Four major saponins from Solidago canadensis.

Four new bisdesmosidic saponins each containing eight carbohydrate units were isolated from Solidago canadensis. GC, GC-MS, FABMS analysis and mainly the use of 2D NMR techniques allowed their identification as bayogeninglycosides (canadensissaponins 1-4) 3-O- [beta-D-glucopyranosyl-(1----3)-beta-D-glucopyranosyl]-28-O-[alpha-L- rhamnopyranosyl-(1----3)-beta-D-xylopyranosyl-(1----4)-[beta-D- xylopyranosyl-(1----3)]-alpha-L-rhamnopyranosyl-(1----2)-[beta-D- apio-D-furanosyl-(1----3)]-beta-D-6-deoxyglucopyranosyl- (1----]-bayogenin; -(1----2)-[beta-D-apio-D-furanosyl-(1----3)]-ara- binopyranosyl-(1----]-bayogenin; -[alpha-L-rhamnopyranosyl-(1----3)]-beta- D-6-deoxyglucopyranosyl-(1----]-bayogenin and - [alpha-L-rhamnopyranosyl- (1----3)]-arabinopyranosyl-(1----]-bayogenin.     

Isolation and structure determination of a diacetamidodideoxyuronic acid-containing glycan chain from the S-layer glycoprotein of Bacillus stearothermophilus NRS 2004/3a

A glycan isolated from the surface-layer glycoprotein of Bacillus stearothermophilus strain NRS 2004/3a was shown by 1H- and 13C-n.m.r. spectroscopy to have the tetrasaccharide repeating-unit ----4)-beta-ManpA2,3(NAc)2-(1----3)-alpha-GlcpNAc-(1----4)-beta- ManpA2,3(NAc)-(1----6)-alpha-Glcp(1----.     

Enzymic synthesis of oligosaccharides terminating in the tumor-associated sialyl-Lewis-a determinant

The isomeric sialyl-Lea-terminating pentasaccharide derivatives, alpha-Neup5Ac-(2----3)-beta-D-Galp-(1----3)-[alpha-L-Fucp-(1 ----4)]-beta- D-GlcpNAc-(1----3)-beta-D-Galp-O(CH2)8COOMe and alpha-Neup5Ac-(2----3)-beta-D-Galp-(1----3)-[alpha-L-Fucp-(1 ----4)]- beta-D-GlcpNAc-(1----6)-beta-D-Galp-O(CH2)8COOMe, have been prepared by the action in sequence of a porcine submaxillary (2----3)-alpha-sialyltransferase and a human-milk (1----3/4)-alpha-fucosyltransferase on the chemically synthesized trisaccharides beta-D-Galp-(1----3)-beta-D-GlcpNAc-(1----3)- and -(1----6)-beta-D-Galp- O(CH2)8COOMe, respectively.     

Biologically active labdane-type diterpene glycosides from the root-stalks of Gleichenia japonica.

A glycoside showing a strong growth inhibition of lettuce was isolated from the root-stalks of Gleichenia japonica and its structure was established to be the 3-O-alpha-rhamnopyranosyl-(1----2)-beta-glucopyranoside of 13-O-alpha-rhamnopyranosyl-(+)-3 beta-hydroxymanool. In addition, two related glycosides were also isolated and they were characterized as the 3-O-beta-fucopyranosyl-(1----3)-alpha-rhamnopyranosyl-(1----2)-beta- glucopyranoside of 13-O-alpha-rhamnopyranosyl-(+)-3 beta-hydroxymanool and the 13-O-rhamnopyranoside of the same diterpene alcohol. The diterpene alcohol accelerated the growth of lettuce.     

Steroidal saponins from the bulbs of Camassia cusickii.

Six new steroidal saponins have been isolated from the fresh bulbs of Camassia cusickii. Their structures were determined by spectroscopic analysis and some chemical transformations to be (25R)-5 alpha-spirostan-3 beta,6 alpha-diol (chlorogenin) 6-O-beta-D-glucopyranoside, chlorogenin 6-O-beta-D-glucopyranosyl-(1----2)-beta-D-glucopyranoside, chlorogenin 6-O-beta-D-glucopyranosyl-(1----3)-beta-D-glucopyranoside, chlorogenin 6-O-beta-D-glucopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----3)]-beta- D-glucopyranoside, (25R)-6 alpha-hydroxy-5 alpha-spirostan-3-one 6-O-beta-D-glucopyranosyl- (1----3)-beta-D-glucopyranoside and (25R)-3,3-dimethoxy-5 alpha-spirostan-6 alpha-ol 6-O-beta-D-glucopyranosyl-(1----3)-beta-D-glucopyranoside. The saponins isolated were shown to contribute to the bitter taste of the bulbs.     

Antigenic polysaccharides of bacteria. 17. The structure of O-specific polysaccharide chain of Pseudomonas aeruginosa X (Meitert) lipopolysaccharide

O-Specific polysaccharide composed of L-rhamnose and 2-acetamido-2-deoxy-D-mannose was obtained on mild acid degradation of P. aeruginosa X (Meitert classification) lipopolysaccharide. On the basis of non-destructive analis using 1H, 13C NMR spectroscopy and Klyne's rule calculation, as well as chemical methods (acid hydrolysis, methylation, Smith degradation), it was established that the polysaccharide is built up of disaccharide repeating units of the following structure: ----4)-alpha-L-Rha-(1----3)-beta-D-ManNAc-(1----.     

Biosynthesis of disialylated beta-D-galactopyranosyl-(1----3)-2-acetamido-2-deoxy-beta-D-glucopy ran osyl oligosaccharide chains. Identification of a beta-D-galactoside alpha-(2----3)- and a 2-acetamido-2-deoxy-beta-D-glucoside alpha-(2----6)-sialyltransferase in regenerating rat liver and other tissues

Regenerating rat liver microsomes contain a beta-D-galactoside alpha-(2----3)- and a 2-acetamido-2-deoxy-beta-D-glucoside alpha-(2----6)-sialyltransferase that are involved in the synthesis of the terminal alpha-NeuAc-(2----3)-beta-D-Galp-(1----3)-alpha-[NeuAc-(2----6)]-beta- D-GlcpNAc-(1----R) group occurring in human milk oligosaccharides and the glycan chains of several N-glycoproteins. Analysis by liquid chromatography and methylation of the products of sialylation obtained when lacto-N-tetraose [beta-D-Galp-(1----3)-beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4) -D-Glc] was used as a substrate in the incubations in vitro indicated that the disialylated sequence is formed for greater than 95% through the tetrasaccharide alpha-NeuAc-(2----3)-beta-D-Gal-(1----3)-beta-D-GlcNAc-(1----3)-beta-D-G al- (1----4)-D-Glc as one of two possible intermediates. This indicates that in the synthesis of the disialylated sequence the alpha-(2----3)- and the alpha-(2----6)-sialyltransferase act in a highly preferred order in which the alpha-(2----3) enzyme acts first. This order is imposed by the specificity of the alpha-(2----6)-sialyltransferase, which requires an alpha-NeuAc-(2----3)-beta-D-Gal-(1----3)-beta-D-GlcNAc-(1----R) sequence for optimal activity, and shows very low and no activity with beta-D-Gal-(1----3)-beta-D-GlcNAc-(1----R) and beta-D-GlcNAc-(1----R) acceptor structures, respectively. Results obtained with normal rat, fetal calf, rabbit and human liver, and human placenta indicated that very similar or identical sialyltransferases occur in these tissues. It is suggested that these enzymes differ from the sialyltransferases that previously had been identified in fetal calf liver and human placenta.     

Antigenic bacterial polysaccharides. 23. The structure of the O-specific polysaccharide chain of Salmonella arizonae 059 lipopolysaccharide

The O-specific polysaccharide of Salmonella arizonae O59 (Arizona 19) is composed of D-galactose, N-acetyl-D-glucosamine, and N-acetyl-L-fucosamine (FucNAc, 2-acetamido-2,6-dideoxy-L-galactose) in the ratio 1:1:1. The computerized calculation of the 13C NMR spectrum of the polysaccharide, based on the monosaccharide composition, spectra of the free monosaccharides and glycosydation effects, together with the chemical analysis (methylation and Smith degradation) showed that the polysaccharide is built up of trisaccharide repeating units of the following structure: ----3)-alpha-L-FucNAcp(1----3)-beta-D-GlcNAcp-(1----2)-beta- D-Galp-1(----. The molecular basis of serological interrelations between S. arizonae O59 and Pseudomonas aeruginosa O7 (Lányi) is discussed.     

Structure of an exocellular polysaccharide produced by Streptococcus thermophilus

Streptococcus thermophilus strains grown on skimmed milk produced a viscosifying, exocellular, and water-soluble polysaccharide which contains D-glucose, D-galactose, and N-acetyl-D-galactosamine in the ratio of 1:2:1. Methylation analysis identified the glycosidic linkages in the tetrasaccharidic repeating-unit, and Smith degradation and nitrous deamination after N-deacetylation gave the sequence of monosaccharides in the repeating-unit. The anomeric configurations of the sugar residues were determined by oxidation of the peracetylated polysaccharide with chromium trioxide and by 1H- and 13C-n.m.r. spectroscopy. The following structure was assigned to the repeating unit of the polysaccharide,----3)-beta-D-Galp-(1----3)-[alpha-D-Galp-(1----6)]-beta- D- Glcp-(1----3)-alpha-D-GalpNAc-(1----.     

Isolation and structure of glucan from regenerating spheroplasts of Candida albicans

Regenerating spheroplasts of Candida albicans formed organized glucan nets in liquid culture. The nets consisted of interwoven microfibrils about 50 nm wide, but of an undetermined length. Partial acid hydrolysis of the polysaccharide showed the presence of chains of beta(1----3)- and beta(1----6)-linked glucose residues, but no intrachain beta(1----3) and beta(1----6) linkages. Periodate oxidation and GLC of the methylated glucan indicated a highly branched polymer (9.5% branch points). Sequential enzymic degradation of the isolated nets confirmed the presence of chains of beta(1----3)- and beta(1----6)-linked glucose residues. Degradation by (1----3)-beta- and (1----6)-beta-glucanase released 23% (w/w) and 30% (w/w) respectively of the carbohydrate as glucose equivalents. The residual material was degraded by chitinase. Equal amounts of N-acetylglucosamine and glucose equivalents were detected in the chitinase hydrolysate, suggesting a possible linkage between glucan and chitin. Our data indicate that the cell wall of C. albicans contains at least two highly branched glucans with predominantly beta(1----3) or beta(1----6) linkages.     

Elongation of both branches of biantennary backbones of oligo-(N-acetyllactosamino)glycans by human serum (1----3)-N-acetyl-beta-D- glucosaminyltransferase.

Partial reactions catalyzed by a (1----3)-N-acetyl-beta-D- glucosaminyltransferase (EC2.4.1.149), known to be present in human serum, were studied by use of biantennary "backbone" saccharides of oligo-N-acetyllactosamine-type as acceptors. Incubation of the radiolabeled blood-group I-active hexasaccharide, beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-[beta-D-Galp- (1----4)-beta-D-GlcpNAc-(1----6)]-beta-D-Galp-(1----4)-D-GlcNAc (1) and UDP-GlcNAc with serum gave first a transient 1:1 mixture of two isomeric heptasaccharides, beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-beta-D- GlcpNAc-(1----3)-[beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----6)]-beta-D- Galp-(1----4)-D-GlcNAc (2) and beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-[beta-D-GlcpNAc-(1----3)- beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----6)]-beta-D-Galp-(1----4)-D-Glc NAc (3), showing that both branches of 1 react equally well. The two heptasaccharides reacted further in the incubation mixture to form the radiolabeled octasaccharide, beta-D-GlcpNAc-(1----3)-beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-[be ta-D- GlcpNAc-(1----3)-beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----6)]-beta-D-Ga lp- (1----4)-D-GlcNAc (4); during this second reaction, the composition of the heptasaccharide mixture remained unchanged, indicating that 2 and 3 reacted at approximately equal rates. The heptasaccharides 2 and 3 could not be separated from each other, but they could be detected, identified, and quantitatively determined by stepwise enzymic degradations. Partial (1----3)-N-acetyl-beta-D-glucosaminylation reactions, carried out with another acceptor, the branched pentasaccharide, beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----3)-[beta-D-Galp-(1----4)-beta- D- GlcpNAc-(1----6)]-beta-D-Gal (11), revealed that it reacted also equally well at both branches.(ABSTRACT TRUNCATED AT 400 WORDS)     

Initiation of poly-N-acetyllactosamine chain biosynthesis occurs preferentially on complex multiantennary asparagine-linked oligosaccharides

An N-acetyl-beta-D-glucosaminyltransferase activity involved in the initiation of poly-N-acetyllactosamine chain biosynthesis can be solubilized from Ehrlich ascites tumor cell microsomal membranes. The ability of this enzyme to act on linear and branched acceptor substrates has been studied. The results indicate that complex-type tri- and tetra-antennary oligosaccharides exhibiting the branching pattern beta-D-Galp-(1----4)-beta-D-GlcpNAc-(1----6)-[beta-D-Galp-(1----4)-beta- D- Glcp-NAc-(1----2)]-D-Man are the preferred substrates for the enzyme, and therefore, may represent the structures upon which the generation of poly-N-acetyllactosamine chains proceeds more efficiently.     

The occurrence of glucosaminoglycan in the wall of Schizosaccharomyces pombe

The major part of the wall of Schizosaccharomyces pombe consists of (1----3)-alpha-glucan and (1----3)-beta-glucan with some (1----6)-beta-linkages. Although in hydrolysed samples only a minute amount of glucosamine could be detected, this amino sugar may play an essential role as an integral part of a glucosaminoglycan/glucan complex. Treatment of the wall with either nitrous acid or chitinase changed the solubility properties of the beta-glucan, which suggests that the glucosaminoglycan/glucan complex is essentially similar to that found in walls of other fungi. An enzyme with properties similar to that of chitin synthase of other fungi, and probably responsible for the synthesis of the glucosaminoglycan, was detected in a mixed-membrane fraction.     

Scammonins I and II, the resin glycosides of radix scammoniae from Convolvulus scammonia.

The ether-soluble resin glycoside ('jalapin') fraction obtained from scammony roots, on alkaline hydrolysis, gave a glycosidic acid, scammonic acid A, together with isobutyric, 2S-methylbutyric and tiglic acids. In addition, two kinds of resin glycosides, named scammonin I and II, were isolated and characterized, respectively, as (11S)-hydroxyhexadecanoic acid, 11-[( O-6-deoxy-4-O-(2(E)-methyl-1-oxo-2- butenyl)-beta-D-glucopyranosyl-(1----4)-O-6-deoxy-2-O-(2-methyl-1-oxobut yl)- alpha-L-mannopyranosyl-(1----2)-O-beta-D-glucopyranosyl-(1----2)-6-deoxy -beta- D-glucopyranosyl]oxy)-, intramol. 1,3"'-ester and (11S)-hydroxyhexadecanoic acid, 11-[( O-beta-D-glucopyranosyl-(1----4)-O-6-deoxy-2-O-(2-methyl-1-oxobutyl)- alpha-L-mannopyranosyl-(1----2)-O-beta-D-glucopyranosyl-(1----2)-6-deoxy -beta-D - glucopyranosyl]oxy)-, intramol. 1,3"'-ester.     

Asparagine-linked sugar chains of fetuin: occurrence of tetrasialyl triantennary sugar chains containing the Gal beta 1----3GlcNAc sequence

Asparagine-linked sugar chains were quantitatively released from fetuin by hydrazinolysis. Structural analysis of the sugar chains by sequential exoglycosidase digestion in combination with methylation analysis and Smith degradation revealed that most of them have typical biantennary (8%) and triantennary (74%) structures containing different amounts of N-acetylneuraminic acid residues. In addition, an unusual tetrasialyl triantennary sugar chain (17%) containing the Gal beta 1----3GlcNAc sequence in the outer chain moiety was detected, and its structure was elucidated as NeuAc alpha 2----3Gal beta 1----3(NeuAc alpha 2----6)-GlcNAc beta 1----4(NeuAc alpha 2----6Gal beta 1----4GlcNAc beta 1----2)Man alpha 1----3(NeuAc alpha 2----3Gal beta 1----4GlcNAc beta 1----2Man alpha 1----6)Man beta 1----4GlcNAc beta 1----4GlcNAc.     

Synthesis, structure, and conformation of the dilactone derivative of GD1b ganglioside

Treatment of DG1b, beta-Gal-(1----3)-beta-GalNAc-(1---- 4)-[alpha-Neu5Ac-(2----8)-alpha-Neu5Ac-(2---- 3)]-beta-Gal-(1----4)-beta-Glc-(1----1)-Cer, with dicyclohexylcarbodi-imide in anhydrous methyl sulfoxide affords 95-98% of GD1b-dilactone. The carboxyl groups of the two sialic acid units are involved in ester linkages, as proved by ammoniolysis and reduction which gave derivatives containing the amide of sialic acid and N-acetylneuraminulose, respectively. 1H-N.m.r. spectroscopy showed that the lactone rings involved position 9 of the inner sialic acid and position 2 of the inner galactose and that the disialosyl chain is extended toward the -beta-Gal-(1 ----4)-beta-Glc- portion of the ganglioside moiety.     

Structure of a triphosphonopentaosylceramide containing 4-O-methyl-N-acetylglucosamine from the skin of the sea hare, Aplysia kurodai

A novel phosphonoglycosphingolipid named SGL-I containing 3 mol of 2-aminoethylphosphonate residues was isolated from the skin of a sea gastropod, Aplysia kurodai. The saccharide moiety of the glycolipid was characterized as 4-O-methyl-GlcNAc alpha 1----4GalNAc alpha-1----3 [6'-O-(2-aminoethylphosphonyl)Gal alpha 1----2] (2-aminoethylphosphonyl----6)Gal beta 1----4(2-aminoethylphosphonyl----6) Glc beta 1----1-ceramide. The major aliphatic components of the ceramide portion were palmitic acid, stearic acid, octadeca-4-sphingenine, and anteisononadeca-4-sphingenine. This glycolipid is unique in containing 4-O-methyl-N-acetylglucosamine and 3 mol of 2-aminoethylphosphonate residues, one of which is attached to C-6 of glucose.     

The structures of N- and O-glycosidic carbohydrate chains of a chondroitin sulfate proteoglycan isolated from the media of the human aorta

A large Mr chondroitin sulfate proteoglycan was extracted from the media of human aorta under dissociative conditions and purified by density-gradient centrifugation, ion-exchange chromatography, and gel filtration chromatography. Removal of a contaminating dermatan sulfate proteoglycan was accomplished by reduction, alkylation and rechromatography on the gel filtration column. After chondroitinase ABC treatment, the proteoglycan core was separated from a residual heparan sulfate proteoglycan by a third gel filtration chromatography step. As assessed by radioimmunoassay, the isolated proteoglycan core was free of link protein, but possessed epitopes that were recognized by antisera against the hyaluronic acid binding region of bovine cartilage proteoglycan as well as those that were weakly recognized by anti-keratan sulfate antisera. Following beta-elimination of the protein core, the liberated low Mr oligosaccharides were partially resolved by Sephadex G-50 chromatography, and their primary structure was determined by 500-MHz1H NMR spectroscopy in combination with compositional sugar analysis. The N-glycosidic carbohydrate chains, which were obtained as glycopeptides, were all biantennary glycans containing NeuAc and Fuc; microheterogeneity in the NeuAc----Gal linkage was detected in one of the branches. The N-glycosidic glycans have the following overall structure: (Formula: see text). The majority of the O-glycosidic carbohydrate chains bound to the protein core were found to be of the mucin type. They were obtained as glycopeptides and oligosaccharide alditols, and possessed the following structures: NeuAc alpha(2----3)Gal beta(1----3)GalNAc-ol, [NeuAc alpha(2----3)Gal beta(1----3)[NeuAc alpha(2----6)]GalNAc-ol, and NeuAc alpha-(2----3) Gal beta(1----3)[NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)] GalNAc-ol. The remainder of the O-glycosidic carbohydrate chains bound to the isolated proteoglycan were the hexasaccharide link regions of the chondroitin sulfate chains that remained after chondroitinase ABC treatment of the native molecule. These latter glycans, which were obtained as oligosaccharide alditols, had the following structure (with GalNAc free of sulfate or containing sulfate bound at either C-4 or C-6): delta 4,5GlcUA beta(1----3)GalNAc beta(1----4)GlcUA beta(1----3)Gal beta(1----3)Gal beta(1----4)Xyl-ol.     

Novel phosphonoglycosphingolipids containing pyruvylated galactose from the nervous system of Aplysia kurodai

We have reported the existence of a phosphonoglycosphingolipid containing a pyruvylated galactose, FGL-IIb, in nerve fibers of Aplysia kurodai (Araki, S., Abe, S., Ando, S., Kon, K., Fujiwara, N. & Satake, M. (1989) J. Biol. Chem. 264, 19922-19927). We have now isolated two other pyruvylated galactose-containing phosphonoglycosphingolipids, named FGL-V and FGL-IIa, from the nervous tissue of Aplysia, and characterized them as [3,4-O-(S-1-carboxyethylidene)]Gal beta 1----3GalNAc alpha 1----3[6'-O-(2- aminoethylphosphonyl)Gal alpha 1----2] (2-aminoethylphosphonyl----6) Gal beta 1----4Glc beta 1----1 ceramide and [3,4,O-(S-1-carboxyethylidene)] Gal beta 1----3GalNAc alpha 1----3[6'-O-(2-aminoethylphosphonyl)Gal alpha 1----2]Gal beta 1----4Glc beta 11----ceramide, respectively. Their major aliphatic components are palmitic acid, octadeca-4-sphingenine and anteisononadeca-4-sphingenine. Thus, the nervous system of Aplysia contains several pyruvylated phosphonoglycolipids.     

Purification, characterization and immunological properties of the serotype-specific capsular polysaccharide of Pasteurella haemolytica serotype A7 organisms

The serotype-specific capsular polysaccharide from two strains of Pasteurella haemolytica serotype A7 organisms was purified and characterized by chemical analysis and by 1H and 13C NMR spectroscopy using one- and two-dimensional methods. The polymer has the repeating unit----3)-beta-2-acetamido-2-deoxygalactopyranose-(1----3)-alpha- 2-acetamido- 2-deoxy-6-O-acetyl-glucopyranose-(1-phosphate----. It was immunogenic (capable of eliciting antibodies) for sheep. Chemical removal of O-acetyl groups destroyed both the ability of the polymer to adhere to sheep erythrocytes at neutral pH and the ability to form immune precipitates with specific antisera. Studies using the protein A-gold technique in the electron microscope showed the polysaccharide to be peripherally localized on the bacterial surface.