title: Synthesis, Herbicidal Activity, and QSAR of Novel N-Benzothiazolyl- pyrimidine-2,4-diones as Protoporphyrinogen Oxidase Inhibitors.
abstract: Protoporphyrinogen oxidase (PPO, E.C. 1.3.3.4) is known as a key action target for several structurally diverse herbicides. As a continuation of our research work on the development of new PPO-inhibiting herbicides, a series of novel 3-(2'-halo-5'-substituted-benzothiazol-1'-yl)-1-methyl-6-(trifluoromethyl)pyrimidine-2,4-diones 9 were designed and synthesized. The bioassay results indicated that a number of the newly synthesized compounds exhibited higher inhibition activity against tobacco PPO (mtPPO) than the controls, saflufenacil and sulfentrazone. Compound 9F-5 was identified as the most potent inhibitor with a Ki value of 0.0072 μM against mtPPO, showing about 4.2-fold and 1.4-fold higher potency than sulfentrazone (Ki = 0.03 μM) and saflufenacil (Ki = 0.01 μM), respectively. An additional green house assay demonstrated that compound 9F-6 (Ki = 0.012 μM) displayed the most promising postemergence herbicidal activity with a broad spectrum even at a concentration as low as 37.5 g of active ingredient (ai)/ha. Maize exhibits relative tolerance against compound 9F-6 at the dosage of 150 g ai/ha, but it is susceptible to saflufenacil even at 75 g ai/ha. Thus, compound 9F-6 exhibits the potential to be a new herbicide for weed control in maize fields.
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University , Wuhan 430079, P. R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zuo
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University , Wuhan 430079, P. R. China.
authors.forename: Qiongyou
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University , Wuhan 430079, P. R. China.
authors.forename: Sun-Wen
authors.initials: SW
authors.lastname: Su
authors.affiliation: State Key Laboratory of Elemento-Organic Chemistry, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Cong-Wei
authors.initials: CW
authors.lastname: Niu
authors.affiliation: State Key Laboratory of Elemento-Organic Chemistry, Nankai University , Tianjin 300071, P. R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Xi
authors.affiliation: Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University , Wuhan 430079, P. R. China.
authors.forename: Guang-Fu
authors.initials: GF
authors.lastname: Yang
mesh_terms: D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D006540:Herbicides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D007700:Kinetics; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D050768:Protoporphyrinogen Oxidase / Q000737:chemistry* / Q000378:metabolism; D011744:Pyrimidinones / Q000737:chemistry / Q000494:pharmacology; D021281:Quantitative Structure-Activity Relationship; D013449:Sulfonamides / Q000737:chemistry / Q000494:pharmacology; D014026:Nicotiana / Q000187:drug effects / Q000201:enzymology*; D014230:Triazoles / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D006540:Herbicides; D010940:Plant Proteins; D011744:Pyrimidinones; D013449:Sulfonamides; D014230:Triazoles; C552482:N'-(2-chloro-4-fluoro-5-(3-methyl-2,6-dioxo-4(trifluoromethyl)-3,6-dihydro-1(2H)-pyrimidinyl)benzoyl)-N-isopropyl-N-methylsulfamide; C475571:N-(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide; D050768:Protoporphyrinogen Oxidase
keywords: benzothiazole; herbicide; molecular design; protoporphyrinogen oxidase; pyrimidinedione