植物源他感除草剂的研究进展

杂草对农作物的危害已超过其他有害生物。开发高效、低毒与环境相容性好的除草剂势在必行。植物之间产生的他感物质为开发除草剂提供有益的启示。本文综述了自然界中存在的他感现象及其有效成分、释放机制和开发前景。     

盐酸美普他酚有关物质的合成

以1-甲基-3-(3-羰基环己基-1-烯)-1H-六氢氮杂卓-2-酮为原料,经过脱氢芳构化、乙基化、对接、氢化铝锂还原制备了盐酸美普他酚有关物质,中间体及目标化合物经过1HNMR、MS表征。     

HPLC法测定地氯雷他定有关物质

建立了高效液相色谱法测定地氯雷他定有关物质的分析方法。采用Thermo Hypersil BDS C_(18)(4. 6×250 mm,5μm)色谱柱,以乙腈-甲醇-磷酸盐缓冲液(10∶10∶80)为流动相A,以乙腈-四氢呋喃-磷酸盐缓冲液(45∶5∶50)为流动相B,梯度洗脱;流速1. 0 mL/min检测波长为280 nm,柱温30℃,进样量为20μL。地氯雷他定与各杂质峰分离度良好。该方法简单、快速、可靠、高效,本方法能有效的测定地氯雷他定的有关物质。     

除草剂老品种的市场开发新机遇——2，4-滴评述

2，4-滴(2，4-D)是世界上第一个除草剂，由Amchem公司(今先正达公司)于1942年发现并合成，1945年后多家公司开发生产，于1946年开始使用。自发现至今，已经有60多年的发展历史，可以说是一个非常古老的除草剂。60年中它的销售长盛不衰，使用一直广泛。1998年销售额2．4亿美     

一株链霉菌化感活性物质提取研究性实验设计

链霉菌属是绝大多数已知抗生素和一些重要化感活性物质的产生菌,而化感活性物质的提取方法是研究化感作用的重要步骤,以一株链霉菌化感活性物质提取实验项目设计为学生的研究性实验,学生通过查阅相关文献,设计实验方案,优选提取方法,使溶剂消耗及环境污染显著降低。该实验有助于增强学生的环保意识,提高学生实验技能及科技创新能力。     

倍他司汀有关物质的合成

倍他司汀是一种新型组胺H1受体的弱激动剂,具有扩张毛细血管,舒张前毛细血管括约肌,增加前毛细血管微循环血流量的作用.临床主要用于治疗美尼尔综合征(内耳眩晕症),血管性头痛及脑动脉硬化,也可用于治疗急性缺血性脑血管疾病等.有关物质研究是药品质量研究的关键,其含量是反映药品纯度的直接指标.本文报道了5个倍他司汀有关物质的合...     

化感物质抑制藻类过度繁殖的机理及效能研究进展

近年来,蓝藻水华的频发及其藻毒素次生等代谢产物的污染不断危害着水生生态环境和社会安全,植物分泌的化感物质被证实对水华藻种具有一定控制作用,能通过拮抗作用抑制藻类的过度繁殖。文中针对化感物质对水华藻种的抑制作用,在总结化感物质抑藻研究现状的基础上,重点阐明化感物质的典型种类以及其对水华藻种的作用机理及效能,同时结合实际水体中藻类控制需求,分析了现有化感物质抑藻研究中存在的不足,并对后续研究趋势进行了展望。     

厄他培南钠中间体有关物质的合成及其结构确证

介绍了厄他培南钠中间体3个有关物质的合成方法,并对其进行了HRMS和NMR (~1H NMR、COSY、~(13)C NMR、DEPT135°、HSQC、HMBC和D_2O)确证以及碳氢信号的归属,为其质量研究提供了参考。     

新型除草剂碘甲磺隆钠盐

碘甲磺隆钠盐属磺酰脲类除草剂,通过抑制乙酰乳酸合成酶而起作用,主要用于小麦田,苗后早期防除黑麦草、野燕麦、梯牧草和多种阔叶杂草。介绍了碘甲磺隆钠盐的合成方法。     

水田除草剂环苯草酮

概述了水田除草剂环苯草酮的化学名称、理化性质、毒性、作用机理、专利、合成方法与应用等.     

世界除草剂市场发展述评

世界除草剂市场发展很快，１９９４年除草剂销售额达１３９亿美元，占农药市场的４６．７％；诸作物中，玉米等８种使用除草剂最多；北美除草剂用量最大，远东用量正在迅速增长；三嗪类仍占第１位，但磺酰脲类等正在兴起，不久将取而代之。     

新型除草剂氯氟吡氧乙酸十二酯的含量测定

研究高效液相色谱测定氯氟吡氧乙酸十二酯含量的方法.选用C18液相色谱柱,以乙腈为流动相,在UV 210 nm下对样品进行定量分析.测定的标准偏差为1.199,变异系数为0.33%,回收率在89.9%～97.7%之间,线性相关系数为0.995 8.     

新型除草剂茚嗪氟草胺的合成综述

茚嗪氟草胺是一种新型的烷基嗪类除草剂.综述了近年来茚嗪氟草胺的合成方法,推荐了茚嗪氟草胺合成的最优路线.     

氟噻草胺的合成

本文介绍氟噻草胺合成工艺,以水合肼、三氟乙酸为原料合成2-甲砜基-5-三氟甲基-1,3,4-噻二唑;以对氟硝基苯、丙酮经过催化加氢、酰化、醇解合成N-(4-氟苯基[(\))0(-)]N-异丙基-2-羟甲基乙酰胺;及氟噻草胺的制备。     

除草剂氟丙嘧草酯的合成新工艺

研究了除草剂氟丙嘧草酯的合成方法。以2-氯-5-硝基苯甲酸为原料,经过酯化、还原、异氰酸化、环合4步反应制得氟丙嘧草酯。在适宜的条件下,制得的氟丙嘧草酯的质量分数为99.5%,总收率为55.5%。     

Allelochemical Potential of Callicarpa acuminata

The allelochemical potential of Callicarpa acuminata (Verbenaceae) was investigated by using a biodirected fractionation study as part of a long-term project to search for bioactive compounds among the rich biodiversity of plant communities in the Ecological Reserve El Eden, Quintana Roo, Mexico. Aqueous leachate, chloroform-methanol extract, and chromatographic fractions of the leaves of C. acuminata inhibited the root growth of test plants (23-70%). Some of these treatments caused a moderate inhibition of the radial growth of two phytopathogenic fungi, Helminthosporium longirostratum and Alternaria solani (18-31%). The chloroform-methanol (1:1) extract prepared from the leaves rendered five compounds: isopimaric acid (1), a mixture of two diterpenols [sandaracopimaradien-19-ol (3) and akhdarenol (4)], alpha-amyrin (5), and the flavone salvigenin (6)]. The phytotoxicity exhibited by several fractions and the full extract almost disappeared when pure compounds were evaluated on the test plants, suggesting a synergistic or additive effect. Compounds (4), (5), and the semisynthetic derivative isopimaric acid methyl ether (2) had antifeedant effects on Leptinotarsa decemlineata. Compound 5 was most toxic to this insect, followed by (2), (4), and (6) with moderate to low toxicity. No correlation was found between antifeedant and toxic effects on this insect, suggesting that different modes of action were involved. All the test compounds were cytotoxic to insect Sf9 cells while (6), (4), and (1) also affected mammalian Chinese Hamster Ovary (CHO) cells. Compound 5 showed the strongest selectivity against insect cells. This study contributes to the knowledge of the defensive chemistry and added value of C. acuminata.     

脲嘧啶类除草剂Tiafenacil的合成新方法

介绍了一种由中间体3-(2-氯丙酰基氨基)丙酸甲酯和3-(4-氯-2-氟-5-巯苯基)-1-甲基-6-(三氟甲基)嘧啶-2,4(1H,3H)-二酮合成Tiafenacil的新方法。     

Allelochemical Potential of Metopium brownei

Metopium brownei is a tree that grows in coastal tropical forests along the Gulf of Mexico and in the Yucatan Peninsula. This medicinal species produces a strongly irritant exudate, and sometimes forms pure populations favored by fire. The bioactivity of the aqueous leachates, organic extracts (leaves, bark, and wood), and mixtures of urushiols and flavonoids from M. brownei were evaluated on the growth of two plants: Amaranthus hypochondriacus and Echinochloa crusgalli, and four phytopathogenic fungi: Fusarium oxysporum, Helminthosporium sp., Alternaria sp., and Pythium sp. Alkylcatechols (urushiols) were isolated from an acetone extract of the bark. Dihydroquercetin and eriodictyol were isolated from the chloroform–methanol extract of the wood. In addition, masticadienoic acid was isolated from the leaves. The aqueous leachates, organic extracts, and the mixtures of flavonoids and urushiols were inhibitory to the growth of test plants and phytopathogenic fungi. The allelochemical role of the bioactive compounds from M. brownei is discussed in relation with other results reported in some studies on Anacardiaceae family and M. brownei.