Lauryldimethylamine oxide (LDAO), also known as dodecyldimethylamine oxide (DDAO), is an

amine oxide In chemistry, an amine oxide, also known as an amine ''N''-oxide or simply ''N''-oxide, is a chemical compound that has the chemical formula . It contains a nitrogen-oxygen coordinate covalent bond with three additional hydrogen and/or substitue ...

–based zwitterionic surfactant, with a C₁₂ (dodecyl) alkyl tail. It is one of the most frequently-used surfactants of this type. Like other amine oxide–based surfactants it is

antimicrobial An antimicrobial is an agent that kills microorganisms (microbicide) or stops their growth (bacteriostatic agent). Antimicrobial medicines can be grouped according to the microorganisms they are used to treat. For example, antibiotics are used aga ...

, being effective against common bacteria such as '' S. aureus'' and ''

E. coli ''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escherichia'' that is commonly foun ...

'', however, it is also non-denaturing and can thus be used for

protein purification Protein purification is a series of processes intended to isolate one or a few proteins from a complex mixture, usually Cell biology, cells, Tissue (biology), tissues, or whole organisms. Protein purification is vital for the specification of the ...

. At high concentrations, LDAO forms

liquid crystal Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal can flow like a liquid, but its molecules may be oriented in a common direction as i ...

line phases. Despite having only one polar atom that is able to interact with water – the oxygen atom (the

quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the ...

nitrogen atom is hidden from intermolecular interactions), DDAO is a strongly amphiphilic surfactant: it forms normal

micelle A micelle () or micella () ( or micellae, respectively) is an aggregate (or supramolecular assembly) of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension (also known as associated colloidal system). ...

s and normal liquid crystalline phases. High amphiphilicity of this surfactant can be explained by the fact that it forms not only very strong hydrogen bonds with water: the energy of DDAO – water hydrogen bond is about 50 kJ/mol, but it also has high experimental partition coefficient in non-polar medium, as characterized by experimental logP 5.284

References

{{reflist Amine oxides Surfactants Dodecyl compounds

See also

References