1-Benzenesulfonyl- and 1-p-toluenesulfonyl-3-methylimidazolium triflates: efficient reagents for the preparation of arylsulfonamides and arylsulfonates
Fluorosugar Chain Termination Agents as Probes of the Sequence Specificity of a Carbohydrate Polymerase
作者:Christopher D. Brown、Max S. Rusek、Laura L. Kiessling
DOI:10.1021/ja301723p
日期:2012.4.18
Naturally occurring carbohydrate polymers are ubiquitous. They are assembled by polymerizing glycosyltransferases, which can generate polysaccharide products with repeating sequence patterns. The fidelity of enzymes of this class is unknown. We report a method for testing the fidelity of carbohydrate polymerase pattern deposition: we synthesized fluorosugar donors and used them as chain termination agents. The requisite nucleotide fluorosugars could be produced from a single intermediate using the Jacobsen catalyst in a kinetically controlled separation of diastereomers. The resulting fluorosugar donors were used by the galactofuranosyltransferase GlfT2 from Mycobacterium tuberculosis, and the data indicate that this enzyme mediates the cell wall galactan production through a sequence-specific polymerization.
Sulfonyl Imidazolium Salts as Reagents for the Rapid and Efficient Synthesis of Nucleoside Polyphosphates and Their Conjugates
作者:Samy Mohamady、Ahmed Desoky、Scott D. Taylor
DOI:10.1021/ol203178k
日期:2012.1.6
A procedure for the synthesis of nucleosidepolyphosphates and their conjugates using sulfonylimidazolium salts as key reagents is described. The procedure is rapid and high yielding, does not require prior protection and subsequent deprotection of the donors or acceptors, and can be used to activate nucleoside mono-, di- and triphosphates, and a wide variety of acceptors and donors can be used.
1-Benzenesulfonyl- and 1-p-toluenesulfonyl-3-methylimidazolium triflates: efficient reagents for the preparation of arylsulfonamides and arylsulfonates