encephalartos altensteinii/polysaccharide

Studies of the structure of the polysaccharide gum exudate from Encephalartos friderici-guilielmi (a Cycad) confirmed its resemblance to those from other species of the same genus. Partial acid hydrolysis gave numerous products which showed a strong correlation with those from E. longifolius gum.

Sequential, acid hydrolysis of the gum exudate from Encephalartos longifolius cones gave the neutral disaccharides beta-Gal-(1-->3)-Ara (1), beta-Gal-(1-->3)-Gal, and beta-Gal-(1-->6)-Gal; the triouronic acid beta-GlcA-(1-->6)-beta-Gal-(1-->3)-Ara (2); and the biouronic acids described earlier,

The ultrastructure of the cyanobionts of the greenhouse-grown cycads Cycads circinalis, Ceratozamia mexicana, and Encephalartos villosus was studied. In addition to heterocysts with the typical ultrastructure, the cyanobiont microcolonies also contained altered heterocysts with reduced cell walls,

The ultrastructure of the cyanobionts of the greenhouse-grown cycads Cycas circinalis, Ceratozamia mexicana, and Encephalartos villosus was studied. The cyanobiont microcolonies grown in the intercellular space of the cyanobacterial zone of cortical parenchyma in the cycad coralloid roots contained