title: Chemical characteristics of a polysaccharide from Porphyra capensis (Rhodophyta).
abstract: The structure of a polysaccharide from the red seaweed, Porphyra capensis, growing along the coast of Namibia and South Africa was investigated. Algae growing at different sites and collected at different times gave a polysaccharide extract with similar chemical components. FTIR and NMR spectral analysis showed that the polysaccharide from P. capensis had a typical porphyran structure. It has the linear backbone of alternating 3-linked beta-D-galactose and 4-linked alpha-L-galactose-6-sulfate or 3,6-anhydro-alpha-L-galactose units. The ratio of alpha-L-galactose-6-sulfate and the 3,6-anhydrogalactose is 1.2:1, as reflected by a 1H NMR spectrum. A high degree of methylation occurred at the C-6 position of the D-galactose units. The degree of methylation was 0.64 for the D-galactose residues.
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China. qbzhang@ms.qdio.ac.cn
authors.forename: Quanbin
authors.initials: Q
authors.lastname: Zhang
authors.forename: Huimin
authors.initials: H
authors.lastname: Qi
authors.forename: Tingting
authors.initials: T
authors.lastname: Zhao
authors.forename: Eric
authors.initials: E
authors.lastname: Deslandes
authors.forename: Ninasayaeli Mbise
authors.initials: NM
authors.lastname: Ismaeli
authors.forename: F
authors.initials: F
authors.lastname: Molloy
authors.forename: Alan T
authors.initials: AT
authors.lastname: Critchley
mesh_terms: D002240:Carbohydrate Sequence; D005690:Galactose / Q000031:analogs & derivatives / Q000032:analysis; D008745:Methylation; D019906:Nuclear Magnetic Resonance, Biomolecular; D011134:Polysaccharides / Q000737:chemistry*; D044664:Porphyra / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D011134:Polysaccharides; C086947:galactose 6-sulfate; D005690:Galactose