Synthetic studies on glycosphingolipids from Protostomia phyla: syntheses and biological activities of amphoteric glycolipids containing a phosphocholine residue from the earthworm Pheretima hilgendorfi

Zwitterionic Phosphodiester-Substituted Neoglycoconjugates as Ligands for Antibodies and Acute Phase Proteins

Zwitterionic modifications of glycans, such as phosphorylcholine and phosphoethanolamine, are known from a range of prokaryotic and eukaryotic species and are recognized by mammalian antibodies and pentraxins; however, defined saccharide ligands modified with these zwitterionic moieties for high-throughput studies are lacking. In this study, we prepared and tested example mono- and disaccharides 6-substituted with either phosphorylcholine or phosphoethanolamine as bovine serum albumin neoglycoconjugates or printed in a microarray format for subsequent assessment of their binding to lectins, pentraxins, and antibodies. C-Reactive protein and anti-phosphorylcholine antibodies bound specifically to ligands with phosphorylcholine, but recognition by concanavalin A was abolished or decreased as compared with that to the corresponding nonzwitterionic compounds. Furthermore, in array format, the phosphorylcholine-modified ligands were recognized by IgG and IgM in sera of either non-infected or nematode-infected dogs and pigs. Thereby, these new compounds are defined ligands which allow the assessment of glycan-bound phosphorylcholine as a target of both the innate and adaptive immune systems in mammals.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update for 2007-2008

This review is the fifth update of the original review, published in 1999, on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2008. The first section of the review covers fundamental studies, fragmentation of carbohydrate ions, use of derivatives and new software developments for analysis of carbohydrate spectra. Among newer areas of method development are glycan arrays, MALDI imaging and the use of ion mobility spectrometry. The second section of the review discusses applications of MALDI MS to the analysis of different types of carbohydrate. Specific compound classes that are covered include carbohydrate polymers from plants, N- and O-linked glycans from glycoproteins, biopharmaceuticals, glycated proteins, glycolipids, glycosides and various other natural products. There is a short section on the use of MALDI mass spectrometry for the study of enzymes involved in glycan processing and a section on the use of MALDI MS to monitor products of the chemical synthesis of carbohydrates with emphasis on carbohydrate-protein complexes and glycodendrimers. Corresponding analyses by electrospray ionization now appear to outnumber those performed by MALDI and the amount of literature makes a comprehensive review on this technique impractical. However, most of the work relating to sample preparation and glycan synthesis is equally relevant to electrospray and, consequently, those proposing analyses by electrospray should also find material in this review of interest.

Synthesis, inhibitory effects on nitric oxide and structure-activity relationships of a glycosphingolipid from the marine sponge Aplysinella rhax and its analogues

The novel glycosphingolipid, β-D-GalNAcp(1→4)[α-D-Fucp(1→3)]-β-D-GlcNAcp(1→)Cer (A), isolated from the marine sponge Aplysinella rhax has a unique structure, with D-fucose and N-acetyl-D-galactosamine moieties attached to a reducing-end N-acetyl-D-glucosamine through an α1→3 and β1→4 linkage, respectively. We synthesized glycolipid 1 and some non-natural di- and trisaccharide analogues 2-6 containing a D-fucose residue. Among these compounds, the natural type showed the most potent nitric oxide (NO) production inhibitory activity against LPS-induced J774.1 cells. Our results indicate that both the presence of a D-Fucα1-3GlcNAc-linkage and the ceramide aglycon portion are crucial for optimal NO inhibition.

Syntheses of glycoclusters containing a phosphocholine residue related to a glycosphingolipid from the earthworm Pheretima hilgendorfi

Three types of glycoclusters related to an amphoteric glycosphingolipid found in the earthworm Pheretima hilgendorfi were synthesized. The glycoclusters were prepared from a common precursor and a simple approach for the rational design of a glycocluster was developed.

Glycosaminoglycans from earthworms (Eisenia andrei)

The whole tissue of the earthworm (Eisenia andrei) was lyophilized and extracted to purify glycosaminoglycans. Fractions, eluting from an anion-exchange column at 1.0 M and 2.0 M NaCl, showed the presence of acidic polysaccharides on agarose gel electrophoresis. Monosaccharide compositional analysis showed that galactose and glucose were most abundant monosaccharides in both fractions. Depolymerization of the polysaccharide mixture with glycosaminoglycan-degrading enzymes confirmed the presence of chondroitin sulfate/dermatan sulfate and heparan sulfate in the 2.0 M NaCl fraction. The content of GAGs (uronic acid containing polysaccharide) in the 2.0 M NaCl fraction determined by carbazole assay was 2%. Disaccharide compositional analysis using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) analysis after chondroitinase digestion (ABC and ACII), showed that the chondroitin sulfate/dermatan sulfate contained a 4-O-sulfo (76%), 2,4-di-O-sulfo (15%), 6-O-sulfo (6%), and unsulfated (4%) uronic acid linked N-acetylgalactosamine residues. LC-ESI-MS analysis of heparin lyase I/II/III digests demonstrated the presence of N-sulfo (69%), N-sulfo-6-O-sulfo (25%) and 2-O-sulfo-N-sulfo-6-O-sulfo (5%) uronic acid linked N-acetylglucosamine residues.

[Carbohydrate study for 40 years]

This review describes the carbohydrate study and the natural product related to the glycoside chemistry. What shall the people in the field of pharmacognosy and natural products chemistry search in scene in future? Forty years before while isolating dimeric compound having naphthoquinonepyrone skeleton from the coloring material produced by the pathogen that hosted in wheat and caused rotten root disease, silica gel has to be treated with oxalic acid to reduce the absorbency before separation. However now a days, availability of reversed phase adsorbents for liquid chromatography has made the separation and isolation of complex compounds possible, easy and rapid. With the advancement of mechanical/physicochemical analytic methods, it has even been possible to isolate traces of compounds present in complex. This advancement has made it possible to determine structure of saponins and complex polysaccharides without decomposition and carry out in vitro bioassay at the same time using various cells on-line. Further, this review describes the oligosaccharide syntheses and biological activities of glycosphingolipids, focusing especially on those found in invertebrates.