Quaternary ammonium detergents

Balias, N., Zakay, N., Sela, I., and Loyter, A., Liposome bearing a quaternary ammonium detergent as an efficient vehicle for functional transfer of TMV-RNA into plant protoplast, Biochimica et Biophysica Acta, 1988, 939, 8-18. 

Pinnaduwage, P., Schmitt, L., and Huang, L., Use of a quaternary ammonium detergent in liposome mediated DNA transfection of mouse L-cells, Biochimica et Biophysica Acta, 1989, 985, 33-37. 

Avigad and Milner224 used a turbidimetric method based on the measurement of residual turbidity caused by complexing the acid polysaccharide with such quaternary ammonium detergents as cetyl-pyridinium bromide. The activity unit was expressed as the amount of enzyme bringing about a decrease of absorbance at 400 nm of 0.01/min. 

Similar delivery systems have been designed using other cationic polymers, including lipopolyamines (161), amphipathic peptides (162), polylysine lipids (163), cholesterol (164), quaternary ammonium detergents (165), polyamidoamines called dendrimers, polyethylenimines or chitosan, diethylaminoethyl dextran (DEAE dextran), and polybrene. 

This discussion emphasizes the need to understand the nature of the compound to interpret its sorption behavior. Many compounds of environmental significance are nonpolar and one tends to relate sorption to aqueous solubihty. The herbicide, Paraquat, by contrast shows a A oc of 1 x 10 despite having a high aqueous solubility (>600 gL ). This compound is a bipyridinium salt and the high tendency to sorb would be due to cation exchange not partitioning. A comparable response would be expected with quaternary ammonium detergents. 

Valko and DuBois made the interesting observation that bacteria apparently killed by cationic quaternary ammonium detergent germicides may be revived by the addition of a high molecular weight anion, provided that the application of the latter occurs within a period of 10-30 min. 

Palmitic acid (hexadecanoic acid) is the source of the hexadecyl (cetyl) group in the following compounds. Each is a mild surface-acting germicide and fungicide and is used as a topical antiseptic and disinfectant. They are examples of quaternary ammonium detergents, commonly called "quats."... 

Cationic quaternary ammonium compounds such as distearyldimethylammonium-chloride (DSDMAC) used as a softener and as an antistatic, form hydrated particles in a dispersed phase having a similar structure to that of the multilayered liposomes or vesicles of phospholipids 77,79). This liposome-like structure could be made visible by electron microscopy using the freeze-fracture replica technique as shown by Okumura et al. 79). The concentric circles observed should be bimolecular lamellar layers with the sandwiched parts being the entrapped water. In addition, the longest spacings of the small angle X-ray diffraction pattern can be attributed to the inter-lamellar distances. These liposome structures are formed by the hydrated detergent not only in the gel state but also at relatively low concentrations. 

Zjoample Many antiseptics are quaternary ammonium salts ith detergent-like act ion and Benzethonium chloride (11) is particularly efficient. The benzyl group can be added by alkylation of (12) (Chapter T 8) which contains two sets of 1,2-diX relationships. 

Cationic surfactants produce a positively charged surfactant ion in solution and are mainly quaternary nitrogen compounds such as amines and derivatives and quaternary ammonium salts. Owing to their poor cleaning properties, they are little used as detergents rather their use is a result of their bacteriocidal qualities. Relatively little is known about the mechanisms of biodegradation of these compounds. 

Protein False positives may occur with highly buffered or alkaline samples or from contamination with quaternary ammonium compounds (antiseptics, detergents). 

Interpretation of the NMR Spectra of Membranes. Let us first consider a model system of lysolecithin and serum albumin (74), shown in Figure 12. Lysolecithin in D20 is shown in Figure 12A, while the effect of increasing amounts of bovine serum albumin is shown in Figures 12B and 12C. When no protein is present, the lines for both the methylene protons on the lysolipid tails and the quaternary ammonium methyl protons on the choline moiety of the polar heads are narrow. Thus, the polar ends of the molecules are free to move, and the apolar hydrocarbons within the detergent micelles are in a liquid-like state (24). When protein is added, the hydrocarbon proton line broadens and shifts upfield slightly, but neither the width nor area of the quaternary ammonium line... 

Fabric Softening. The single largest market for quaternary ammonium compounds is as fabric softeners. The use of quaternary surfactants as fabric softeners and static control agents can be broken down into three main household product types rinse cycle softeners tumble dryer sheets and detergents containing softeners, also known as softergents. 

The quaternary ammonium compounds (qv) are manufactured by the reaction of an alkyl halide with a tertiary amine. The alkyl halide may be short-chain, long-chain, or benzyl. Selection of a long-chain alkyl group yields structures with variable composition and greatly adds to the chemical complexity inherent in this group. Investigation of structure-activity relationships has led to claims for superior efficacy or compatibility, most notedly with anionic surfactants in disinfectant-detergent cleaner systems, of closely related compounds in the family. 

Surfactants, emulsifiers Dissolve lipids, disrupt membranes, denature proteins, and inactivate enzymes in high concentrations, and act as wetting agents Cationic detergents are used to sanitize utensils, anionic detergents are used to launder clothes and clean household objects, and quaternary ammonium compounds are sometimes used as an antiseptic on skin... 

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