191019-11-1

Relevant academic research and scientific papers

Synthesis and biological evaluation of oligosaccharides related to the molecule signals in plant defence and the Rhizobium-legume symbiosis

The synthesis of tetrasaccharides related to the chitinoligosaccharides involved in plant defence and Rhizobium-legume symbiosis is reported. One and two central GlcNAc residues of the chitin backbone have been replaced by Glc units. A biological evaluation using Catharanthus roseaus assay indicates that the replacement of the two central units produces a total loss of activity. However, the replacement of the GlcNAc moiety close to the reducing end by Glc in the chitin tetramer, does not reduce its activity.

Synthesis and conformational analysis of a lipotetrasaccharide related to the nodulation factor of Rhizobium bacteria

The synthesis of the lipotetrasaccharide glycoside, p-methoxyphenyl O-{2-deoxy-2-[(11Z)-11-octadecenoylamido]-β-D- glucopyranosyl}-(1→4)-O-(β-D-glucopyranosyl)-(1→4) O-β-D-glucopyranosyl)-(1→4)-2-acetamido-2-deoxy-β-D- glucopyranoside 16, starting from acetobromocellobiose is reported. Compound 16 is an analogue of the nodulation factors of Rhizobium bacteria having the central chitobiose unit substituted by a cellobiose unit. A conformational study indicates that 16 have restricted fluctuations around the glycosidic torsion angles, but can adopt a variety of shapes.