Study On The Formation Mechanism Of Phenolic Phytoalexins From The Resin Of Dracaena Cochinchinensis

This paper comprises four chapters altogether. The first chapter of the chemical constituents of phytoalexins from the plants was reviewed. The second chapter reviewed the chemical constituents of the red resin of Dracaena cochinchinensis and discussed the studies on the chemical composition from the red resin of D. cochinchinensis, then study phenolic constituents from Chinese Dragon’s Blood and its ultraviolet spectrum characteristic.The third chapter illustrated the antibacterial activities of phenolic constituents against Staphylococcus aureus and Escherichia coli,and then study the formation mechanism of phenolic phytoalexins from the resin of D. cochinchinensis. And in the last chapter, conclusion of this dissertation is made.Dragon’s blood is a deep red resin, which has been used as a precious traditional medicine as well as a colorant in works of art by many cultures since ancient times. In the course of searching for more new natural compounds and investigated the formation mechanism of the red resin of D. cochinchinensis, we further systematically investigated the red resin of D. cochinchinensis, which led to the isolation and elucidation of fouty-three compounds.Different phenolic constituents from Chinese Dragon’s Blood have especially ultraviolet spectrum characteristic by the contrastive analysis of the Ultraviolet Spectrum. The method can be applied to extraction and isolation a type of phenolic constituents from dragon’s blood.Most of the phenolics have antimicrobial activity against S. aureus and E. coli0157:H7.Ethyl-p-hydroxy benzoate was found to be most efficacious against S. aureus and E. coli0157:H7. Phenolic compounds were almost undetectable in the fresh stem xylem of D. cochinchinensis, but were induced and accumulated dramatically in the dragon’s blood resin after wounding and microbial infection. On the basis of the results of phytochemical study and the antibacterial activities against Staphylococcus aureus and Escherichia coli, these compounds would play a vital role in the defense strategy of D. cochinchinensis by wounding. These results imply that phenolic compounds of the dragon’s blood resin are a special group of phytoalexins.