Guluronic: mannuronic acid ratios were assessed for the alginates from
11 New Zealand brown seaweeds. The highest contents of guluronic acid
were found in alginates from two seaweeds from the Chordariales, whic
h are mucilaginous, nonrigid and are winter/spring annuals; hence, hig
h levels of guluronic acids do not appear to correlate with either pla
nt rigidity or age. Conversely, the amounts of guluronic acid were hig
hest in the species with the lowest yield of alginate. The percentage
of the lowest uronic acid in the alternating polymer blocks was approx
imately constant within orders but varied between orders.