胜红蓟化感作用研究Ⅶ.胜红蓟素类似物的合成及其对植物与微生物的抑制作用

合成了5种胜红蓟素的结构类似物，将它们与胜红蓟素在对植物和微生物的抑制活性上进行了比较。结果表明，在100mg/l浓度时，对于萝卜和黑麦草两种受体，类似物6－甲酰基－7－甲氧基2，2－二甲基－2H－苯并吡喃和7－羟基－6－甲酰基－3，4－二氢－2，2－二甲基－2H－苯并吡喃较胜红蓟素有更强的抑制作用，尤其是对受体 根长的抑制作用达到显著，这两种类似物同时也具有较强的抗菌活性，在400mg/l浓度下，它们对两种真菌：水稻纹枯病菌和辣椒疫霉病菌的抑制率达到100％；在2000mg/l浓度下，7－羟基－6－甲酰基－3，4－二氢－2，2－二甲基－2H－苯并吡喃还对两种细菌：水稻白叶枯病菌和水稻基腐病菌有较强的抑制作用。研究揭示了构成胜红蓟素基本结构的2，2－二甲基－2H－苯并吡喃对植物无明显抑制作用，对微生物的抑制作用也不强，但当其6位或7位带有活性取代基后，对植物和微生物抑制作用都显著增强。

Allelopathy of Ageratum conyzoides L.

Five analogs of ageratochromene were synthesized and their inhibitory effect on plants and microorganisms were compared with that of ageratochromene. Results showed that two analogs,6 formyl 7 methoxyl 2,2 dimethy1 2H benzopyran and 7 hydroxyl 6 formyl 3,4 dihydro 2,2 dimethyl 2H benzopyran had higher inhibitory effects on two plants:radish and ryegrass than that of ageratochromene at concentration of 100mg/l,especially inhibited the root growth of plants significantly.They also possessed stronger antimicrobial activity and the inhibitory rates for two fungi( Rhizoctonia solani and Phytophthora capsici) were 100% at concentration of 400mg/l,moreover,7 hydroxyl 6 formyl 3,4 dihydro 2,2 dimethyl 2H benzopyran inhibited two bacteria species significantly: Xanthomonas oryzae pv. oryzae and Erwinia chrysanthemi at concentration of 2000mg/l.Researches revealed that 2,2 dimethyl 2H benzopyran,the basic structure of constituting ageratochromene was not correlated with its allelopathic and antimicrobial effecs.However,as there were active substituents at its 6 or 7 position,both effects were strengthen significantly.