月桂酸

Lauric acid or systematically, dodecanoic acid, is a saturated fatty acid with a 12-carbon atom chain, thus having many properties of medium-chain fatty acids, is a bright white, powdery solid with a faint odor of bay oil or soap. The salts and esters of lauric acid are known as laurates.

Although 95% of medium-chain triglycerides are absorbed through the portal vein, only 25-30% of lauric acid is absorbed through it.

Like many other fatty acids, lauric acid is inexpensive, has a long shelf-life, is nontoxic, and is safe to handle. It is used mainly for the production of soaps and cosmetics. For these purposes, lauric acid is reacted with sodium hydroxide to give sodium laurate, which is a soap. Most commonly, sodium laurate is obtained by saponification of various oils, such as coconut oil. These precursors give mixtures of sodium laurate and other soaps.

Laboratory Use

In the laboratory, lauric acid may be used to investigate the molar mass of an unknown substance via the freezing-point depression. The choice of lauric acid is convenient because the melting point of the pure compound is relatively high (43.8°C). Its cryoscopic constant is 3.9°C·kg/mol. By melting lauric acid with the unknown substance, allowing it to cool, and recording the temperature at which the mixture freezes, the molar mass of the unknown compound may be determined.

Potential Medicinal Properties

In vitro experiments have suggested that some fatty acids including lauric acid could be a useful component in a treatment for acne, but no clinical trials have yet been conducted to evaluate this potential benefit in humans.

Lauric acid increases total serum cholesterol more than many other fatty acids, but most of the increase is attributable to an increase in high-density lipoprotein (HDL) (the "good" blood cholesterol). As a result, lauric acid has been characterized as having "a more favorable effect on total HDL cholesterol than any other fatty acid [examined], either saturated or unsaturated". In general, a lower total/HDL serum cholesterol ratio correlates with a decrease in atherosclerotic risk. Nonetheless, an extensive meta-analysis on foods affecting the total LDL /serum cholesterol ratio found in 2003 that the net effects of lauric acid on coronary artery disease outcomes remained uncertain. A 2016 review of coconut oil (which is nearly half lauric acid) was similarly inconclusive about the effects on cardiovascular disease risk.

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