Structure of an α-D-galactosaminoglycan from Physarum polycephalum Spherule walls

The spherule walls Physarum polucephalum have been reexamined and found to contain 88% of galactosamine (as anhydrogalactosamine), 6.80% of protein, 4.7% of phosphate groups, and a small proportion of acetyl groups (0.5%). Methylation studies indicated that the spherule-wall polysaccharide is a long-chain galactosamino- glycan linked exclusively (1→4) and without phosphate linkages. The specific optical rotation of this unique glycan. [x]_D, + 118° (6_M HCI), indicated that it is α-D-linked.