[alpha]-Nucleosides differ from the natural [beta]-ones by the inversion of the configuration at the C(1') anomeric position of the furanose
ring (Figure 10, 6) (for a review, see ).
Encouraged by these results and to compare biological activities of monosaccharide (furanose
and pyranose form) benzoates with that of disaccharide (e.g.
, carbocyclic and heterocyclic analogues," Current Medicinal Chemistry, vol.
(b) The use of certain furanose
sugars, which can also be substrates for KHK and compete with fructose for its metabolism to hexose-1-phosphate .
3B) is assigned to the first overtone of the fundamental CH stretching vibrational mode and is due to the furanose
or pyranose ring (invariable constituent of hemicellulose).
The absorption bands at [lambda]=1672 nm and 1712 nm are also due to CH in the aromatic skeletal and furanose
(or pyranose) regions (Osborne and Fearn 1988, Williams and Norris 1990, Siesler et al.
1) are a novel class of bicyclic DNA analogs in which the 2' and 4' positions in the furanose
ring are joined via an O-methylene (oxy-LNA), S-methylene (thio-LNA), or amino-methylene (amino-LNA) moiety (20-24).
Thus, the enzyme transferring arabinose in furanose
form or glucuronic acid to the flavonols may be missing or not functioning in all clones.
For grasses, the mode of attachment seems to be highly conserved, with the acid group esterified to the primary hydroxyl formed at the C5 position when arabinose is in the furanose
Due to the twisted conformation of the furanose
rings, the dihedral angle between the H-2 and H-3 protons is usually 90[degrees] and, hence, in the spectra of compound 2, the coupling constant between H-2 and H-3 is 0 Hz.