257614-58-7Relevant academic research and scientific papers
4,6- O-Pyruvyl Ketal Modified N-Acetylmannosamine of the Secondary Cell Wall Polysaccharide of Bacillus anthracis Is the Anchoring Residue for Its Surface Layer Proteins
Chapman, Robert N.,Liu, Lin,Boons, Geert-Jan
supporting information, p. 17079 - 17085 (2018/12/14)
The secondary cell wall polysaccharide (SCWP) of Bacillus anthracis plays a key role in the organization of the cell envelope of vegetative cells and is intimately involved in host-guest interactions. Genetic studies have indicated that it anchors S-layer and S-layer-associated proteins, which are involved in multiple vital biological functions, to the cell surface of B. anthracis. Phenotypic observations indicate that specific functional groups of the terminal unit of SCWP, including 4,6-O-pyruvyl ketal and acetyl esters, are important for binding of these proteins. These observations are based on genetic manipulations and have not been corroborated by direct binding studies. To address this issue, a synthetic strategy was developed that could provide a range of pyruvylated oligosaccharides derived from B. anthracis SCWP bearing base-labile acetyl esters and free amino groups. The resulting oligosaccharides were used in binding studies with a panel of S-layer and S-layer-associated proteins, which identified structural features of SCWP important for binding. A single pyruvylated ManNAc monosaccharide exhibited strong binding to all proteins, making it a promising structure for S-layer protein manipulation. The acetyl esters and free amine of SCWP did not significantly impact binding, and this observation is contrary to a proposed model in which SCWP acetylation is a prerequisite for association of some but not all S-layer and S-layer-associated proteins.
Synthesis, biological evaluation and structure-activity relationship studies of hederacolchiside E and its derivatives as potential anti-Alzheimer agents
Li, Hui-ning,Liu, Yang,Zhang, Zuo-peng,Wang, Zhi-peng,Hao, Jing-zheng,Li, Feng-ran,Fan, Zhan-fang,Zou, Li-bo,Cheng, Mao-sheng
supporting information, p. 376 - 389 (2017/12/07)
Inspired by the previously reported neuroprotective activity of hederacolchiside E (1), we synthesized hederacolchiside E for the first time along with eleven of its derivatives. The neuroprotective effects of these compounds were further evaluated agains
First Total Synthesis of Ganglioside GAA-7 from Starfish Asterias amurensis versicolor
Tamai, Hideki,Imamura, Akihiro,Ogawa, Junya,Ando, Hiromune,Ishida, Hideharu,Kiso, Makoto
, p. 5199 - 5211 (2015/08/18)
The first total synthesis of neuritogenic ganglioside GAA-7 was achieved using the glucosyl ceramide (Glc-Cer) cassette approach. The stereocenter triad within the ceramide moiety of the target molecule was efficiently established from D-lyxose. The assem
Sonochemistry: A powerful way of enhancing the efficiency of carbohydrate synthesis
Deng, Shenglou,Gangadharmath, Umesh,Chang, Cheng-Wei Tom
, p. 5179 - 5185 (2007/10/03)
Using sonication as a means of facilitating organic reactions in carbohydrate chemistry was explored under the conditions used for traditional organic synthesis. An array of representative reactions, including hydroxy group manipulation (acylation, protection/deprotection, acyl group migration), thioglycoside synthesis, azidoglycoside synthesis, 1,3-dipolar cycloaddition and reductive cleavage of benzylidene, commonly used in the synthesis of carbohydrate derivatives was examined. A series of glycosylation reactions that employ thioglycosides, glycosyl trichloroacetimidate, glycosyl bromide and glycosyl acetate as the glycosyl donors was also examined. Our results demonstrate that sonication can significantly shorten the reaction time, enhance the reactivity of reactant and lead to superior yield and excellent stereoselectivity. More importantly, a general protocol of glycosylation may finally be developed. Sonication is compatible to the conditions used for traditional organic synthesis. We believe that sonication can also be applied to other areas of synthetic processes.
