7364-99-0

Upstream product

• 13089-27-5 p-nitrophenyl 2-acetamido-2-deoxy-3,4,6-tri-O-acetyl-β-D-glucopyranoside 
• 7284-20-0 p-Nitrophenyl-2-acetamido-3,4-di-O-acetyl-2-deoxy-6-O-trityl-β-D-glucopyranosid 

Downstream Products

• 81561-99-1 p-nitrophenyl 2-acetamido-2-deoxy-6-O-β-L-fucopyranosyl-β-D-glucopyranoside 
• 1311146-68-5 p-nitrophenyl 2-acetamido-3-O-acetyl-2,4-dideoxy-α-L-threo-hex-4-enodialdo-1,5-pyranoside 

Relevant academic research and scientific papers

4-deoxy-substrates for β-N-acetylhexosaminidases: How to make use of their loose specificity

β-N-Acetylhexosaminidases feature so-called wobbling specificity, which means that they cleave substrates both in gluco-and galacto-configurations, with the activity ratio depending on the enzyme source. Here we present the new finding that fungal β-N-acetylhexosaminidases are able to hydrolyze and transfer 4-deoxy-N-acetylhexosaminides with high yields. This clearly demonstrates that the 4-hydroxy moiety at the substrate pyranose ring is not essential for substrate binding to the enzyme active site, which was also confirmed by molecular docking of the tested compounds into the model of the active site of β-Nacetylhexosaminidase from Aspergillus oryzae. A set of four 4-deoxy-N-acetylhexosaminides was synthesized and screened against a panel of β-N-acetylhexosaminidases (extracellular and intracellular) from various sources (fungal, human, animal, plant and bacterial) for hydrolysis. The results of this screening are reported here, as well as the structures of three novel 4′-deoxy-disaccharides prepared by transglycosylation reaction with high yields (52% total disaccharide fraction) using β-N-acetylhexosaminidase from Talaromyces flavus. The Author 2010. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org.

Regioselective monohydrolysis of per-O-acetylated-1-substituted-β-glucopyranosides catalyzed by immobilized lipases

The regioselective monohydrolysis of different peracetylated-β-glucopyranosides in aqueous media using immobilized preparations of three different lipases-those from Aspergillus niger (ANL), Candida rugose (CRL) and Candida antarctica B (CAL-B)-has been studied. Three very different immobilization strategies-covalent attachment, anionic exchange and interfacial activation on a hydrophobic support-were employed for each lipase. The role of the immobilization strategy and the effect of the presence of different moieties in the anomeric position of the substrate on the hydrolytic activities, specificities and regioselectivities of the lipases were investigated. For example, the PEI-ANL preparation exhibited 800 times higher activity than the octyl-ANL in the hydrolysis of 2-acetamido-2-deoxy-1-(4-nitrophenyl)-3,4,6-tri-O-acetyl-β-d-glucopyranoside-producing 4-OH derivative in 18% yield-whereas the octyl-ANL was five times more active than the PEI-ANL in the hydrolysis of 1-(4-nitrophenyl)-2,3,4-tri-O-acetyl-β-d-xylopyranoside, producing 4-OH monohydroxy product in >99% yield. The octyl-CRL preparation hydrolyzed regioselectively 3,4,6-tri-O-acetyl-glucal in position 6 in 68% yield while the PEI-CRL produced the 3-OH product in 11% yield, although with moderate specificity. The CNBr-CAL-B hydrolyzed specifically and regioselectively the glucal producing the 3-OH product in >99% yield.