| Alginic acid is a linear 1,4-linked block copolymer comprised of b-D-mannuronic acid (M) and a-L-guluronic acid (G) residues. We offer alginate products from a variety of natural sources, in different purity grades (flocculant, technical to food and high purity pharmaceutical grades) and with different mannuronate/ guluronate ratios and compositions. Alginates with high G content display the strongest gel-forming ability, based on its diaxial conformation compared to the diequatorial linkage in polyM sequences. Typical M: G ratios for alginates from different biological sources may vary from 1.40-1.95 to 0.45-1.00, with high “G” alginates containing up to 69% G residues compared to ~38-41% for regular alginates. The alginate from brown seaweed Macrocystis pyrifera, for instance has18% polyG segments, 41% polyM segments and 42% mixed G/M segments, whilst Laminaria hyperborean alginate has 61% polyG segments, 13% polyM segments and 27% mixed G/M segments. In addition, epimerases may be employed to alter alginate monosaccharides composition. Some 200 grades of alginic acid and its various salts are manufactured for use in the food, textile, paper, water treatment, and pharmaceuticals industries. Alginates are used for a variety of special applications, such as cell immobilization (1), wound dressings (2), antacids (3), pharmaceutical excipients (4), and for drug delivery (5). We offer a wide range of alginates, and can supply alginate beads and fibers on a special request basis. Please call for details and pricing. |
