What is the Difference Between Arachidic Acid and Arachidonic Acid?

Arachidic acid and arachidonic acid are two structurally similar fatty acids, but they have different properties and sources:

1. Type of Fatty Acid: Arachidic acid is a saturated fatty acid, while arachidonic acid is a polyunsaturated fatty acid.
2. Essentiality: Arachidic acid is a nonessential fatty acid, meaning the body can synthesize it, while arachidonic acid is an essential fatty acid, which must be obtained from the diet.
3. Molecular Formula: The molecular formula of arachidic acid is C20H40O2, whereas the molecular formula of arachidonic acid is C20H32O2.
4. Molar Mass: The molar mass of arachidic acid is 312.538 g·mol-1, but the molar mass of arachidonic acid is 304.5 g·mol-1.
5. Sources: Arachidic acid is found in vegetable oils, including peanut oil, and is ubiquitous in animal fats. In contrast, arachidonic acid is present in animal foods and is almost absent from plant foods and vegetable oils.
6. Effects: Arachidic acid has the effect of raising total cholesterol, while arachidonic acid has the effect of lowering total cholesterol, blood lipid, and blood glucose. Arachidonic acid is important for the development of the brain and optic nerve, playing a crucial role in improving intelligence and eyesight, and is an essential fatty acid for fetuses and infants.
7. Applications: Arachidic acid is mainly useful in industrial applications, such as the production of detergents, lubricants, and coatings. Arachidonic acid can be made into capsules, drinks, and can also be added to cooking oil and confectionery.

Comparative Table: Arachidic Acid vs Arachidonic Acid

Here is a table comparing the differences between arachidic acid and arachidonic acid:

Arachidic acid is a saturated fatty acid with the molecular formula C20H40O2 and a molar mass of 312.538 g/mol. It is a nonessential fatty acid, meaning it can be synthesized by the body and does not need to be obtained from dietary sources. Arachidic acid has various industrial applications, such as being used in the production of detergents.

On the other hand, arachidonic acid is a polyunsaturated essential fatty acid with the molecular formula C20H32O2 and a molar mass of 304.5 g/mol. It contains four double bonds at positions 5, 8, 11, and 14. Arachidonic acid is present in human and animal fat, liver, glandular organs, brain, and animal phosphatides. It has a boiling point of 169°C and a melting point of -49°C. Arachidonic acid is an essential fatty acid, meaning it cannot be synthesized by the body and must be obtained from dietary sources.