What Are Fatty Acids?

Posted by beauty33 on April 20th, 2022

Fatty acids (FAs) are organic compounds with long aliphatic hydrocarbon chains and a carboxyl group at one end. As the simplest type of lipid, fatty acids are an important component of other more complex lipids such as neutral fats, phospholipids, and glycolipids.

Classification of fatty acids

According to the degree of saturation, fatty acids can be classified into saturated and unsaturated. Unsaturated fatty acids include monounsaturated fatty acids and polyunsaturated fatty acids.

Saturated fatty acids: fatty acids containing saturated bonds. Excessive intake can easily lead to atherosclerosis and increase the risk of coronary heart disease.

Monounsaturated fatty acids: contain an unsaturated bond and play an important role in reducing cholesterol and triglycerides.

Polyunsaturated fatty acids: According to the position of the double bond, polyunsaturated fatty acids can be divided into Omega-3, Omega-6 and other types. Omega-3 and Omega-6 fatty acids coordinate and restrict each other in function, and they play important roles in the organism as they jointly regulate life activities.

n Omega-3 fatty acids: including linolenic acid, EPA, DHA, etc. DHA can promote fetal brain development. EPA can lower cholesterol and triglycerides and prevent cardiovascular diseases such as atherosclerosis.

n Omega-6 fatty acids: including linoleic acid, gamma-linolenic acid, arachidonic acid, prostaglandins, thromboxanes and leukotrienes. γ-linolenic acid can inhibit lipid peroxidation, reduce vascular endothelial damage, and produce anti-atherosclerosis effects. Arachidonic acid (AA) is a precursor of prostaglandin, thromboxane and leukotriene, which can cause inflammation, vasoconstriction, and promote thrombosis.

According to the spatial structure of carboxylic acids, fatty acids are further divided into cis fatty acids and trans fatty acids.

Function of fatty acids

In the case of sufficient oxygen supply, fatty acids can be oxidized and decomposed into carbon dioxide and water, releasing a large amount of energy, which is one of the main energy sources of the body. Fatty acid β-oxidation is the main way of fatty acid decomposition in the body. Fatty acid oxidation not only provides a large amount of energy for the body but also generates a large amount of acetyl CoA, which is the intermediate raw material for compound synthesis in the body. In addition, fatty acids are necessary for nutrition and are closely related to the occurrence and development of many diseases.

Free fatty acid analysis

Free fatty acids are accounted for only 10% of total fatty acids in biological samples. Since the content of free fatty acids is low and the dynamic fluctuation range is wide, it is challenging to simultaneously detect and quantify as many free fatty acids as possible in biological samples at once. The LC-MS/MS technique can be used to qualitatively and quantitatively determine 70+ free fatty acids in a variety of biological samples. The detection of free fatty acid level can reflect the status of lipid metabolism, glucose metabolism and endocrine function of the body, which can promote the exploration of the pathogenesis and prevention of diseases.