Porphyra umbilicalis, mannan

Mannans, in which mannose units are linked predominantly in j8-d-(1—>4) bonds, are found in the red seaweed Porphyra umbilicalis, in the seed of the tagua palm (Phytelephas macrocarpa) in the form of massive thickening of the cell walls of the endosperm, and in the endosperm of members of the Umbelliferae and of the Compositae (e.g., lettuce seed). 

Yeast mannan is an amorphous, homogeneous polysaccharide with a D. P. of about 500. The proposed structure of this mannan is a long chain, with radiating side-chains of one or two D-mannopyranose units. In this mannan, 2 —> 1, 3 —> 1, and 6 — 1 linkages have been found. The mannan of the seaweed Porphyra umbilicalis contains chiefly 4 —> 1 /3-d linkages, and is of the branched-chain type with about one branch for each 12 D-mannose residues. 

Mannans yeast mannan, Porphyra umbilicalis Tnafinan... 

The red seaweed Porphyra umbilicalis, which is widely used as a food, contains a predominantly / -d-(i -> 4)-linked mannan along with other polysaccharides (sulfated galactans). The mannan appears to have a branched chain structure with one branch point for every 12 D-mannose residues. 

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