7 research outputs found
Identification of lignin oligomers in Kraft lignin using ultra-high-performance liquid chromatography/high-resolution multiple-stage tandem mass spectrometry (UHPLC/HRMSn)
Synthesis of the Zwitterionic Repeating Unit of the O-Antigen from Shigella sonnei and Chain Elongation at Both Ends
International audienceShigella sonnei O-antigen features a zwitterionic disaccharide repeat encompassing two rare monosaccharides. The synthesis of the AB repeat and of trisaccharides ABA' and B'AB, which validates chain elongation at either end, is reported. All targets were synthesized using a postglycosylation oxidation strategy in combination with imidate chemistry. Precursors to residue A were obtained from L-glucose. The AAT (B) donor and acceptor were obtained from D-glucosamine. A one-step Pd(OH)2/C-mediated deprotection provided the propyl glycoside targets
A comparison of different oxidative pretreatments on polysaccharide hydrolyzability and cell wall structure for interpreting the greatly improved enzymatic digestibility of sugarcane bagasse by delignification
On the anomalous temperature dependence of cellulose aqueous solubility
The solubility of cellulose in water-based media is promoted by low temperature, which may appear counter-intuitive. An explanation to this phenomenon has been proposed that is based on a temperature-dependent orientation of the hydroxymethyl group. In this paper, this hypothesis is investigated using molecular dynamics computer simulations and NMR spectroscopy, and is discussed in conjunction with alternative explanations based on solventâsolute and solventâsolvent hydrogen bond formation respectively. It is shown that neither simulations nor experiments lend support to the proposed mechanism based on the hydroxymethyl orientation, whereas the two alternative explanations give rise to two distinct contributions to the hydration free energy of cellooligomers