The strong interaction of an octyl chain with M. smegmatis cells was paired with high specificity of the galactofuranose ring against mycobacteria growth.
辛基链与M. smegmatis细胞的强相互作用与半乳糖醛酸环对抗分枝杆菌生长的高特异性相配。
6-Deoxy-6-fluoro galactofuranosides: regioselective glycosylation, unexpected reactivity, and anti-leishmanial activity
作者:Jeane Vaugenot、Abderrafek El Harras、Olivier Tasseau、Rémi Marchal、Laurent Legentil、Boris Le Guennic、Thierry Benvegnu、Vincent Ferrières
DOI:10.1039/c9ob02596k
日期:——
Standard glycosylation of unprotected 6-fluorogalactofuranoside turned to three competitive reactions and afforded difuranosides able to impact growth of Leishmania tarentolae.
Direct activation of unprotected thioimidoyl furanosides yielded in only one step and few minutes a panel of rare uridine 5'-diphosphofuranoses. Diastereoselectivity of the reaction was tightly connected with reaction time, temperature, and nature of the furanosyl donor. This approach was totally selective since no ring expansion from the initial five-membered ring to the more stable pyranose form was observed.
Biocatalyzed synthesis of difuranosides and their ability to trigger production of TNF-α
Transglycosylation reactions biocatalyzed by the native arabinofuranosidase Araf51 and using D-galactosyl, D-fucosyl and 6-deoxy-6-fluoro-D-galactosyl derivatives as donors and acceptors provided di-to pentahexofuranosides. The immunostimulatory potency of these compounds, and more especially their ability to induce production of TNF-alpha, was evaluated on the murine macrophage cell line, Raw 264.7. The results obtained showed concentration-dependent and most importantly, structure-dependent responses. Interestingly, oligoarabinofuranosides belonging to the oligopentafuranoside family displayed concentration-, chain length and aglycon-dependent bioactivities irrespective of their fine chemical variations. Thus, neo-oligofuranosides in D-Galf series, as well as their D-Fucf and 6-fluorinated counterparts are indeed potential sources of immunostimulating agents. (C) 2016 Elsevier Ltd. All rights reserved.
A Chemoenzymatic Approach for the Synthesis of Unnatural Disaccharides ContainingD-Galacto- orD-Fucofuranosides
substrates were then used in AbfD3-catalysed hydrolyses to determine the parameters Km and kcat and in AbfD3-catalysed transglycosylation to evaluate their ability to serve as donor/acceptor. Four disaccharides were thus isolated and characterised, two resulting from -(1,2) connection along with two -(1,3)-regioisomers.