title: Structural characterisation of galactoglucomannan secreted by suspension-cultured cells of Nicotiana plumbaginifolia.
abstract: Galactoglucomannan (GGM) from cultures of Nicotiana plumbaginifolia has Man:Glc:Gal:Ara:Xyl in 1.0:1.1:1.0:0.1:0.04 ratio. Linkage analysis contained 4- and 4,6-Manp, 4-Glcp, terminal Galp and 2-Galp, small amounts and terminal Arap and terminal Xylp, and approximately 0.03 mol acetyl per mol of glucosyl residue. Treatment with alpha- and beta-D-galactosidases showed that the majority of the side-chains were either single Galp-alpha-(1-->residues or the disaccharide Galp-beta-(1-->2)-Galp-alpha-(1-->linked to O-6 of the 4-Manp residues of the glucomannan backbone. Analysis of the oligosaccharides generated by endo-(1-->4)-beta-mannanase digestion confirmed that the GGM comprises a backbone of predominantly alternating-->4)-D-Manp-beta-(1-->and-->4)-D-Glcp-beta-(1-->branch ed at O-6 of 65% of the 4-Manp residues. The major oligosaccharide identified was D-Glcp-beta-(1-->4)-[D-Galp-beta-(1-->2)-D-Galp-alpha-(1-->6)]-D-Man p-beta-(1-->4)-D-Glcp-beta-(1-->4)-[D-Galp-alpha-(1-->6)]-D-Manp -beta-(1-->(27%), and most of the other oligosaccharides produced in significant quantities were based on this structure.
authors.affiliation: Cooperative Research Centre for Industrial Plant Biopolymers, School of Botany, University of Melbourne, Victoria, Australia.
authors.forename: I M
authors.initials: IM
authors.lastname: Sims
authors.forename: D J
authors.initials: DJ
authors.lastname: Craik
authors.forename: A
authors.initials: A
authors.lastname: Bacic
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000378:metabolism; D010947:Plants, Toxic; D014026:Nicotiana / Q000166:cytology / Q000502:physiology*
chemical_list: D009844:Oligosaccharides; C065125:Galp-GlcpNac-Manp-(GlcpNAc)-(Galp-GlpNAc-Manp)-Manp-GlcNac