title: Structure of the O-polysaccharide of Providencia alcalifaciens O25 containing an amide of D-galacturonic acid with N(ε)-[(R)-1-carboxyethyl]-L-lysine.
abstract: An acidic O-polysaccharide was isolated by mild acid degradation of the lipopolysaccharide of Providencia alcalifaciens O25 followed by gel-permeation and anion-exchange chromatography. The O-polysaccharide was studied by sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy, including two-dimensional correlation (1)H,(13)C HMBC, and (1)H,(1)H ROESY experiments both in D(2)O and, to detect correlations for NH protons, in a 9 : 1 H(2)O/D(2)O mixture. An amino acid was isolated from the polysaccharide by acid hydrolysis and identified as N(ε)-[(R)-1-carboxyethyl]-L-lysine ("alaninolysine", 2S,8R-alaLys) by determination of the specific optical rotation and (13)C NMR spectroscopy, using the authentic synthetic diastereomers 2S,8R-alaLys and 2S,8S-alaLys for comparison. The structure of the branched tetrasaccharide repeating unit of the O-polysaccharide was established.
authors.affiliation: Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia.
authors.forename: N A
authors.initials: NA
authors.lastname: Kocharova
authors.forename: O G
authors.initials: OG
authors.lastname: Ovchinnikova
authors.forename: M
authors.initials: M
authors.lastname: Bialczak-Kokot
authors.forename: A S
authors.initials: AS
authors.lastname: Shashkov
authors.forename: Y A
authors.initials: YA
authors.lastname: Knirel
authors.forename: A
authors.initials: A
authors.lastname: Rozalski
mesh_terms: D000577:Amides / Q000737:chemistry*; D002240:Carbohydrate Sequence; D006603:Hexuronic Acids / Q000737:chemistry*; D008239:Lysine / Q000031:analogs & derivatives* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry* / Q000302:isolation & purification; D009904:Optical Rotation; D011532:Providencia / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000577:Amides; D006603:Hexuronic Acids; D019081:O Antigens; C007819:galacturonic acid; C054688:N(6)-(1-carboxyethyl)lysine; D008239:Lysine