1,2-Dioleoyl-3-trimethylammonium propane (often abbreviated DOTAP or
18:1TAP) is a di-chain, or gemini,
cationic surfactant. It is most commonly encountered as an active ingredient in certain
fabric softener
A fabric softener (American English) or fabric conditioner (British English) is a conditioner applied to laundry after it has been washed in a washing machine. A similar, more dilute preparation meant to be applied to dry fabric is known as a wrin ...
s. The pure material can also be used for the liposomal-
transfection
Transfection is the process of deliberately introducing naked or purified nucleic acids into eukaryotic cells. It may also refer to other methods and cell types, although other terms are often preferred: " transformation" is typically used to des ...
of DNA, RNA and other negatively charged molecules.
Synthesis
The commercial material used for fabric softening is formed by the di-
esterification
In chemistry, an ester is a compound derived from an acid (either organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group () of that acid is replaced by an organyl group (R). These compounds contain a distin ...
of 2,3-epoxypropyltrimethylammoniumchloride (EPTAC) with partially
hydrogenated palm oil
Palm oil is an edible vegetable oil derived from the mesocarp (reddish pulp) of the fruit of oil palms. The oil is used in food manufacturing, in beauty products, and as biofuel. Palm oil accounted for about 36% of global oils produced from o ...
and as such contains a mixture of
fatty acid
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an ...
tails;
palmitic (saturated C16),
stearic (saturated C18),
oleic (monounsaturated C18) and
linoleic (polyunsaturated C18).
In practice the saturated di-sterate compound tend to be the major component of these mixtures.

Material intended for transfection is prepared similarly from high purity oleic acid.
Applications
Fabric softener
It was originally introduced into European markets during the 1990s due to concerns over the environmental effects of
DODAC, which was the principle softener used at the time.
The main difference was the incorporation of cleavable ester groups intended to accelerate its biodegradation. It is a superior softener to di- and
triethanolamine
Triethanolamine, or TEOA, is an organic compound with the chemical formula . It is a colourless, viscous liquid. It is both a tertiary amine and a triol. A triol is a molecule with three alcohol groups. Approximately 150,000 tonnes were produ ...
based softeners but suffers from an increased tendency to hydrolyse. Small
patch test
A patch test is a diagnostic method used to determine which specific substances cause allergic inflammation of a patient's skin.
Patch testing helps identify which substances may be causing a delayed-type allergic reaction in a patient and ...
studies have not shown any clear evidence of it acting is a skin irritant.
Liposomal transfection agent
DOTAP is a cationic surfactant and is able to form stable
cationic liposomes in solution, these readily absorb DNA and other negatively charged organic compounds. The DNA laden liposomes can then be added directly to cell culture medium, where they will combine with the cell membrane and release their payload into the cell.
References
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Quaternary ammonium compounds
Cationic surfactants
Laundry substances