Mannuronihappoa

Mannuronihappoa, also known as D-mannuronic acid, is a monosaccharide uronic acid. It is a component of alginic acid, a polysaccharide found in the cell walls of brown algae. Mannuronihappoa is an epimer of guluronic acid, meaning they differ in the configuration of one chiral center. In alginic acid, these two uronic acid units are linked together in varying proportions and sequences, which significantly influences the physical properties of the alginate polymer.

The structure of mannuronihappoa consists of a six-carbon chain with a carboxyl group at one end (C1) and a hydroxyl group on the second carbon (C2). The specific stereochemistry at the chiral centers defines it as D-mannuronic acid. It can exist in various ring forms, primarily the pyranose ring.

Mannuronihappoa plays a crucial role in the functionality of alginates. The ratio of mannuronic acid to guluronic acid residues, as well as their arrangement along the polymer chain, determines the gelling properties of alginates. Alginates are widely used in various industries, including food, pharmaceuticals, and biotechnology, due to their gelling ability, viscosity, and biocompatibility. These applications often leverage the ability of mannuronic acid residues within the alginate chain to interact with divalent cations, such as calcium ions, to form stable gel networks. The biosynthesis of mannuronihappoa occurs in brown algae through the epimerization of GDP-mannose.