcia, M. Teresa,Scammells, Peter J.
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experimental part
p. 83 - 90
(2010/04/22)
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- Interaction of Methyl Orange with Submicellar Cationic Surfactants
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The interaction of aqueous Methyl Orange (MO), an azo dye, with alkyltrimethylammonium and N-hexadecylpyridinium halide surfactants in submicellar concentration ranges has been investigated.The interaction gives rise to a new absorption band of MO with a maximum at ca. 370 nm, and the appearance of the new band has been attributed to change in the chromophore microenvironment in water structure enforced closely packed ion pairs of the dye with submicellar cationic surfactant.The strength of the interaction depends on the alkyl chain length of the surfactant, the surfactant head group and the counter ions.
- Dutta, Robin K.,Bhat, Subray N.
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p. 2457 - 2460
(2007/10/02)
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- Effect of Alcohols and Oils on the Kinetics of Micelle Formation-Breakdown in Aqueous Solutions of Ionic Surfactants
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The temperature-jump method has been used for an extensive study of the dependence of the relaxation time τ2 characterizing the process of micelle formation-breakdown on the surfactant concentration C and upon additions of alcohols and oils to moderately concentrated surfactant solutions.The 1/τ2 vs.C curves have been found to be V-shaped, as in previous studies.For the four surfactants investigated, the increase of 1/τ2 at high C has been interpreted in terms of rapid coagulation-fragmentation processes postulated by Kahlweit (Kahlweit, M.Pure Appl.Chem. 1981, 53, 2060.J.Colloid Interface Sci. 1982, 90, 92).The changes of τ2 have been found to be very sensitive to the nature, chain length, and concentration of both the added alcohol and oil.Additions of medium chain length alcohols (up to 1-hexanol) increase dramatically 1/τ2 by up to a factor of 104.Additions of oils to mixed surfactant + alcohol micellar solutions result in the opposite effect.Longer chain alcohols behave like medium chain length alcohols at low alcohol concentration and like oils at high alcohol concentration, when they become solubilized in the micelle core.Additional measurements by means of time-resolved fluorescence probing and quasi-elastic light scattering have been performed in order to obtain information on the micelle aggregation number and the micelle size and polydispersity of some of the investigated systems.The observed changes of 1/τ2 upon addition of alcohols and oils have been interpreted in terms of variations of the concentration of the species around the minimum of the size distribution curve and, in turn, in terms of the polydispersity of the systems and its effect on the micelle breakdown-formation, in agreement with the quasi-elastic light-scattering results.The relationship between the present chemical relaxation results on micellar kinetics and those obtained recently by time-resolved fluorescence probing is discussed.
- Lang, Jacques,Zana, Raoul
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p. 5258 - 5265
(2007/10/02)
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- Models for Specific Counterion Effects on the Incorporation of Charged Amphiphilic Substrates into Like-Charged Ionic Micelles
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Data for the quenching of the fluorescence of two anthracene-derived amphiphilic fluorescence probes (ethyldimethyl- (I) and trimethylammonium bromide (II) in aqueous micellar solutions of the quencher detergents N-hexadecylpyridinium chloride (HPCl), bromide (HPBr), and nitrate (HPNO3) are analyzed in terms of a photophysical model which assumes static quenching of the micelle-incorporated probe and dynamic quenching of the residual fluorescence of the unincorporated probe by free detergent monomer and free counterions.This analysis provides values for the ground-state probe incorporation coefficient KS which are compatible with independent estimates based on the quenching of the emission of the micelle-excluded Ru(bpy)32+ ion by I under the same conditions.The results of the present study clearly show that KS for incorporation of a charged amphiphilic substrate into the micellar phase of a like-charged detergent is quite sensitive to the concentration of detergent and added salt present.In addition to this general salt dependence, which can be ascribed to the effects of intermicellar ionic strength and intermicellar interactions on the micellar surface potential, the magnitude of KS also exhibits a significant specific salt (counterion) dependence.Consideration of the consequences of selectivity in counterion exchange at the micelle surface on the effective micellar surface potential provides an analytical expression which rationalizes the obseved specific counterion effects on KS for this type of substrate.The implications for the quantitative analysis of ground-state reactions and equilibria in ionic micellar solution are pointed out and methods for estimating KS under diverse experimental conditions suggested.
- Miola, Laerte,Abakerli, Rosangela Biotta,Ginani, Marconi F.,Filho, Pedro Berci,Toscano, Vicente G.,Quina, Frank H.
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p. 4417 - 4425
(2007/10/02)
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