新型吡唑双酰肼类化合物的合成及除草活性

为了寻找具有较高除草活性的农药先导化合物,将吡唑环与双酰肼结构进行拼接,设计合成了13个未见报道的含吡唑环的双酰肼类目标化合物6a~6m,其结构均通过核磁共振氢谱及高分辨质谱确认。培养皿法测定结果表明:在200 mg/L下,化合物N'-(2-(2,4-二氯苯氧基)乙酰基)-3-(二氟甲基)-1-甲基-1H-吡唑-4-甲酰肼(6i)对小麦Triticum aestivum、油菜Brassicacampestris、高粱Sorghum bicolor、萝卜Raphanus sativus和黄瓜Cucumis sativus根、茎的抑制率均达80%以上。盆栽试验表明:在有效成分150 g/hm2剂量下,采用苗后茎叶喷雾处理,化合物6i对反枝苋Amaranthus retroflexus和鳢肠Eclipta prostrata的抑制率均达80%;相同剂量下采用苗前土壤喷雾处理,6i对反枝苋A. retroflexus的抑制率也达80%。     

含咪唑啉酮结构的吡唑类对羟基苯基丙酮酸双加氧酶抑制剂的除草活性及选择性研究

对羟基苯基丙酮酸双加氧酶（HPPD）是一种重要的除草剂作用靶标。为了发现具有高活性和高选择性的新型HPPD抑制型除草剂,对前期合成的23个含咪唑啉酮结构单元的吡唑类衍生物（2A~2W）进行了深入的生物活性评价和构效关系研究,比较了它们对拟南芥HPPD（AtHPPD）和人源HPPD（hHPPD）抑制活性的差异,从酶水平上总结了该类化合物的结构-活性关系和种属选择性规律,从活体植株水平研究了它们的除草活性。结果表明:部分化合物表现出良好的除草活性和作物安全性,其中化合物2E和2G在150 g/hm2剂量下对荠菜、繁缕、小藜和棒头草抑制活性达到80%以上,且其对作物的安全性也明显优于商品化除草剂硝磺草酮。此外,化合物2P在酶水平上的选择性倍数高达93倍,展示出良好的应用潜力。     

新型喹唑啉-4(3H)-酮Schiff碱的合成及生物活性

为探索具有高杀菌活性的新型喹唑啉酮类先导化合物,以4-氯-2-氨基苯甲酸为起始原料,经重氮化、叠氮化、酯化等系列反应,得到17个未见文献报道的喹唑啉-4(3H)-酮Schiff碱类化合物。所有目标化合物的结构均经IR、1H NMR、MS及元素分析确证。初步生物活性测定结果表明,目标化合物表现出一定的杀菌活性,特别是对芒果褐色蒂腐病菌Phomopsis mangiferae Ahmad活性较好。化合物7-氯-3-(2,4-二氯-苯基)亚氨乙基-2-苯氨基喹唑啉-4(3H)-酮 (7e) 在 100 μg/mL 时,对橡胶棒孢霉叶斑病菌Corynespora cassiicola Wei和芒果褐色蒂腐病菌Phomopsis mangiferae Ahmad的抑制率分别为26.21%±1.11%和98.18%±1.07%,与对照药剂百菌清(25.64%±1.31%和100%)相当。初步的构效关系表明,吸电子基团有利于提高目标化合物的杀菌活性。     

酮醇酸还原异构酶抑制剂的设计、合成及除草活性

酮醇酸还原异构酶(KARI)是一个有前景的除草剂靶标酶,有关其抑制剂的设计研究鲜有报道。在文献报道的菠菜KARI酶复合物0.165 nm高分辨率晶体结构基础上,利用分子对接DOCK 4.0方法进行MDL/ACD三维数据库搜寻,得到了279个与KARI酶结合能较低的小分子结构信息,并从中选取部分小分子进行化学合成,进而测试了其除草活性。在合成的17个化合物中,发现个别化合物对油菜 (抑制率70.8 %) 和稗草 (抑制率48.8 %)具有较好的生长抑制活性。     

含大体积取代基的吡唑并三嗪酮类化合物的合成及除草活性

以1-(取代)苯基-5-氨基-1H-吡唑-4-甲酸乙酯或1-叔丁基-5-氨基-1H-吡唑-4-甲酰氯和2-甲基-4-炔丙基-6-氨基-7-氟-2H-苯并[b][1,4]-噁嗪-3(4H)-酮为初始原料,分别通过不同的合成路线,得到22个未见文献报道的含大体积取代基的吡唑并三嗪酮类化合物,所有化合物的结构均通过核磁共振氢...     

取代双吡唑类化合物的合成及杀虫活性

以3-氯苯肼盐酸盐( 1 )和1,1,3,3-四甲氧基丙烷( 2 )为起始原料,经环化、Vilsmeier反应得1-(3-氯苯基)-1H-吡唑-4-甲醛( 4);(4 )与3-三氟甲基苯乙酮( 5 )经Claisen-Schmidt缩合反应得取代芳基烯酮类化合物( 6 ),再与水合肼发生环化反应得3-(3-三氟甲基苯基)-5-(3-氯苯基-1H-吡唑)-4,5-二氢吡唑( 7),其与取代异氰酸酯 作用,制得15个未见文献报道的结构新颖的取代双吡唑类化合物。利用核磁共振氢谱(1H NMR)和质谱(MS)对其结构进行了表征。初步生物活性测定结果表明,在 500 mg/L 质量浓度下,部分化合物对小菜蛾Plutella xylostella的致死率达100%,而对苜蓿蚜Aphis medicaginis、稻褐飞虱Nilaparvata lugens、朱砂叶螨Tetranychus cinnabarinus均无杀虫活性。     

1-(吡唑-5-酰基)-1H-取代吡唑的合成及生物活性

为了寻求新的含吡唑双杂环先导化合物,用4-取代-1-甲基-3-乙基-5-吡唑甲酰氯与3-甲基-5-吡唑酮、3-乙基-5-吡唑甲酸乙酯等含氮杂环反应得到了8个新的含吡唑环的双杂环类化合物。经IR、1H NMR、MS和元素分析对化合物的结构进行了表征。初步生物活性实验结果表明:在25 μg/mL浓度下, 5d 对水稻稻瘟病菌Pyricularia oryzae的抑制率为45.6%;在500 μg/mL浓度下, 5c 对稻黑尾叶蝉Nephotettix cincticeps的死亡率为53.9%。     

新吡唑啉类化合物的分子设计、合成及生物活性

设计并合成了10个未见文献报道的标题化合物,其化学结构经元素分析、1H NMR和GC-MS分析确认。初步生物活性测试结果表明,部分化合物显示出较好的杀菌活性。     

2-杂环基-1,3,4-噁二嗪酮类化合物的合成及其除草活性

以取代杂环羧酸为起始原料,在1,3,4-噁二嗪-5-酮的2-位上分别引入呋喃环、吡啶环及氯代噻吩环,合成了31个未见报道的2-杂环基-1,3,4-噁二嗪酮化合物,其化学结构经核磁共振氢谱和元素分析确证。初步的生物活性测定结果表明,该类化合物具有良好的除草活性,如在质量浓度200 mg/L时,化合物 E14、E16、E20、E21 对马唐Digitaria sanguinalis的抑制率大于90%,化合物 E06、E07、E10、E14、E16、E20 对苋菜Ambrosia tricolor的抑制率也大于90%。     

新型1H-吡唑-5-甲酰基氨基脲类化合物的合成及生物活性

采用活性亚结构拼接和生物合理设计的方法,将4-氯-1-甲基-3-乙基-5-吡唑甲酰肼与取代苯基异氰酸酯反应得到14个新的含氨基脲的吡唑类化合物。其结构经IR、1H NMR、质谱和元素分析确证。初步生物活性实验结果表明, 化合物1-( 4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基) -4-(2-甲基苯基)氨基脲( 4g) , 1-( 4-氯-3-乙基-1-甲基-1H-吡唑-5-甲酰基) -4-( 4-氯苯基)氨基脲( 4b)在500μg /mL 剂量下对小麦白粉病菌Bumeria graminis和粘虫Mythimna separata 的抑制率和致死率分别达到90%和100%。     

Herbicide pyrazolate causes cessation of carotenoids synthesis in early watergrass by inhibiting 4-hydroxyphenylpyruvate dioxygenase

In aqueous solution, the herbicide pyrazolate [4‐(2,4‐dichlorobenzoyl)‐1,3‐dimethyl‐5‐pyrazolyl p‐toluenesulfonate] is rapidly hydrolyzed to destosyl pyrazolate (DTP), 4‐(2,4‐dichlorobenzoyl)‐1,3‐dimethyl‐5‐hydroxypyrazole, which is an active form of the herbicide. The objective of this study was to examine the effect of pyrazolate and DTP on carotenoids synthesis in susceptible weed, early watergrass (Echinochloa oryzicola Vasing.). Furthermore, their in vitro effect on 4‐hydroxyphenylpyruvate dioxygenase (HPPD) was determined. Roots of the plants at the two‐leaf stage were soaked for 24 h into pyrazolate (5 × 10^–5 mol L^?1) or norflurazon (10^–6 mol L^?1) solution containing 0.5% volume of acetone. At the first sampling time (3 days after treatment: 3 DAT), the chlorophyll content in the third leaves of pyrazolate‐treated plants were not different compared with the untreated control, but it was decreased between 3 and 6 DAT. The declining pattern of β‐carotene in the third leaf of early watergrass was very similar to that of chlorophyll. Both herbicides induced greater accumulation of phytoene in the third leaves of early watergrass 3 DAT, and the levels were kept until 9 DAT. However, feeding of homogentisate reduced the phytoene accumulation only in pyrazolate‐treated plants, suggesting the site of action of the herbicide located in the pathway of plastoquinone synthesis. In a HPPD assay, DTP revealed to inhibit the enzyme with an IC₅₀ value of 13 nmol L^?1 and that of pyrazolate was 52 nmol L^?1. In the pyrazolate solution used in the assay, some of the herbicide possibly has been hydrolyzed to DTP. From the all results obtained, it is strongly suggested that pyrazolate inhibits carotenoids synthesis and causes bleaching on the developing leaves by the similar mechanism with norflurazon, but its action site is not phytoene desaturase and is HPPD.     

Benzpyrimoxan: Design,synthesis, and biological activity of a novel insecticide

Benzpyrimoxan (5-(1,3-dioxan-2-yl)-4-{[4-(trifluoromethyl)phenyl]methoxy}pyrimidine, NNI-1501) was discovered as a novel insecticide structurally characterized by a pyrimidine derivative substituted with 1,3-dioxanyl and 4-trifluoromethylbenzyloxy groups. The compound showed remarkable activity against nymphs of rice planthoppers, including strains resistant to existing insecticides. Furthermore, benzpyrimoxan had low adverse effects on pollinators and beneficial arthropods. Because of these features, benzpyrimoxan is expected to be a suitable part of an integrated pest management strategy. In this report, the history of the discovery to reach benzpyrimoxan and details of the structure–activity relationships are described.     

Design,synthesis and structure–activity relationships of novel ALS inhibitors

The paper describes the biophore models of sulfonylurea, imidazolinone, triazolopyrimidinesulfonamide and 5‐pyrimidyltriazolo‐3‐sulfonamides established by the Apex‐3D method. A series of N‐phenylsulfonyl‐N ′‐(thiadiazol‐2‐yl)oxamides and three types of triazolopyrimidinesulfonamide were synthesised and their herbicidal activities determined to assess the validity of the model. In general, the model gave useful leads to activity, although the actual level was not always predicted accurately. In only a few cases did compounds predicted as being active prove to be inactive in the bioassay, and compounds with little or no activity were clearly indicated. As a result of this work, the compound N,N ′‐[1‐(5,7‐dimethyl‐1,2,4‐triazolo[1,5‐a]pyrimidin‐2‐yl‐thio)butane‐2,3‐di‐imino]bis(2‐chlorobenzenesulfonamide) was selected as showing good activity against a range of species, and will be used as a lead for further development. © 2000 Society of Chemical Industry     

Design and biological activity of a novel fungicide,quinofumelin

Developed by Mitsui Chemicals Agro, Inc. (Tokyo, Japan), quinofumelin is a novel fungicide with a distinct chemical structure including 3-(isoquinolin-1-yl) quinoline, demonstrating fungicidal activity against a variety of fungi, including rice blast and gray mold. We screened our compound library to identify curative compounds for rice blast and evaluated the effect of fungicide-resistant strains of gray mold. Our research demonstrated that quinofumelin has curative effects against rice blast and is not cross-resistant to existing fungicides. Accordingly, the use of quinofumelin can be considered a novel approach for disease control in agricultural production. In this report, the discovery of quinofumelin from the initial compound is described in detail.