N-(5’-溴-4’-取代嘧啶-2'-基)苯磺酰脲化合物的合成和生物活性

Synthesis and Bioactivity of N-(5’-Bromo-4’-substituted pyrimidin-2’-yl)phenyl Sulfonylurea

乙酰羟基酸合成酶(Acetohydroxyacid synthase,AHAS,EC4.1.3.18)是植物和微生物中亮氨酸、异亮氨酸和缬氨酸合成途径的一个关键酶,以AHAS为靶标的磺酰脲类除草剂具有高效、高选择性和对环境友好的特点.通过2-氨基-4-甲基嘧啶溴代反应以及进一步的衍生、磺酰基异氰酸酯的胺解,合成了一系列含有5-溴嘧啶基的新磺酰脲.其结构经1HNMR、质谱和元素分析确定.生物活性测试表明目标化合物在离体水平对大肠杆菌乙酰羟基酸合成酶同工酶AHASII表现出了与市售除草剂苯磺隆相当甚至更优的抑制活性,而盆栽除草活性低于苯磺隆.

Acetohydroxy acid synthase （AHAS） catalyzes the key reactions in the biosynthesis pathways of branched-chain amino acids （valine, isoleucine and leucine） in plants and microorganisms, and sulfonylurea herbicides are inhibitors of AHAS, characterized by high herbicidal activity, high degree of selectivity, and excellent environmental safety. A series of 5-bromopyrimidinyl-containing new sulfonylureas have been synthesized through bromination of 2-amino-4-methyl pyrimidine, followed by further modification and then coupled with sulfonyl isocyanate. Their structures were confirmed by 1H NMR, MS techniques and elemental analysis. Preliminary bioassay of sulfonylureas showed that the title compounds exhibited good in vitro activities against E. coli acetohydroxy acid synthase isoenzyme AHASII but showed lower herbicidal activities in vivo, compared with commercial herbicide tribenuron-methly.