Ulf Lindquist

Structural studies of the O-antigenic polysaccharide of Escherichia coli O86, which possesses blood-group B activity

The O-specific side-chains of the lipopolysaccharide from Escherichia coli O86:K2:H2 have been investigated using n.m.r. spectroscopy, methylation analysis, and specific degradations, and shown to be composed of the pentasaccharide repeating-unit (formula; see text) which represents the biological repeating-unit. The blood-group B activity was confirmed by an enzyme-linked immunosorbent assay.

Structural studies of the capsular polysaccharide from Streptococcus pneumoniae type 5

Abstract The structure of the capsular polysaccharide (S5) elaborated by Streptococcus pneumoniae type 5 has been investigated by using n.m.r. spectroscopy, methylation analysis, and various specific degradations. It is concluded that the polysaccharide is composed of pentasaccharide repeating-units having the following structure: In this structure, l -PneNAc stands for 2-acetamido-2,6-dideoxy- l -talose (pneumosamine) and d -Sug for 2-acetamido-2,6-dideoxy- d - xylo -hexos-4-ulose. The latter sugar accounts for the liability of S5 towards alkali. N.m.r. spectra indicate heterogeneity in S5, most probably associated with the hexosyl-4-ulose residue.

Structural studies of the capsular polysaccharide from Streptococcus pneumoniae type 4.

Abstract The structure of the capsular polysaccharide from Streptococcus pneumoniae type 4 has been investigated. Using n.m.r. spectroscopy, methylation analysis, and Smith degradation as the principal methods of structural investigation, it is concluded that the polysaccharide is composed of tetrasaccharide repeating-units having the following structure.

Structural studies of the O-antigen polysaccharide of Salmonella thompson, serogroup C1 (6,7)

The structure of the O-antigen polysaccharide of Salmonella thompson, serogroup C1 (6,7) has been investigated mainly by methylation analysis, n.m.r. spectroscopy, specific degradations by a phage-associated enzyme, N-deacetylation-deamination, and f.a.b.-m.s. It is concluded that the structure involves the following repeating unit. (formula; see text) There are two populations of chains, with and without alpha-D-glucopyranosyl groups, 3-linked to an alpha-D-Manp residue, and only the latter type is hydrolysed by the phage enzyme. The alpha linkage of the third Manp residue is cleaved by the O14 phage enzyme. The structure, with or without the alpha-D-glucopyranosyl group, represents the biological repeating-unit.

Structural Studies of an extracellular polysaccharide, S-657, elaborated by Xanthomonas ATCC 53159

Abstract The structure of an extracellular polysaccharide, S-657, elaborated by Xanthomonas ATCC 53159 was investigated by methylation analysis, specific degradations, and 1 H-n.m.r. spectroscopy. It is concluded that the polysaccharide is composed of hexasaccharide repeating-units having the structure

Structural studies of the capsular polysaccharide from streptococcus pneumoniae type 2, a reinvestigation

The structure of the capsular polysaccharide from Streptococcus pneumoniae type 2 has been reinvestigated, specific degradations and n.m.r. spectroscopy being the main methods used. It is concluded that the polysaccharide is composed of hexasaccharide repeating-units having the following structure, which differs from that previously proposed. formula; see text)

Structural studies of an extracellular polysaccharide (S-130) elaborated by Alcaligenes ATCC 31555

Abstract The structure of an extracellular polysaccharide, S-198, elaborated by Alcaligenes ATCC 31853 has been investigated; methylation analysis, specific degradations, and 1 H-n.m.r. spectroscopy were the main methods used. It is suggested that the polysaccharide is composed of “repeating units” with the structure A sugar residue in the chain may be either L -rhamnose or L -mannose and only ≈50% of the residues contain the branching α- L -rhamnopyranosyl group. The polysaccharide further contains O -acryl groups. It belongs to a group of polysaccharides, elaborated by Alcaligenes and Pseudomonas species, which all have the same linear backbone (except that some of them do not contain L -mannose) without branching or with branches that differ in their chemical structures and/or positions.

Distribution of substituents in O-(2-hydroxyethyl)cellulose

Abstract The distribution of substituents in four samples of O -(2-hydroxyethyl)cellulose has been investigated by methylation analysis. One sample was commercial and the others were prepared under conditions analogous to those used industrially during the hydroxyethylation step in the manufacture of O -ethyl- O -(2-hydroxyethyl)cellulose. The results indicate that the distribution of substituents is similar to that expected for a homogeneous reaction.

Structural studies of the capsular polysaccharide from streptococcus pneumoniae types 15b and 15c

The structures of the capsular polysaccharides (S-15B and S-15C) from Streptococcus pneumoniae types 15B and 15C have been investigated by using n.m.r. spectroscopy, methylation analysis, and various specific degradations. It is concluded that the polysaccharides are composed of pentasaccharide repeating-units having the following structure: (Formula: see text). In this structure, R is H (80%) or CH2CH2N+Me3 (20%). S-15B further contains O-acetyl groups, approximately 0.7 per repeating unit, which have not been located. The capsular polysaccharides S-15F and S-15A, which have been studied previously, are also composed of pentasaccharide repeating-units, containing the same sequence of sugars, but in a linear arrangement.

Distribution of substituents in O-ethyl-O-(2-hydroxy-ethyl)cellulose

Abstract The distribution of substituents in six O -ethyl- O -(2-hydroxyethyl)celluloses has been investigated by methylation analysis. The samples were prepared under conditions analogous to those used industrially. An analysis of the results, under simplified assumptions, indicates that the distribution of substituents in the greater part of each sample is fairly similar to that expected for a homogeneous reaction. There was, however, a considerable discrepancy between the percentage of (CH 2 CH 2 O) residues determined by analysis and the value calculated from the composition of the hydrolysate. The former value was much higher, indicating that glucose ethers with a high degree of hydroxyethylation have been overlooked in the g.l.c. analysis.