title: Design, synthesis and herbicidal activities of novel 4-(1H-pyrazol-1-yl)-6-(alkynyloxy)-pyrimidine derivatives as potential pigment biosynthesis inhibitors.
abstract: BACKGROUND
  With the objective of finding novel valuable herbicidal candidates, a series of novel 4-(1H-pyrazol-1-yl)-6-(alkynyloxy)-pyrimidine derivatives were synthesised and their herbicide activities were evaluated in vivo.
  
  
  RESULTS
  The results showed that many target compounds expressed bleaching activities. Among these, compound 5 h showed the best bleaching activity to gramineous weeds, being able to produce the highest inhibition of chlorophyll level in seedlings of Pennisetum alopecuroides L. (IC50 = 3.48 mg L(-1) ). Moreover, compound 5 h expressed good selective toxicity between gramineous P. alopecuroides L. and broadleaf plant Brassica campestris L.
  
  
  CONCLUSIONS
  The present work demonstrates that pyrimidine derivatives containing pyrazole can be used as potential lead compounds for developing novel pigment biosynthesis inhibitors.
authors: Department of Plant Protection, College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei, China.
authors: Hong-Ju
authors: HJ
authors: Ma
authors: Jian-Hua
authors: JH
authors: Zhang
authors: Xiang-Dong
authors: XD
authors: Xia
authors: Meng-Han
authors: MH
authors: Xu
authors: Jun
authors: J
authors: Ning
authors: Jian-Hong
authors: JH
authors: Li
mesh_terms: D001937:Brassica / Q000187:drug effects; D002734:Chlorophyll / Q000096:biosynthesis; D006540:Herbicides / Q000138:chemical synthesis* / Q000633:toxicity*; D031782:Pennisetum / Q000187:drug effects; D057685:Plant Weeds / Q000187:drug effects*; D011743:Pyrimidines / Q000138:chemical synthesis* / Q000633:toxicity*
chemical_list: D006540:Herbicides; D011743:Pyrimidines; D002734:Chlorophyll
keywords: bleaching herbicidal activity; chlorophyll; pigment biosynthesis inhibitors; pyrimidine