【作者】 杜林洳；

【导师】 徐翠莲；

【作者基本信息】 河南农业大学 ， 烟草学， 2011， 硕士

【摘要】 本文以便宜、易得的芳香醛和三氟乙酰乙酸乙酯为原料,利用简便的合成路线,合成了5种新的苯并吡喃杂环羧酸;采用枯斑法研究了其对烟草花叶病(Tobacco Mosaic Virus,TMV)的防治效果,筛选出了最优药剂;通过测定对感染烟草花叶病TMV的烟叶中叶绿素和相关防御酶活性的变化,初步了解了其对TMV的抗性机理,为开发新型、高效的抗病毒剂提供依据。结果如下:1.新型含氟苯并吡喃羧酸类化合物的合成:以水杨醛(取代水杨醛)和三氟乙酰乙酸乙酯为原料,以哌啶为催化剂,在无水乙醇中反应得到5种新的含氟苯并吡喃酯类化合物,产率80.2%~85.8%。将产品进一步在碱的醇溶液中水解、中和、分离得到5种含氟苯并吡喃羧酸类化合物,产率90.3%~95.7%。通过紫外光谱、红外光谱、核磁氢谱和碳谱进行了结构确认。该方法反应时间短、温度易控、操作简便、污染少等特点,是一个值得推广的绿色合成方法。2.苯并吡喃羧酸类化合物对TMV的诱导抗性:以心叶烟为材料,采用全叶法,对5种羧酸类化合物进行药效筛选试验,得到最优药剂。试验结果如下:总体上,各种药剂预防效果比治疗效果好。预防效果:2-羟基-2-三氟甲基-3,5-二氯-2H-苯并吡喃甲酸(2e)>2-羟基-2-三氟甲基-5-硝基-2H-苯并吡喃甲酸(2d)>2-羟基-2-三氟甲基-5-氯-2H-苯并吡喃甲酸(2b)>2-羟基-2-三氟甲基-5-溴-2H-苯并吡喃甲酸(2c)>2-羟基-2-三氟甲基-2H-苯并吡喃甲酸(2a)。当最优药剂的浓度为300μg/mL时,预防和治疗的抑制率分别为51.60%和44.41%,比市售抗病毒剂苯并噻二唑(BTH)分别高8.31%和1.62%。其次,通过在普通烟NC89上的病情指数试验得出:2-羟基-2-三氟甲基-3,5-二氯-2H-苯并吡喃甲酸(2e)>2-羟基-2-三氟甲基-5-氯-2H-苯并吡喃甲酸(2b)> 2-羟基-2-三氟甲基-5-硝基-2H-苯并吡喃甲酸(2d)>2-羟基-2-三氟甲基-5-溴-2H-苯并吡喃甲酸(2c)>2-羟基-2-三氟甲基-2H-苯并吡喃甲酸(2a),病情指数与枯斑抑制率的预防试验中效果最好的均为2-羟基-2-三氟甲基-3,5-二氯-2H-苯并吡喃甲酸。除2b、2d外,其余药剂的结果基本一致。3.植物体内酶活性的生化机制分析:经最优药剂(2e)(300μg/mL)处理后(T2),烟草叶片内的过氧化物酶(POD)活性高峰与对照苯并噻二唑(BTH 100μg/mL,T3)相比提前2d,活性峰值比BTH高0.82U/mg.min。这可能是由于施用最优药剂后,引起酚类物质氧化,木质素合成速度加快,提前达到高峰,进而引起POD活性提前达到高峰。最优药剂诱导的烟草叶片内的苯丙氨酸解氨酶(PAL)活性在接种后第9d达到最高峰,比BTH的最高活性值高22.56个酶活性单位。可能是药剂诱导刺激了机体,导致了控制PAL防御体系的基因表达量增加,促进了PAL催化的代谢产物大量合成,从而可以抵抗TMV的侵入、扩散。施用药剂后接种,烟草叶片内的多酚氧化酶(PPO)活性前期较低,从第2d开始,活性明显上升且高于其它任何处理。与BTH相比,活性高峰活性同时出现在第5d,最大峰值比BTH高97.88个酶活性单位。经最优药剂处理后接种(T2),过氧化氢酶(CAT)活性在接种后1d就达到高峰值(87.27),而其它处理的CAT活性均在第5d达到高峰。最优药剂处理后接种的烟株超氧化物歧化酶(SOD)活性峰值比BTH处理后接种晚2d出现,其酶活性最大峰值高出3.64个酶活性单位。更多还原

【Abstract】 Five new benzopyran carboxylic acid containing fluorine were synthesized from cheap, easily available aromatic aldehyde and trifluoroacetyl ethyl acetate by simple synthetic route. The inhibition effect on Tobacco Mosaic Virus(TMV) was studied through the Necrotic lesions test and the optimal agent was screened out. The resistant mechanism of the optimal agent to TMV was preliminary studied by testing related defense of chlorophyll and related enzyme activities in tobacco infected by TMV to provide evidence for the development of new, effective antiviral agents. Results are as follows:1. Synthesis of novel benzopyran acids containing fluorine:Five new benzopyran esters was obtained from the reaction of salicylaldehyde and trifluoroacetyl ethyl acetate in the presence of piperidine with the yield of 80.2% - 85.8%. Then 5 benzopyran carboxylic acid containing trifluoine were achieved in the yield of 90.3% - 95.7% after the esters were further hydrolyzed, neutralized and isolated in the alcohol solution of alkali. The structures are confirmed by UV, IR, 1H NMR and 13C NMR. The method has such advantages as short reaction time, easy controlled temperature, simple operation and less pollution, etc.2. The induction resistance of benzopyran acids on TMV:The optimal agent was screened by the resistant test of 5 carboxylic acid compounds on Nicotiana glutinosa as the materials using the whole leaf method. The results are as follows: On the whole, the preventive effect of various agents is better than curative effect. Preventive effect: (2e)> (2d)> (2b)> (2c)> (2a)., The rate of prevention and curation of the inhibition rates were respectively 51.60% and 44.41% when the concentration of optimal agent is 300μg/mL, which are higher by 8.30% and 1.11% compared with commercially available antiviral agents benzothiadiazole (BTH). Secondly, the disease index on tobacco NC89 experiment showed: (2e)> (2b)> (2d)> (2c)> (2a). In the disease index and the inhibition effect of prevention trials, 2e is the best agent. The rest are the same basically on the pharmaceutical results besides 2b and 2d.3. The biochemical mechanism analysis of preventive enzymes:After the treatment by optimal agent (2e) (300μg/mL) (T2), the peroxidase (POD) activity peak of tobacco leaves reached earlier by two days compared with the benzothiadiazole (BTH 100μg/mL, T3) control, and the activity peak is higher more 0.82U/mg.min than BTH. This may be due to the cause of oxidation of phenolic compounds and the production of lignin faster after application of the best agents to the inoculated tabacco and then rise to peak ahead of POD activity. Tobacco leaves phenylalanine ammonia-lyase (PAL) activity reach to the peak on the 9th day after application of the best agents to the inoculated tabacco, which is the same as BTH and higher than the highest peak of BTH by 22.56 activity units. The reason may be that gene expression increase controlling the PAL and that promoted a large number of PAL-catalyzed synthesis of metabolites after being stimulated on the body with the agent, which can resist the invasion and the proliferation of TMV. The polyphenol oxidase (PPO) activity of tobacco leaves is very low in the first day after being applied the best agent to the inoculaed tobacco. The activity was significantly increased and higher than any other treatment from the 2th. Compared with BTH, the activity peak appeared at the same day on the 5th, and the maximum activity peak is higher by 97.88 units than BTH. The catalase (CAT) activity got to peak value (87.27) on the first day after the tobacco leaves was treated by optimal agent then being inoculated (T2). The CAT activity of other treatments reaches to peak on the 5th day. The superoxide dismutase (SOD) activity peak of tobacco treated with optimal agent after inoculating occurs later by two days than BTH, and the activity peak is higher by 3.64 units.更多还原