| abstract |
An essentially pure substance has a structure of a Nod factor or one of its analogues. The Nod factor is characterized by the fact that its biosynthesis is controlled by at least one nodulation gene ($i(nodA,B,C)) common to the Rhizobiaceae, in particular to the genera $i(Rhezobium), $i(Bradyrhizobium), $i(Sinorhizobium) and $i(Azorhizobium). This substance consists of a lipo-oligosaccharide which is not a derivative of the exopolysaccharides and which has the general formula (I). In formula (I), the Nod factor of which it has the strucutre is a plant-specific symbiotic signal and is capable of enhancing the capacity of the bacteria to infect the host plant with which it is associated and/or of accelerating the formation of nodules on the host plant with which it is associated and/or of inducing the transcription of symbiotic genes of the Leguminoseae. Applications to the treatment of plants and as an active therapeutic agent in humans and animals. G stands for a hexosamine variously substituted, for example by an acetyl group on the nitrogen, a sulphate group, an acetyl group and/or an ether group on oxygen R1?, R2?, R3?, R5?, R6?, R7?, which may be identical or different, stand for H, CH3?CO-, CX?HY?CO- where X is a whole number between 0 and 17 and Y is a whole number between 1 and 35, or any other acyl group, for example a carbamyl groupe, R4? stands for a saturated or mono-, di, or tri-unsaturated aliphatic chain containing at least 12 carbon atoms and n is a whole number between 1 and 4. |