A novel synthesis and herbicidal activity of fluorine-containing pyrazolo[3,4-d]pyrimidin-4-one derivatives

The 6-(4-alkoxycarbonylalkoxy)phenoxy-3-alkylthio-5-(fluoro-substituted)phenyl-1-phenylpyrazolo[3,4-d]pyrimidin-4-ones 6 have been successfully synthesized via a tandem aza-Wittig and annulation reactions of the corresponding iminophosphorances 4, aromatic isocyanate, and substituted phenols 2 in 59-69% isolated yields using actonitrile as solvent. These novel compounds 6 could be oxidized to sulfones 7 by hydrogen peroxide in satisfactory yields (57-93%). Their structures were clearly verified by spectroscopic data (IR, ¹H NMR, ¹³C NMR, MS, Elemental analysis or X-ray diffraction crystallography). The results of preliminary bioassay indicated that these compounds possess herbicidal activity against the root of rape and barnyard grass.     

Peroxydisulfate-assisted sonocatalytic degradation of metribuzin by La-doped ZnFe layered double hydroxide

Metribuzin is an herbicide that easily contaminates ground and surface water. Herein, La-doped ZnFe layered double hydroxide (LDH) was synthesized for the first time and used for the degradation of metribuzin via ultrasonic (US) assisted peroxydisulfate (PDS) activation. The synthesized LDH had a lamellar structure, an average thickness of 26 nm, and showed mesoporous characteristics, including specific surface area 110.93 m² g⁻¹, pore volume 0.27 cm³ g⁻¹, and pore diameter 9.67 nm. The degradation efficiency of the US/La-doped ZnFe LDH/PDS process (79.1 %) was much greater than those of the sole processes, and the synergy factor was calculated as 3.73. The impact of the reactive species on the sonocatalytic process was evaluated using different scavengers. After four consecutive cycles, 10.8 % loss occurred in the sonocatalytic activity of the La-doped LDH. Moreover, the efficiency of the US/La-doped LDH/PDS process was studied with respect to the degradation of metribuzin in a wastewater matrix. According to GC–MS analysis, six by-products were detected during the degradation of metribuzin. Our results indicate that the US/La-doped ZnFe LDH/PDS process has great potential for efficient degradation of metribuzin-contaminated water and wastewater.     

小麦ACCase CT功能域基因在大肠杆菌中的表达及与除草剂的相互作用

以中国春小麦幼苗为材料,克隆构建了小麦质体乙酰辅酶A羧化酶(ACCase)的羧基转移酶(CT)重组质粒( RCP18-5),并实现了重组质粒在大肠杆菌中的可溶性高表达.对重组蛋白的性质研究表明,该蛋白具有较强的疏水性,稳定性不高.为改善这种状况,对CT功能域基因进行了截短和延长,同样于大肠杆菌中进行表达.结果表明,仅长...     

四种新芳氧羧酸类除草剂的拉曼光谱研究

对除草剂的研究是提高我国粮食作物产量的一种有效途径,我国的现状要求我们加大对除草剂研究的力度。采用共聚焦拉曼光谱仪对四种新合成的芳氧羧酸类除草剂进行了研究,得到了拉曼光谱信息,并对谱峰进行了归属,得到了此类化合物的特征谱峰的位置;此外,还测试了这四种除草剂的除草活性,发现I_2,I_3的除草活性最好,I_4次之,I_1最差,并用拉曼谱峰所给出的信息对除草活性的差异进行了解释。认为在所研究的这类除草剂中,芳氧乙酸类化合物的生成有利于增加除草活性。     

Gas-chromatographic determination of pesticide residues after clean-up by gel-permeation chromatography and mini-silica gel-column chromatography

Zusammenfassung Es wird eine Methode für die gaschromatographische Bestimmung von 11 herbiciden Phenoxyalkancarbonsäuren sowie deren Ester und Konjugate in Pflanzenmaterial beschrieben. Nach alkalischer Hydrolyse werden die Säuren aus dem angesäuerten Hydrolysat durch Aceton/Wasser/Dichlormethan-Verteilung extrahiert. Der Extrakt wird über Gel-Chromatographie an Bio Beads S-X3 und eine Säure/Base-Ausschüttelung gereinigt. Die Säuren werden mit Methanol/Schwefelsäure verestert. Die gaschromatographische Bestimmung erfolgt massenfragmentographisch als Methylester. 2,4-D, 2,4-DB, Dichlorprop, Diclofop-methyl, Fenoprop und 2,4,5-T können gas-chromatographisch auch mit dem Elektroneneinfangdetektor bestimmt werden, wenn die Methylesterlösungen an einer Mini-Kieselgel-Säule nachgereinigt werden.

---

Gas-chromatographic determination of pesticide residues after clean-up by gel-permeation chromatography and mini-silica gel-column chromatography4. Communication. gas-chromatographic determination of 11 herbicidal phenoxyalkyl acids and their esters

Summary A method is described for the gas-chromatographic determination of 11 herbicidal phenoxyalkyl acids, their esters and conjugates in plant material. The method includes alkaline hydrolysis, extraction of the acids by aceton/water/dichloromethane partition, gel permeation Chromatography, acid/base distribution, methylation with methanol/sulphuric acid and detection by gas-chromatography/mass fragmentography. 2,4-D, 2,4-DB, dichlorprop, diclofop methyl, fenoprop and 2,4,5-T can likewise be detected by electron-capture gas-chromatography after additional clean-up of the methyl ester solutions by minisilica gel-column Chromatography.

1. Mitt.: Organochlor-Pflanzenbehandlungsmittel in Tabak und Tabakerzeugnissen. Beitr. Tabakforsch. Int. 10, 73–79 (1979). 2. Mitt.: Bestimmung der Fungizide Bitertanol, Fluotrimazol, Fuberidazol, Imazalil, Rabenzazole, Triadimefon und Triadimenol in Pflanzen und Boden. Pflanzenschutz-Nachrichten Bayer 33, 61–85 (1980). 3. Mitt.: Methode zur Aufarbeitung von Lebensmitteln und Futtermitteln pflanzlicher und tierischer Herkunft für die Multirückstandsbestimmung lipoid- und wasserlöslicher Pflanzenbehandlungsmittel. Fresenius Z. Anal. Chem. 301, 300–307 (1980)     

Biomimetic oxidation of metribuzin with hydrogen peroxide catalyzed by 5,10,15,20-tetraarylporphyrinatoiron(III) chlorides

The biomimetic oxidation of metribuzin, a pre- and post-emergence herbicide with hydrogen peroxide catalyzed by 5,10,15,20-tetraarylporphyrinatoiron(III) chlorides [TAPFe(III)Cl], has been studied yielding 6-t-butyl-3-methylthio-1,2,4-triazine-5(4H)-one, 4-amino-6-t-butyl-3,5(2H,4H)-dione and 6-t-butyl-1,2,4-triazin-3,5(2H,4H)-dione under various reaction conditions.     

聚乙烯醇固定化的微球菌AD3对除草剂阿特拉津的生物降解

从农药厂的工业废水和污泥的混合物中分离到高效降解除草剂阿特拉津的藤黄微球菌(Micrococcusluteus)AD3菌株。以聚乙烯醇(PVA)为包埋材料进行AD3菌株的固定化,对影响固定化细胞降解阿特拉津的因素(如阿特拉津浓度、温度、pH)和操作稳定性进行了研究。结果表明,在最适条件下(30℃、pH7.2、阿特拉津浓度500mg/L)固定化细胞的阿特拉津降解速度明显高于游离细胞。固定化细胞在低温、低pH和高阿特拉津浓度条件下的阿特拉津降解率,以及贮存和操作稳定性,也明显好于游离细胞。固定化细胞在15℃、pH7.2、阿特拉津浓度为500mg/L的条件下培养72h以后,阿特拉津降解率为90%,在相同条件下游离细胞的降解率仅为35%。固定化细胞在pH5.0、30℃、阿特拉津浓度为500mg/L的条件下培养72h以后,降解率为96%,在相同条件下游离细胞的降解率仅为40%。固定化细胞能够快速降解1000mg/L的阿特拉津,而游离细胞则不能。稳定性实验表明,固定化细胞重复使用30次以后其降解活力没有明显降低。     

交联CMC控制释放除草剂的研究

本文报道以交联羧甲基纤维素囊化除草剂2，4，5－T、2，4－D和麦草畏二甲基胺盐所制成的控制释放体系的释放性能。研究了交联方法。制品形态、CMC取代度、交联剂用量和载药量等制备工艺条件对控释性能的影响。结果表明，以低取代度的CMC，经较大量甲醛交联制得的粒状制品，具有较好的控制释放性能。     

Convenient Synthesis of Two Novel Oxazolidines and Primary Research on their Biological Activities

Herbicide safeners selectively protect crop plants from herbicide damage without reducing activity in target weed species. These compounds have generated consider- able commercial interest and research activity since the phenomenon of herbicide safening w…     

The Photocatalytic Degradation of Imazapyr

Summary. The degradation of imazapyr, an imidazolinone herbicide, in aqueous solution has been investigated with TiO₂ slurry as photocatalyst at 30°C under UV radiation. The depletion of imazapyr concentration in an aqueous suspension followed 1^st order kinetic behavior. The influence of pH and the charge densities of imazapyr geometries were calculated at the semi-empirical AM1 level, and the effect of temperature was investigated. The addition of electron acceptors such as potassium persulfate and hydrogen peroxide showed that the rate constant doubled at least. At higher persulfate concentrations the herbicide degradation was more efficient in direct photolysis than TiO₂-photocatalysis. The degradation rate constant increased by 38% upon variation of the temperature between 20.0 and 50.0°C and displayed non-Arrhenius behavior.