136025-58-6Relevant articles and documents
Catalytic Lewis acid phosphorylation with pyrophosphates
Fenton, Owen S.,Allen, Emily E.,Pedretty, Kyle P.,Till, Sean D.,Todaro, Joseph E.,Sculimbrene, Bianca R.
, p. 9023 - 9028 (2012/11/06)
We report a method for the Lewis acid catalyzed phosphorylation of alcohols with pyrophosphates. Ti(OtBu)4 was found to be the most effective catalyst in the phosphorylation of both primary and secondary alcohols with tetrabenzylpyrophosphate, providing conversions between 54% and >98% and isolated yields between 50% and 97%. Other pyrophosphates with orthogonal protecting groups were synthesized and screened to validate the generality of the approach. This study will describe how benzyl, methyl, ethyl, allyl, and o-nitrobenzyl pyrophosphates are all effective phosphorylating agents under Lewis acid catalysis.
Exploring specificity of glycosyltransferases: synthesis of new sugar nucleotide related molecules as putative donor substrates
Khaled, Amira,Piotrowska, Olga,Dominiak, Katarzyna,Auge, Claudine
, p. 167 - 178 (2008/09/19)
We investigated the specificity of glycosyltransferases toward donor substrates in two complementary directions. First we prepared simple N-acetyl-α-d-glucosamine 1-diphosphates: methyl-(2-acetamido-2-deoxy-α-d-glucopyranosyl)-diphosphate, benzyl-(2-acetamido-2-deoxy-α-d-glucopyranosyl)-diphosphate, 4-phenylbutyl-(2-acetamido-2-deoxy-α-d-glucopyranosyl)-diphosphate , by the coupling of the corresponding activated alkyl phosphates with N-acetyl-α-d-glucosamine 1-phosphate. These diphosphates as well as 2-acetamido-2-deoxy-α-d-glucopyranose 1-diphosphate, tested as donors of N-acetylglucosamine in a reaction catalyzed by Neisseria meningitidis N-acetylglucosaminyltransferase (LgtA), proved to be devoid of activity. Evaluated as inhibitors, only 2-acetamido-2-deoxy-α-d-glucopyranose 1-diphosphate showed some inhibitory activity with an IC50 value of 7 mM. In the second approach, we prepared sugar nucleotide mimics having the diphosphate bridge replaced by the oxycarbonylaminosulfonyl linker. The surrogate of GDP-Fuc was synthesized as a 9:1 α/β anomeric mixture, in 40% yield, starting from chlorosulfonyl isocyanate, perbenzylated l-fucopyranose, and a guanosine derivative, protected on the exocyclic amine and secondary hydroxyl functions of ribose. Then two deprotection steps, hydrogenolysis and enzymatic hydrolysis catalyzed by penicillin G amidase afforded the target molecule to be tested as fucose donor with recombinant human α-(1→3/4)-fucosyltransferase (FucT-III). Tested as a 4:1 α/β anomeric mixture, both in the absence and in the presence of cationic cofactors, this new guanosine fucose conjugate proved to be ineffective. Its inhibitory activity toward FucT-III evaluated through a competition fluorescence assay was very poor (IC50 value of 20 mM). The surrogate of UDP-GlcNAc that was already known as its protected acetylated derivative, tested as N-acetylglucosamine donor with LgtA in the presence of Mn2+ turned out not to be active either.
