title: Structural analysis of the polysaccharide from Pachymenia lusoria (Cryptonemiaceae, Rhodophyta).
abstract: The highly complex polysaccharide extracted from the New Zealand red alga Pachymenia lusoria (Grev.) J. Ag. has been characterised and certain structural features defined. A reductive hydrolysis procedure was used for constituent sugar and linkage analyses, with trideuteriomethylation being employed to enable the location of natural methyl ether groups to be determined. A reductive partial-hydrolysis procedure allowed agarobiosyl constituent residues to be identified. The analytical results are consistent with the polymer having a linear backbone of 3-linked D-galactopyranosyl alternating with 4-linked D- or L-galactopyranosyl residues. The 3-linked residues are nearly all 2-sulfated, with 1 in 3 also being 6-O-methylated and 1 in 5 also bearing a 4,6-pyruvic acetal residue. About one-third of the polymer is comprised of blocks of agarobiosyl repeat units that are 2-sulfated on the beta-D-galactopyranosyl and one-third 2-O-methylated on the 3,6-anhydro-L-galactosyl constituents. Of the remaining 4-linked residues, half are 2-O-methyl-D-galactopyranosyl residues and half are galactopyranosyl residues, of which approximately half are in the L configuration.
authors.affiliation: Carina Chemical Laboratories, Lower Hutt, New Zealand.
authors.forename: I J
authors.initials: IJ
authors.lastname: Miller
authors.forename: R
authors.initials: R
authors.lastname: Falshaw
authors.forename: R H
authors.initials: RH
authors.lastname: Furneaux
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D012624:Seaweed / Q000737:chemistry*
chemical_list: D011134:Polysaccharides