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苦参(SophoraflavescensAit)为豆科槐属灌木,分布广泛,是我国历史悠久的传统药物之一,主要功效清热、杀虫、利尿、祛湿[1]。苦参在农业上的应用,近几年引起人们的重视,有1.1%苦参碱醇溶液等几个产品获得登记。但多数研究只是停留在苦参的粗提物直接用于病虫害防治上,对苦参的生物活性与其成分的联系研究甚少。本文以生物活性追踪试验为指导,从苦参提取物中分离到2个主要杀虫抑菌活性化合物,参考文献报道的波谱数据,确定其结构分别为苦参酮(Kurarinone)(I)和槐属二氢黄酮G(SophoraflavanoneG)(II)。I R=OCH3 II R=H1 结果与讨… 相似文献
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为了发现具有生物活性的新化合物,以溴代吡咯腈为先导化合物,通过亲核取代等反应合成了一系列新型2-(溴代吡咯腈-1-基)乙酸衍生物(5a~5m, 6a~6o),其结构均经核磁共振氢谱(1H NMR)、碳谱(13C NMR)和高分辨质谱(HRMS)确证。杀菌活性测定结果显示:化合物2、3和5m对水稻稻瘟病菌Magnaporthe oryzae均表现出良好的杀菌活性,其EC50值分别为0.0532、0.0470和0.0174 mmol/L,优于对照药剂咯菌腈(0.0914 mmol/L),但不及对照药剂嘧菌酯(0.0001 mmol/L);化合物5m表现出一定的杀菌广谱性,其对水稻纹枯病菌Rhizoctonia solani和小麦根腐病菌Bipolaris sorokiniana的EC50值分别为0.0218和0.0420 mmol/L,但均不及对照药剂咯菌腈(EC50值分别为0.0002和0.0010 mmol/L)。杀虫、杀螨活性测定结果显示,在0.2 mmol/L浓度下,目标化... 相似文献
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This paper reports the investigation of the insecticidal and fungicidal activity of dunnione, a natural product obtained inadvertently as a by-product of a synthesis programme. Dunnione exhibits no insecticidal activity but has an unusually broad spectrum of antifungal activity. In vitro and in vivo (preventative) activities were comparable to those of several long-established fungicides (eg carbendazim). However, in whole-plant assays, its eradicant activity was unexpectedly low, probably due to poor dose-transfer from leaf surface to fungus. The level of residual activity appears to be influenced by the formulation. Finally, its potential as a lead structure was assessed, and several analogues synthesised which exhibited high activity in the in vitro assays. Mode-of-action studies revealed that dunnione exerts its action primarily through initiation of redox cycling. This contrasts to the activity of BTG 505, the biochemical/chemical precursor, which does not initiate redox cycling but instead exhibits both insecticidal and fungicidal activity by inhibiting mitochondrial Complex III. 相似文献
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为了发现农药活性的新化合物,以溴代吡咯腈为原料,通过亲核取代、肼解和成环等反应,设计合成了一系列N-((5-烷硫基-1,3,4-噁二唑)-2-基)甲基溴代吡咯腈目标化合物( 5a ~ 5t ),所有化合物的结构均得到核磁共振氢谱和高分辨质谱确证。杀菌活性测定结果显示:在浓度为0.20 mmol/L时,大部分目标化合物具有一定的抑菌活性,其中化合物 5h 对水稻稻瘟病菌Magnaporthe oryzae的抑制率为60.07%,优于对照药剂咯菌腈(58.21%)。杀虫与杀螨活性测定结果显示:在浓度为0.20 mmol/L时,大部分目标化合物对斜纹夜蛾Spodoptera litura和朱砂叶螨Tetranychus cinnabarinus雌成螨具有一定的杀虫和杀螨活性,但均低于对照药剂虫螨腈(100%)。杀线虫生物测定结果显示:在浓度为0.20 mmol/L时,大部分目标化合物表现出优异的杀线虫活性,其中化合物 5k 、 5r 和 5s 对秀丽隐杆线虫Caenorhabditis elegans的LC50值分别为0.0918、0.0733和0.0810 mmol/L,优于对照药剂噻唑膦(0.2798 mmol/L)。本研究所合成的目标化合物具有一定的杀菌、杀虫、杀螨和杀线虫活性,可为溴代吡咯腈衍生物的设计和合成提供参考。 相似文献
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Seventeen new alkyl (or phenacyl) phenyl (dichloromethyl)phosphonates were synthesised; seven of these showed poor fungicidal activity when tested in vitro against Pyricularia oryzae but some possessed high insecticidal activity against Culex fatigans and Drosophila melanogaster. 相似文献
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Rabea EI Badawy ME Rogge TM Stevens CV Höfte M Steurbaut W Smagghe G 《Pest management science》2005,61(10):951-960
Chitosan, the N-deacetylated derivative of chitin, is a potential biopolysaccharide owing to its specific structure and properties. In this paper, we report on the synthesis of 24 new chitosan derivatives, N-alkyl chitosans (NAC) and N-benzyl chitosans (NBC), that are soluble in dilute aqueous acetic acid. The different derivatives were synthesized by reductive amination and analyzed by 1H NMR spectroscopy. A high degree of substitution (DS) was obtained with N-(butyl)chitosan (DS 0.36) at a 1:1 mole ratio for NAC derivatives and N-(2,4-dichlorobenzyl)chitosan (DS 0.52) for NBC derivatives. Their insecticidal and fungicidal activities were tested against larvae of the cotton leafworm Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae), the grey mould Botrytis cinerea Pers (Leotiales: Sclerotiniaceae) and the rice leaf blast Pyricularia grisea Cavara (Teleomorph: Magnaporthe grisea (Hebert) Barr). The oral feeding bioassay indicated that all the derivatives had significant insecticidal activity at 5 g kg(-1) in artificial diet. The most active was N-(2-chloro-6-fluorobenzyl)chitosan, which caused 100% mortality at 0.625 g kg(-1), with an estimated LC50 of 0.32 g kg(-1). Treated larvae ceased feeding after 2-3 days; the mechanism of action remains unknown. In a radial hyphal growth bioassay with both plant pathogens, all derivatives showed a higher fungicidal action than chitosan. N-Dodecylchitosan, N-(p-isopropylbenzyl)chitosan and N-(2,6-dichlorobenzyl)chitosan were the most active against B cinerea, with EC50 values of 0.57, 0.57 and 0.52 g litre(-1), respectively. Against P grisea, N-(m-nitrobenzyl)chitosan was the most active, with 77% inhibition at 5 g litre(-1). The effect of different substitutions is discussed in relation to insecticidal and fungicidal activity. 相似文献
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井冈羟胺A (validoxylamine A) 作为重要的生物农药中间体具有抑菌和杀虫活性。为开发新型绿色农药,以井冈羟胺A作为先导化合物,通过脂肪酶催化酯化反应,合成了9个未见文献报道的井冈羟胺A酯类衍生物,通过核磁共振氢谱、碳谱以及高分辨质谱对其结构进行了表征。生物活性测定结果表明:大部分目标化合物对立枯丝核菌Rhizoctonia solani具有抑制活性,其中化合物 Ⅰ 的抑制效果最好,EC50值为13.03 μmol/L;化合物 Ⅶ 在500 mg/L下对豆蚜Aphis craccivora的致死率为64.60%。该类衍生物具有一定的抑菌、杀虫活性,有进一步研究的价值。 相似文献
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为探索新的农药先导化合物,经取代苯基呋喃甲酰氯与5-肼基-3(2H)哒嗪酮反应,得到15个未见文献报道的含呋喃环3(2H)哒嗪酮类化合物,其结构均通过了红外光谱、核磁共振氢谱和元素分析确认。初步生物活性测定结果表明,目标化合物具有良好的杀菌活性,但杀虫活性较弱。其中化合物3k在50 mg/L时对灰霉病菌的抑制率为86.29%±1.51%,与对照药剂腐霉利相当。初步的构效关系研究结果显示,苯环上取代基的种类和位置对杀菌活性有重要影响。 相似文献
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以1,2,4-三唑、2-氯-2,4-二氟苯乙酮和哌嗪为原料,通过活性亚结构拼接合成了一个系列20个新型三唑哌嗪类衍生物 7a ~ 7t ,其结构均经过了1H NMR、13C NMR和高分辨质谱确证。分别采用菌丝生长速率法和触杀法测定了目标化合物的杀菌活性和杀虫活性。杀菌活性测定结果显示:大部分化合物对小麦赤霉病菌、水稻纹枯病菌和水稻稻瘟病菌具有良好的抑制作用,在200 μmol/L下,化合物 7n 、 7r 和 7s 对小麦赤霉病菌的抑制率分别为60.19%、62.27%和50.00%,与对照药剂三唑酮抑菌效果相当;化合物 7r 对水稻纹枯病菌的EC50值为49.49 μmol/L。杀虫活性测定结果显示,在100 mg/L时,化合物 7o 对斜纹夜蛾幼虫的致死率为40.00%,略低于对照药剂氰氟虫腙 (46.67%)。本研究所合成的新化合物兼具杀菌和杀虫活性,可为新型三唑哌嗪类衍生物的生物活性研究提供参考。 相似文献
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In the course of screening for naturally occurring insecticides from plants from the northwestern part of China, a petroleum ether extract of Juniperus sabina L was found to show insecticidal activity against fifth-instar larvae of Pieris rapae L. From the extract, an insecticidal compound was isolated by bioassay-guided fractionation. The compound was identified as deoxypodophyllotoxin (1) by comparison of its spectroscopic characteristics with literature data. In bioassays, 1 showed antifeedant activity against fifth-instar larvae of P rapae at 0.05-1.00 g litre(-1) and its AFC50 (concentration for 50% antifeedant activity) values at 12 and 48h were 0.170 and 0.060 g litre(-1), respectively. In that concentration range, all treated insects died within 48 h after treatment and compound 1 showed delayed insecticidal activity. At 0.015-0.100 g litre(-1), 1 showed insecticidal activity, with an LC50 of 0.020 g litre(-1). The related compound deoxypicropodophyllotoxin (2), however, showed lower antifeedant and insecticidal activities than 1 in bioassay. This indicated that the trans-lactone ring is an important moiety for enhancing activity in these compounds. Comparison of the insecticidal activities of 1 and another related compound, podophyllotoxin (3), suggested that varying the substituent at C-4 is an exciting possibility for synthesizing more potent analogues. 相似文献
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为了发现和开发新的杀菌化合物,以嘧菌酯为先导,通过活性亚结构拼接等手段,设计并合成了22个新化合物,通过核磁共振氢谱、碳谱及高分辨质谱等手段对其结构进行了表征。生物活性测试结果表明,部分化合物对黄瓜白粉病菌表现出较好的杀菌活性,其中化合物 7b 在50 mg/L下对黄瓜白粉病菌的抑制率为85%。田间试验结果显示,在有效成分281.25 g/hm2剂量下,化合物 7b 对黄瓜白粉病的防治效果与商品化品种推荐使用剂量时嘧菌酯 (有效成分281.25 g/hm2) 和乙嘧酚 (有效成分300.00 g/hm2) 的防治效果相当。 相似文献
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