Entity

Time filter

Source Type

Saint-Malo, France

Vetvicka V.,University of Louisville | Saraswat-Ohri S.,University of Louisville | Vashishta A.,University of Louisville | Descroix K.,National Graduate School of Chemistry, Rennes | And 5 more authors.
Carbohydrate Research | Year: 2011

(1→3)-β-d-Glucans are well-established natural biological immunomodulators. However, problems inherited with the natural origin of these polysaccharides bring about significant setbacks, including batch-to-batch heterogeneity and significant differences based on the source and isolation techniques. In this study, we tried to overcome these problems by preparation of a quantitatively new set of oligo-(1→3)-β-d-glucan-based synthetic immunomodulators. Some of these non-natural oligosaccharides showed biological activities, such as stimulation of phagocytosis, modulation of gene expression, and anti-cancer activity, which were superior to natural glucans. © 2011 Elsevier Ltd. All rights reserved. Source


Saraswat-Ohri S.,University of Louisville | Vashishta A.,University of Louisville | Vetvicka V.,University of Louisville | Descroix K.,National Graduate School of Chemistry, Rennes | And 5 more authors.
Journal of Medicinal Food | Year: 2011

Despite the fact that β-glucans are well-established immunomodulators, the problems with batch-to-batch heterogeneity remains problematic. The aim of this study was to prepare and evaluate new type of synthetic oligosaccharides. A new family of oligo-(1→3)-β-d-glucans modified on the reducing end was synthesized using a controlled and specific inversion of configuration at C-2 starting from already formed oligo-(1→3)-β-d-glucans. The designed glycosides are characterized by the presence of four or five glucopyranose entities and a mannose residue at the reducing end. To study of the impact of well-defined structural modulations, we used murine and human models to evaluate their immunostimulating potential. These novel oligosaccharides showed strong and long-lasting stimulation of phagocytosis and significant potentiation of synthesis and/or secretion of interleukin (IL-2, IL-4, IL-5, IL-6), tumor necrosis factor-α, and vascular endothelial growth factor. In addition, the oligosaccharides tested showed significant effects on expression of several genes in human fibroblasts and breast cancer cells. From our results it is clear that these synthetic oligosaccharides represent a better alternative to natural β-glucans. © Copyright 2011, Mary Ann Liebert, Inc. and Korean Society of Food Science and Nutrition. Source


Descroix K.,National Graduate School of Chemistry, Rennes | Descroix K.,European University of Brittany | Vetvicka V.,University of Louisville | Laurent I.,National Graduate School of Chemistry, Rennes | And 5 more authors.
Bioorganic and Medicinal Chemistry | Year: 2010

Oligo-β-(1,3)-glucans were chemically modified in order to introduce a structural variation specifically on the reducing end of the oligomers. The impact of well defined structural modulations was further studied on cancer cells and murin models to evaluate their cytotoxicity and immunostimulating potential. © 2009 Elsevier Ltd. Source


Sylla B.,National Graduate School of Chemistry, Rennes | Sylla B.,European University of Brittany | Descroix K.,National Graduate School of Chemistry, Rennes | Descroix K.,European University of Brittany | And 15 more authors.
Carbohydrate Research | Year: 2010

It is known that 3-O-glycosylation of glucosidic acceptors bearing acyl groups in the 4 and 6 positions instead of a 4,6-O-benzylidene ring mainly affords α-glycosides. Described here is an unexpected stereochemical outcome for elongation at glucose O-3 of a β-D-Glcp-(1→3)-α-D- Manp disaccharide using peracetylated ethyl thioglucoside as a donor. This unexpected reaction was correlated with match-mismatch effects, as shown by efficient coupling of the same acceptor by a donor of L-configuration. © 2010 Elsevier Ltd. All rights reserved. Source

Discover hidden collaborations