palmitic acid

Palmitic acid[1]
IUPAC name	hexadecanoic acid
Identifiers
CAS number	57-10-3 Y
PubChem	985
SMILES	CCCCCCCCCCCCCCCC(=O)O
Properties
Molecular formula	C16H32O2
Molar mass	256.42 g/mol
Appearance	White crystals
Density	0.853 g/cm3 at 62 °C
Melting point	63-64 °C
Boiling point	351-352 °C[2] 215 °C at 15 mmHg
Solubility in water	Insoluble
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Palmitic acid,CH₃(CH₂)₁₄COOH or hexadecanoic acid in IUPAC nomenclature, is one of the most common saturated fatty acids found in animals and plants. As its name indicates, it is a major component of the oil from palm trees (palm oil and palm kernel oil). The word palmitic is from the French "palmitique", the pith of the palm tree. Palmitic acid was discovered by Edmond Frémy in 1840, in saponified palm oil.^[3] Butter, cheese, milk and meat also contain this fatty acid. ^[4]

Palmitate is a term for the salts or esters of palmitic acid. The palmitate anion is the observed form of palmitic acid at physiological pH.^{[citation needed]}

Biochemistry

Palmitic acid is the first fatty acid produced during lipogenesis (fatty acid synthesis) and from which longer fatty acids can be produced. Palmitate negatively feeds back on acetyl-CoA carboxylase (ACC) which is responsible for converting acetyl-CoA to malonyl-CoA which is used to add to the growing acyl chain, thus preventing further palmitate generation. ^[5]

Reduction of palmitic acid yields cetyl alcohol.

Uses

Derivatives of palmitic acid were used in combination with naphtha during World War II to produce napalm (aluminum naphthenate and aluminum palmitate). ^[6]

The World Health Organization claims there is convincing evidence that dietary intake of palmitic acid increases risk of developing cardiovascular diseases. ^[7] However, possibly less-disinterested studies have shown no ill effect, or even a favorable effect, of dietary consumption of palmitic acid on blood lipids and cardiovascular disease, so that the WHO finding may be deemed controversial.^[8] However, another study showed that palmitic acid has no hypercholesterolaemic effect if intake of linoleic acid is greater than 4.5% of energy. On the other hand, it was shown that, if the diet contains trans fatty acids, the health effects are negative, causing an LDL cholesterol increase and HDL cholesterol decrease. ^[9]

Recently, a long-acting anti-psychotic medication, paliperidone palmitate (marketed as INVEGA Sustenna), used in the treatment of schizophrenia, has been synthesized using the oily palmitate ester as a long-acting release carrier medium when injected intramuscularly. The underlying method of drug delivery is similar to that used with decanoic acid to deliver long-acting depot medication, in particular, neuroleptics such as haloperidol decanoate.

See also

• Retinyl palmitate

References