Syntheses of New Model Compounds Related to an Antigenic Epitope from Bupleurum falcatum L. and Their Distributions in Various Ganglioside-Phospholipid Monolayers

[Elucidation of carbohydrate functions in cell membranes--development of molecular tool containing carbohydrate ligand and elucidation of interface phenomena of glycolipid]

Glycosphingolids and glycoproteins in cell membrane are thought to play important roles in variety biological phenomena. Our interests focused on elucidation of their functions at the molecular level. We are especially interested in organic chemistry and physical chemistry of carbohydrates. Physical part-Surface of Langmuir-Blodgett (LB) films which comprised of various gangliosides, sphingolipids and cholesterol are observed by atomic force microscopy (AFM). We studied distribution of model compounds related to an antigenic epitope from Bupleurum falcatum L. in G(M3) (GM3)-DPPC monolayers. We also investigated relation between disease and glycolids in cell membrane. Chemical part-New molecular tools for the elucidation of carbohydrate roles using photoaffinity labeling were developed. We showed that the structural difference between closed ring- and open ring-type carbohydrates affected binding affinity to proteins. This study confirmed that carbohydrate structure, in both non-reducing end and reducing end sugars, is deeply related to the recognition event between carbohydrates and proteins. As a result, they will be used in future studies to elucidate carbohydrate functions on cell surfaces.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: an update for the period 2005-2006

This review is the fourth 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 2006. The review covers fundamental studies, fragmentation of carbohydrate ions, method developments, and applications of the technique 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, glycated proteins, glycolipids from bacteria, glycosides, and various other natural products. There is a short section on the use of MALDI-TOF mass spectrometry for the study of enzymes involved in glycan processing, a section on industrial processes, particularly the development of biopharmaceuticals and a section on the use of MALDI-MS to monitor products of chemical synthesis of carbohydrates. Large carbohydrate-protein complexes and glycodendrimers are highlighted in this final section.

[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.

Syntheses and Biological Activities of Glycoconjugates

This review describes the oligosaccharide syntheses and biological activities of glycosphingolipids, focusing especially on those found in invertebrates like millipedes, nematoda parasites, and cestoda parasites, and model compounds related to a major antigenic epitope against antibupleurum 2IIc/PG-1-IgG from antiulcer pectic polysaccharides. A novel and simple approach for the rational design of glycoclusters and glycodendrimers by coupling with a sugar unit and a cluster unit, was developed with beta-alanine derivatives used to construct the latter compounds.