Alginic acid CAS# 9005-32-7

Alginate is a viscous organic acid, also known as fucoidan and alginic acid. The product is a white to light yellowish-brown powder. The average molecular weight is about 240,000. Melting point >300°C. Slightly soluble in hot water, its viscosity in aqueous solution is 4 times higher than that of starch, insoluble in cold water and organic solvents, slowly soluble in alkaline solutions. Odorless. It is widely found in nature in the cell walls of hundreds of brown algae such as macroalgae, kombu, kelp, Murray’s algae, and Sargassum, with a higher content in kombu family algae (about 20% on average), mostly in the form of calcium and magnesium salts. Alginate is a straight-chain block polyglyoxalate consisting of a homopolymerized α-L-Gulo-gulo block, a homopolymerized β-D-mannopyranosylate block, and a crosspolymerised block of these two glyoxalates linked by a 1,4-glycosidic bond. Present in the cell walls of many marine brown algae in the form of calcium, magnesium, sodium, potassium, and strontium salts. Industrially derived from macroalgae, kelp of Kraughtsman, palm kelp, sugar kelp, sea kelp, cuneiform kelp (L. ochotensis), narrow-leaved kelp, vesicular algae (Ascophyllumrodosum), ditch deerstalker, inkhorn algae (Fucusvesiculosus), toothed-edge blackthorn algae, sea, hollow-stemmed kombu and wing algae ( ChemicalbookAlaria). The general extraction method is: the raw seaweed is washed, digested with alkali to produce soluble alkali metal salts, filtered, and acid added to precipitate the fucoid acid. Fucoidan can also be converted into sodium, potassium, ammonium, calcium salts, or other organic derivatives, collectively known as fucoidan (again). Commercial fucoidan mainly refers to sodium fucoidan. Free fucoidan is a white solid. It is insoluble in cold water and slightly soluble in hot water. It is highly acidic and acid-resistant but is easily decomposed by hot bases. Decarboxylation occurs by the action of concentrated hydrochloric acid. It has some selective adsorption for metal ions, especially Fe(II) ions. Its alkali metal salts and ammonium salts dissolve in water to produce a viscous liquid but do not easily produce a gel. Below pH 3 it is converted into insoluble fucoidan gels or precipitates. The addition of multivalent metal ions (e.g. calcium chloride) makes it easy to gel. The sodium salt is a slightly yellow powder, insoluble in organic solvents, [a]D-139°. Fucoidan is widely used in the food, textile printing and dyeing, paper, pharmaceutical, leather, cosmetic, rubber, paint, and water treatment industries. Alginate is mainly used as a raw material for salts such as sodium alginate and the manufacture of drugs such as gastrodia. It is also used as an excipient, binder, and stabilizer for tablets. In food and cosmetics, it is often used as a thickening agent and emulsifier.

Alginate is a viscous organic acid, also known as fucoidan and alginic acid. The product is a white to light yellowish-brown powder. The average molecular weight is about 240,000. Melting point >300°C. Slightly soluble in hot water, its viscosity in aqueous solution is 4 times higher than that of starch, insoluble in cold water and organic solvents, slowly soluble in alkaline solutions. Odorless. It is widely found in nature in the cell walls of hundreds of brown algae such as macroalgae, kombu, kelp, Murray’s algae, and Sargassum, with a higher content in kombu family algae (about 20% on average), mostly in the form of calcium and magnesium salts. Alginate is a straight-chain block polyglyoxalate consisting of a homopolymerized α-L-Gulo-gulo block, a homopolymerized β-D-mannopyranosylate block, and a crosspolymerised block of these two glyoxalates linked by a 1,4-glycosidic bond. Present in the cell walls of many marine brown algae in the form of calcium, magnesium, sodium, potassium, and strontium salts. Industrially derived from macroalgae, kelp of Kraughtsman, palm kelp, sugar kelp, sea kelp, cuneiform kelp (L. ochotensis), narrow-leaved kelp, vesicular algae (Ascophyllumrodosum), ditch deerstalker, inkhorn algae (Fucusvesiculosus), toothed-edge blackthorn algae, sea-, hollow-stemmed kombu and wing algae ( ChemicalbookAlaria). The general extraction method is: the raw seaweed is washed, digested with alkali to produce soluble alkali metal salts, filtered, and acid added to precipitate the fucoid acid. Fucoidan can also be converted into sodium, potassium, ammonium, calcium salts, or other organic derivatives, collectively known as fucoidan (again). Commercial fucoidan mainly refers to sodium fucoidan. Free fucoidan is a white solid. It is insoluble in cold water and slightly soluble in hot water. It is highly acidic and acid-resistant but is easily decomposed by hot bases. Decarboxylation occurs by the action of concentrated hydrochloric acid. It has some selective adsorption for metal ions, especially Fe(II) ions. Its alkali metal salts and ammonium salts dissolve in water to produce a viscous liquid but do not easily produce a gel. Below pH 3 it is converted into insoluble fucoidan gels or precipitates. The addition of multivalent metal ions (e.g. calcium chloride) makes it easy to gel. The sodium salt is a slightly yellow powder, insoluble in organic solvents, [a]D-139°. Fucoidan is widely used in the food, textile printing and dyeing, paper, pharmaceutical, leather, cosmetic, rubber, paint, and water treatment industries. Alginate is mainly used as a raw material for salts such as sodium alginate and the manufacture of drugs such as gastrodia. It is also used as an excipient, binder, and stabilizer for tablets. In food and cosmetics, it is often used as a thickening agent and emulsifier.