VARIATIONS IN THE CONSTITUENT SUGARS OF THE POLYSACCHARIDES FROM NEW-ZEALAND SPECIES OF PACHYMENIA (HALYMENIACEAE)

The nature of the polysaccharides from samples of Pachymenia lusoria, P. laciniata, and P. crassa, together with a sample of P. carnosa for comparison, was examined by means of constituent sugar analyses and C- 13 NMR spectroscopy. We determined that individual P. lusoria extracts were not readily fractionated into distinct chemical entities, and th at the polysaccharides from gametophytic and tetrasporophytic samples of P. lusoria from one site were indistinguishable. Samples of P. luso ria from seven different southern New Zealand locations gave almost id entical polysaccharides (with 2-6% 2-O-methylgalactose) despite being collected at different times of the year and from locations with diffe rent environments. Samples from northern and western waters gave extra cts with distinct chemical differences (e.g. 12-17% 2-O-methylgalactos e) which may fall into two subsets. This suggests that P. lusoria may encompass more than one species. A sample identified as 19 laciniata w as collected from each of two of these geographical areas. The resulta nt polysaccharides were different from each other, but identical to th e extract from Ii lusoria from the corresponding location. No evidence was obtained to support the existence of a northern species previousl y described as P. himantophora, which was reported to contain non-meth ylated polysaccharide similar to xi-carrageenan.