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Disaccharide Units (disaccharide + unit)

Distribution by Scientific Domains

Chemistry	60%

Selected Abstracts

Regioselective Esterification of Various D-Glucopyranosides: Synthesis of a Fully Protected Disaccharide Unit of Hyaluronic Acid.

CHEMINFORM, Issue 48 2003
Xin-An Lu
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

An Improved Method for Synthesizing Antennary ,-D-Mannopyranosyl Disaccharide Units.

CHEMINFORM, Issue 6 2005
Ken-ichi Sato
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Metal complexes with linear and crosslinked polysaccharides as mediators of angiogenesis

POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3-4 2001
R Barbucci
Abstract Bioactive macromolecules resulting from chemical modification of hyaluronic acid (Hyal) have been designed to improve the compatibility of biomaterials used for cardiovascular prostheses. Hyal has been sulphated to obtain derivatives (HyalS) with a number of sulphate groups ranging from 1 to 4 per disaccharide unit. Hydrogels of Hyal have been obtained by cross-linking the free polysaccharide. An appropriate Hyal/cross-linking agent ratio has produced a hydrogel with a degree of crosslinking of 50%. In the present study, the ability to stimulate endothelial cell adhesion and migration was evaluated for free Hyal, HyalS3.5 and their complexes with Cu(II) and Zn(II) ions. The results revealed that Hyal and [Cu(OH)2HyalS3.5](4.5), induced cell adhesion, while [ZnHyalS3.5](2.5), and [Zn(OH)2HyalS3.5](4.5), inhibited the process. The chemotactic activity of increasing concentrations of the above complexes was also evaluated, demonstrating that [Cu(OH)2HyalS3.5](4.5), complex at 1,µM concentration was the most active in inducing cell migration. These results were also confirmed by analysing cell migration in agarose. The 50% hydrogel bound Cu(II) and Zn(II) and the in vivo biocompatibility of the complexes was found to be good. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Activation of phospholipase C pathways by a synthetic chondroitin sulfate-E tetrasaccharide promotes neurite outgrowth of dopaminergic neurons

JOURNAL OF NEUROCHEMISTRY, Issue 2 2007
Naoki Sotogaku
Abstract In dopaminergic neurons, chondroitin sulfate (CS) proteoglycans play important roles in neuronal development and regeneration. However, due to the complexity and heterogeneity of CS, the precise structure of CS with biological activity and the molecular mechanisms underlying its influence on dopaminergic neurons are poorly understood. In this study, we investigated the ability of synthetic CS oligosaccharides and natural polysaccharides to promote the neurite outgrowth of mesencephalic dopaminergic neurons and the signaling pathways activated by CS. CS-E polysaccharide, but not CS-A, -C or -D polysaccharide, facilitated the neurite outgrowth of dopaminergic neurons at CS concentrations within the physiological range. The stimulatory effect of CS-E polysaccharide on neurite outgrowth was completely abolished by its digestion into disaccharide units with chondroitinase ABC. Similarly to CS-E polysaccharide, a synthetic tetrasaccharide displaying only the CS-E sulfation motif stimulated the neurite outgrowth of dopaminergic neurons, whereas a CS-E disaccharide or unsulfated tetrasaccharide had no effect. Analysis of the molecular mechanisms revealed that the action of the CS-E tetrasaccharide was mediated through midkine-pleiotrophin/protein tyrosine phosphatase , and brain-derived neurotrophic factor/tyrosine kinase B receptor pathways, followed by activation of the two intracellular phospholipase C (PLC) signaling cascades: PLC/protein kinase C and PLC/inositol 1,4,5-triphosphate/inositol 1,4,5-triphosphate receptor signaling leading to intracellular Ca2+ concentration-dependent activation of Ca2+/calmodulin-dependent kinase II and calcineurin. These results indicate that a specific sulfation motif, in particular the CS-E tetrasaccharide unit, represents a key structural determinant for activation of midkine, pleiotrophin and brain-derived neurotrophic factor-mediated signaling, and is required for the neuritogenic activity of CS in dopaminergic neurons. [source]

Chondroitin sulphate proteoglycans in the vitreous gel of sheep and goat

BIOMEDICAL CHROMATOGRAPHY, Issue 5 2007
Spyros S. Skandalis
Abstract In the present study, the amounts and the fine structural characteristics of chondroitin sulphate proteoglycans (CSPGs) present in sheep and goat vitreous gels were determined. The results showed that in both examined species hyaluronan was the predominant glycosaminoglycan (GAG), whereas CSPGs were present in minor amounts. CSPGs were identified as versican and collagen IX with versican being the predominant PG type. Fine structural characterization indicated that the CS chains of versican in both mammalian species were of smaller size than those found in collagen IX. The difference in the sulphation pattern of CS chains between versican and collagen IX was also of particular interest. The results indicated that the predominant disaccharide type in CS side chains of versican and collagen IX from both sheep and goat vitreous gels was the 4-sulphated disaccharide. CS chains of versican were found to be richer in 4-sulphated disaccharide units than those in collagen IX, which also contained a significant proportion of non-sulphated disaccharides. These findings showed that, firstly, the CS content and the hydrodynamic size of the CS chain and, secondly, the sulphation pattern of CS chains from versican and collagen IX in both sheep and goat vitreous gels are PG type-dependent. Copyright © 2007 John Wiley & Sons, Ltd. [source]