mannuronicé

Mannuronic acid is a uronic acid, a sugar acid derived from mannose. It is a component of alginic acid, a polysaccharide found in brown algae. Alginic acid is a polymer of mannuronic acid and its epimer, guluronic acid. The ratio of these two monomers, as well as their sequence, influences the physical properties of alginic acid, such as its viscosity and ability to form gels.

In nature, alginic acid plays a structural role in the cell walls of brown algae. It contributes to the flexibility and resilience of these organisms, allowing them to withstand the forces of ocean waves. The different arrangements of mannuronic and guluronic acid residues lead to variations in the gelling properties of alginates. For example, alginates with a higher proportion of guluronic acid residues tend to form more rigid gels when cross-linked with divalent cations like calcium.

Mannuronic acid itself can exist in different isomeric forms, depending on the configuration of its chiral centers. Industrially, alginates derived from brown algae are extracted and processed to produce alginic acid and its salts, known as alginates. These alginates have a wide range of applications. They are used as food additives (E400-E404) for thickening, gelling, and stabilizing in products like ice cream, yogurt, and sauces. In the pharmaceutical industry, alginates are used in wound dressings, drug delivery systems, and as an antacid. Their biocompatibility and ability to form hydrogels make them attractive for various biomedical applications.