5-酰基巴比妥酸衍生物的设计、合成及除草活性和分子作用机制研究

Design, Synthesis and Herbicidal Activity of 5-Acylbarbituric Acid Derivatives and Study of Molecular Mode of Action

为了开发含有巴比妥酸结构的新型β-三酮类除草剂,设计、合成了一系列5-酰基巴比妥酸衍生物,并测试了其除草活性.温室盆栽测试结果表明,在1500g·ha^-1的剂量下,目标化合物1,3-二甲基-5-(2-(2-氯-4-氟苯氧基)-1-羟基亚乙基)嘧啶-2,4,6(1H,3H,5H)-三酮(BBA-22)和1,3-二甲基-5-(2-(2-溴-4-氟苯氧基)-1-羟基亚乙基)嘧啶-2,4,6(1H,3H,5H)-三酮(BBA-27)对所测杂草均具有优异的抑制活性.其中,化合物BBA-22在苗前处理187.5g·ha^-1的剂量下,对油菜、苋菜和马唐具有很好的抑制活性,其活性优于商品除草剂2,4-二氯苯氧乙酸(2,4-D).另外,以拟南芥为模型植物的分子作用机制研究表明,化合物BBA-22在植物体中被降解为相应的苯氧乙酸,这解释了其与生长素类除草剂具有相似除草机理的原因.本工作的研究结果表明,化合物BBA-22是其相应的苯氧乙酸生长素类除草剂的前药,可以用作进一步开发新型生长素型除草剂的先导化合物.

In an effort to develop novelβ-triketone herbicides containing a barbituric acid moiety,a series of 5-acylbarbituric acid derivatives were designed,synthesized,and tested for herbicidal activity.The bioassay results showed that some of the target compounds,such as 5-(2-(2-chloro-4-fluorophenoxy)-1-hydroxyethylidene)-1,3-dimethylpyrimidine-2,4,6(1 H,3 H,5 H)-trione(BBA-22)and 5-(2-(2-bromo-4-fluorophenoxy)-1-hydroxyethylidene)-1,3-dimethylpyrimidine-2,4,6(1 H,3 H,5 H)-trione(BBA-27),exhibited excellent herbicidal activity against all tested weeds at a dosage of 1500 g·ha^-1.In particular,compound BBA-22 displayed good pre-emergent herbicidal activity against Brassica campestris,Amaranthus retroflexus and Digitaria sanguinalis even at a dosage of 187.5 g·ha^-1,surpassing that of a commercial herbicide 2,4-dichlorophenoxyacetic acid(2,4-D).Investigation of the molecular mode of action of compound BBA-22 upon treatment of Arabidopsis thaliana as a model plant revealed that BBA-22 was degraded to the corresponding phenoxyacetic acid,which explains why the herbicidal mechanism is similar to that of auxin-type herbicides.The present study demonstrates that compound BBA-22 is a proherbicide of the corresponding phenoxyacetic acid auxin herbicide and a potential lead compound for further development of novel auxin herbicides.