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 One and two central GlcNAc residues of the chitin backbone have been replaced by Glc units.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.