Novel Plant Activators:Designing And Synthesis, Activity Screening And The Transduction Process Study

This dissertation aimed at the research and development of plant activators with novel structures. Two series of novel plant activators were designed and synthesized based on benzo[1,2,3]thidiazole-7-carboxylates (BTH:7-COSCH3; B-2a:7-COOCH2CF3). The transduction process of these compounds was studied by introducing amino group onto the5-position of B-2a with fluorescence imaging method.Lead compounds from CADD methods by comparisons of molecular3-D structures and pharmacophore similarities of known plant activators were discovered, some potential novel structures were derived. The preliminary activity was studied to evaluate the potential applications as plant activators.1. A series of novel plant activators were synthesized based on the commercial plant activator BTH by introducing alkyl chain of different lengths and various aromatic moieties to its ester group. The bioassay for the inhibition of seven different plant diseases showed that the compounds with alkyl chain of3-4carbon had good activity, and the compounds with of2,4-D had better activity. The result was helpful for the structure-activity study of the derivatives of BTH.2. A fluorescent derivative of potent plant activator B-2a was developed by introducing amino group on the5-position of BTH and applied for the monitoring of the transduction process of plant activator. The results showed that the compound could transfer rapidly from foliage to root. This preliminary study proved the up-to-down transportation manner of this plant activator.3. Novel plant activator derivatives including thieno[1,2,3]thidiazole-6-carboxylate and4-benzylpyrrol[1,2,3]thiadiazole-6-carboxylate derivatives were developed. Bioassay tests showed that the compounds with6-COOCH3,6-COOCH2CH3, and6-COOCH2CF3to the thieno[1,2,3]thidiazole-6-carboxylate was beneficial for the activity and3potential compounds with high activity were obtained.4. Novel potential plant activators were discovered from lead compounds optimization, a series of derivatives from6-ethoxy-7-methyl-6H-[1,2,5]oxadiazolo[3,4-e]indole-8-carboxylate was synthesized. Bioassay results illustrated that some of the novel compounds had high activity to inhibit some test diseases, while had low in-vitro fungicidal activities. Therefore, these novel compounds had characteristics of potential plant activators.5. The applications of thieno[1,2,3]thidiazole-6-carboxylate derivatives as plant cell culture elicitors for the production of secondary metabolites were evaluated in grapevine. The results showed that the compounds methyl thieno[1,2,3]thidiazole-6-carboxylate (S1) and2,2,3,3,3-pentafluoropropyl thieno[1,2,3]thidiazole-6-carboxylate (S5) could significantly increase the yield of trans-resveratrol,even more potent than that of commonly used elicitor MeJA and other positive controls.It implied that these compounds can be used as novel cell culture elicitors.