Effects of sterol biosynthesis-inhibiting fungicides and plant growth regulators on the sterol composition of barley plants

A number of sterol biosynthesis-inhibiting (SBI) fungicides and plant growth regulator analogs were applied as root drenches to barley seedlings and their effect on the total sterol composition of the roots and shoots was measured by gas-liquid chromatography. Prochloraz was found to be inactive in this system, probably because of poor uptake, while the other compounds could be divided into two groups according to their mode of action as assessed by sterol profiling. The morpholines tridemorph and fenpropimorph inhibited the enzyme cycloeucalenol—obtusifoliol isomerase whereas triadimenol, nuarimol, paclobutrazol, and triapenthenol (RSW 0411) inhibited the enzyme responsible for the removal of the C-14 methyl group. Effects of individual diastereo-isomers and enantiomers of some compounds on sterol profiles were compared with their known fungicidal and anti-gibberellin properties. Shoot growth was reduced by all the compounds tested, paclobutrazol, nuarimol, and triapenthenol being the most effective. As well as inducing accumulation of abnormal sterols, SBI fungicide treatment changed the ratio of campesterol to stigmasterol and sitosterol. It is hypothesized that this may reflect changes in membrane architecture and may offer an explanation for the increased frost hardiness sometimes observed with SBI fungicide-treated plants.     

具有农业生物活性壳寡糖的研究进展

壳寡糖是一类由N-乙酰氨基葡萄糖或氨基葡萄糖通过β-(1,4)-糖苷键连接起来的低聚合度水溶性的糖类,在食品、医药、化妆品等方面具有广泛用途。主要评述了壳寡糖在植物生长调节(诱导抗性)、杀菌作用以及杀虫活性方面的应用,表明壳寡糖是一种对环境友好的、良好的生物源农药。     

新型植物生长调节剂多效唑钾盐在双季超级杂交稻上的应用效果

选用超级杂交早稻淦鑫203和晚稻五丰优T025,于秧苗期喷施新型植物生长调节剂多效唑钾盐,并以多效唑及清水为对照,考查了株高、秧苗素质、产量及其构成因素等,结果表明:早、晚稻喷施多效唑钾盐和多效唑处理株高较喷施清水处理分别降低41.71%、47.32%和28.41%、26.97%,单株产量分别增加34.83%、15.69%和37.16%、5.44%;早、晚稻喷施多效唑钾盐秧苗素质及产量构成指标也存在较强的优势;新型植物生长调节剂多效唑钾盐对水稻具有较好的控高增产效果。     

不同化学及营养调控措施配合对旱地冬小麦生长及产量的影响

黄土高原南部旱作区,田间试验不同化学及营养调控措施对小麦生长发育及产量的影响。结果表明,施氮可以明显促进小麦分蘖,使用植物生长调节剂及其与微量元素(MnSO4)配合对小麦分蘖有促进,其中以多效唑及其与MnSO4配合处理较为突出;多效唑处理降低了小麦株高。植物生长调节剂及其与MnSO4配合增加了小麦叶面积和叶片的SPAD值,其中多效唑 MnSO4 甜菜碱处理的叶面积及SPAD值的增加尤为突出。采用多效唑、MnSO4和甜菜碱以及多效唑和MnSO4配合显著提高了小麦产量,较清水对照产量分别提高了1 014.7kg/hm2和640.5 kg/hm2。说明不同的化学及营养调控措施可以有效地调节小麦生长,提高作物产量。     

含苯乙酮结构片段的吩嗪-1-羧酸酯类衍生物的合成及生物活性

为了提高吩嗪-1-羧酸 (申嗪霉素) 的生物活性,以吩嗪-1-羧酸和不同取代的苯乙酮为原料,通过溴化反应和亲核取代反应,合成了22个未见文献报道的含苯乙酮结构片段的吩嗪-1-羧酸酯类化合物 3a ～ 3c 和 6a ～ 6s ,其结构均得到核磁共振氢谱(1H NMR)、碳谱(13C NMR)和高分辨质谱确证。分别采用菌丝生长速率法和琼脂保湿浸叶法测定了目标化合物对6种植物病原菌的杀菌活性和对朱砂叶螨雌成螨的杀螨活性。杀菌活性测定结果表明:在0.2 mmol/L下大部分目标化合物对水稻纹枯病菌Rhizoctonia solani具有一定的抑制作用,其中 6b 和 6e 的抑制率分别为56.05%和65.37%,低于对照药剂吩嗪-1-羧酸 (86.83%)。杀螨活性测定结果表明:药后24 h,大部分目标化合物对朱砂叶螨Tetranychus cinnabarinus雌成螨具有良好的杀螨活性,在1 mmol/L下化合物 6k 和 6m 的校正死亡率分别为87.88%和90.82%,进一步测得其相应的LC₅₀值分别为0.25 和0.19 mmol/L。本研究所合成的新化合物不仅具有一定的杀菌活性,还具有较好的杀螨活性,这为吩嗪-1-羧酸的进一步结构改造提供了新思路。     

Paclobutrazol and other plant growth-retarding chemicals increase resistance of melon seedlings to fusarium wilt

Studies were made of plant growth retardation and effects on resistance of melon to fusarium wilt by soil application of paclobutrazol, other ergosterol biosynthesis inhibitors, the fungicide benomyl and the herbicide dinitramine. Paclobutrazol and ancymidol delayed the onset of wilting and were the most effective in reducing wilt incidence. A relationship between effectiveness in retarding seedling elongation and increasing resistance to fusarium wilt was observed. No chemical had a significant effect on pathogen population level in the plant, as determined by stem colonization and direct assessment tests in seedlings grown in soil treated with the chemicals. Excluding benomyl, and to a lesser extent dinitramine, leaf and stem extracts had no inhibitory effect on conidial germination. Gibberellins GA₄₊₇, when applied to seedlings inoculated after germination in paclobutrazol-treated soil, nullified growth retardation and increased disease incidence. We suggest that disease incidence reduction by paclobutrazol is due to an effect on plant metabolic processes and not to direct fungitoxicity of the compound.     

草酸二丙酮胺-铜配合物的合成、结构表征及抑菌活性

报道了新化合物——草酸二丙酮胺-铜配合物的合成、结构表征及抑菌活性。目标化合物由二丙酮胺草酸盐与氯化铜在去离子水中反应制得,在乙醇溶液中获得单晶,经元素分析、红外光谱以及X-射线单晶衍射技术确定了其结构。采用抑制孢子萌发法测定了其对6种农业病原真菌的离体抑制活性。结果表明:当配合物中草酸、铜与二丙酮胺的物质的量之比为2∶ 1∶ 2时,其对6种供试病原真菌均表现出强烈的抑菌活性,毒力与对照药剂80%的代森锌可湿性粉剂相当。     

4-(吩嗪-1-酰氧基)肉桂酸酯和N-吩嗪-1-甲酰基-N'-肉桂酰基乙二胺的合成及生物活性

以不同取代的肉桂酸为原料,通过酯化反应和酰基的亲核取代反应对天然产物吩嗪-1-羧酸(申嗪霉素)进行了结构修饰,合成了2个系列含肉桂酸结构片段的吩嗪-1-羧酸酯类衍生物5a～～5f和吩嗪-1-甲酰胺类衍生物10a～～10r,所有衍生物的结构均得到核磁共振氢谱(1H NMR)、碳谱(13C NMR)和高分辨质谱确证.分别采...     

苦皮藤假种皮中的杀菌活性成分研究

用 5种溶剂对苦皮藤假种皮进行了系统提取 ,在灵敏的活性追踪指导下 ,从25%乙醇提取物中分离、鉴定了 3个具有杀菌活性的化合物 :麝香草酚、多羟基二氢沉香呋喃和间苯二酚 ,它们抑制玉米小斑病菌 Bip olaris maydis孢子萌发的 EC50 分别为 22 .27、53.32、169.29mg/L。其中麝香草酚为首次在卫矛科植物中分离得到 ,多羟基二氢沉香呋喃为首次在苦皮藤中分离得到。     

Rationally Designed Guanidine and Amidine Fungicides

A previous investigation established that compounds containing a guanidinium or amidinium grouping are effective inhibitors of sterol Δ⁸–Δ⁷ isomerase and/or Δ¹⁴ reductase activity in plant pathogenic fungi. A binding model for known fungicidal inhibitors of this enzyme has now been used to rationally design further guanidinium or amidinium inhibitors. Three novel classes of chemistry were investigated. The results of biochemical testing against ergosterol biosynthesis in Ustilago maydis (DC) Corda and of in-vivo testing for fungicidal activity against Erysiphe graminis DC f. sp. hordei Marchal (powdery mildew of barley), do much to support the binding model, and compounds with significant fungicidal activity have been found. © 1997 SCI.     

Comparison of root- and shoot-acting growth retardants on a grass/clover sward

The effects of six grass growth retardants, maleic hydrazide (±2,4-D), mefluidide, paclobutrazol, EL500 and a mixture of mefluidide with paclobutrazol on a grass/clover sward were compared over a 3-year period. Maleic hydrazide, which is the most commonly used retardant, gave poor levels of growth control except when used with 2,4-D. Greatest growth suppression, a 38% reduction in dry matter production from May to July, was obtained from a mixture of mefluidide and paclobutrazol. Differences were observed between the effects of the shoot-acting retardants, maleic hydrazide and mefluidide and the root-acting retardants, paclobutrazol and EL500. Shoot-acting retardants were less effective in wet weather and lasted for a shorter period than root-acting retardants. They also increased compensatory growth after a period of growth suppression, and increased the proportion of clover in the sward.     

5种甾醇生物合成抑制剂类(SBIs)抗真菌药物对9种植物病原真菌的活性筛选

为了寻找高效、低毒以及环境友好型的农药先导化合物,通过菌丝生长速率法测定了5种甾醇生物合成抑制剂类(SBIs)抗真菌药物(益康唑、氟康唑、伏立康唑、酮康唑和咪康唑)对7种植物病原菌的抑制效果,选择其中活性较高的药物进行了防治小麦白粉病和水稻纹枯病的盆栽试验及防治小麦条锈病和水稻纹枯病的田间药效试验。室内毒力测定结果表明:伏立康唑对供试的7种植物病原真菌的杀菌活性最高,其EC50值均低于0.349 mg/L,咪康唑对小麦赤霉病菌、梨黑斑病菌、西瓜枯萎病菌和香樟炭疽病菌,益康唑对梨黑斑病菌和西瓜枯萎病菌,以及酮康唑对水稻稻瘟病菌均表现出较强的杀菌活性,且均高于对照药剂苯醚甲环唑。盆栽试验结果显示:在药剂质量浓度为37.5 mg/L时,伏立康唑和氟康唑对小麦白粉病的防治效果分别为98.26%和89.11%,明显高于商品化杀菌剂三唑醇;在质量浓度为150 mg/L时,益康唑对水稻纹枯病的防治效果最好,为86.14%。田间试验结果表明:在有效剂量为240 g/hm^2时,氟康唑对小麦条锈病的防效为98.42%,益康唑对水稻纹枯病的防效为75.21%。研究结果表明,临床上的抗真菌药物氟康唑、伏立康唑和益康唑对植物病原真菌也具有很高的活性,可望作为农用杀菌剂的先导化合物进一步研究。     

多效唑在油菜植株、油菜籽和土壤中的残留

研究了多效唑在油菜植株、土壤以及油菜籽中的残留分析方法及残留动态。样品采用二氯甲烷提取,硅镁吸附剂层析柱净化,气相色谱测定。结果表明:多效唑在油菜植株、土壤和油菜籽中的添加回收率分别为88.10% ~110.2%、93.4% ~108.8%和 83.5% ~108.7%;变异系数分别为:1.09% ~5.27%、1.47% ~3.36%和 0.98% ~5.13%。多效唑的最小检出量为1.0×10-11 g,土样、植株、油菜籽中的多效唑最低检出浓度分别为0.01、0.05和0.05 mg/kg。多效唑在植株和土壤中的半衰期分别是4.80 ~7.12 d和 12.31 ~17.11 d,在植株中的降解速率大于在土壤中的降解速率。     

啶菌口恶唑Z、E异构体的拆分及其抑菌活性比较

 啶菌口恶唑是一个新型异口恶唑类广谱杀菌剂,为探索其异构体的抑菌活性差异,采用薄层层析、柱层析和高效液相色谱法对啶菌口恶唑顺反异构体进行了分离和纯度检测,并测定了其对担子菌门、子囊菌门和无性型真菌类14个属16株植物病原真菌的离体活性。试验分离获得了纯度分别为94.9%和95.0%的啶菌口恶唑Z、E异构体。离体条件下,Z异构体对供试病原真菌EC₅₀值范围为0.000 2～0.730 3 μg/mL,E异构体EC₅₀值范围为0.003 1～49.182 7 μg/mL,Z异构体对14株病原菌抑菌活性显著(P＜0.01)高于E异构体。     

Insecticidal and fungicidal activity of new synthesized chitosan derivatives

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.     

不同浓度苦参提取物对蔬菜病原菌的抑菌活性

采用生长速率法和悬滴法室内测试了不同浓度苦参提取物对葱菌核菌、番茄早疫菌、菜豆根腐菌、辣椒枯萎菌、黄瓜枯萎菌、茄子黄萎菌等6种蔬菜病原菌的抑菌活性。结果表明:苦参提取物对供试病菌菌丝生长和孢子萌发均有很强的抑制作用。在供试质量浓度10mg/mL时,对辣椒枯萎菌、葱菌核菌、菜豆根腐菌、黄瓜枯萎菌菌丝生长的抑制率均在61%以上;在供试质量浓度30mg/mL时,对辣椒枯萎菌、菜豆根腐菌、黄瓜枯萎菌、番茄早疫菌的抑制率均在70%以上,对葱菌核菌的抑制率达81.61%。试验表明,随着苦参提取液浓度的升高对供试菌孢子萌发抑制作用增强。在供试质量浓度30mg/mL时,孢子萌发抑制率均在77.04%以上。     

多效唑在茄子中的消解动态与急性膳食摄入风险评估

建立了茄子中多效唑残留的分析方法,开展了规范残留试验并监测了多效唑对茄子生长和品质的影响,同时对茄子中多效唑残留带来的急性膳食摄入风险进行了评估。样品经乙酸-乙腈提取,超高效液相色谱-串联质谱（UPLC-MS/MS）检测,外标法定量。结果表明:在0.02~5.0 mg/L范围内多效唑的质量浓度与对应的峰面积间线性关系良好,方法的检出限（LOD）为0.005 mg/kg,在茄子中的定量限（LOQ）为0.02 mg/kg。在0.02、0.10和0.20 mg/kg 3个添加水平下,多效唑在茄子中的回收率为88%~92%,相对标准偏差为5.1%~6.9%。其消解规律符合一级动力学方程,半衰期为1.45 d,正常收获期茄子中的最大残留量为0.02 mg/kg。多效唑可矮化茄子植株,增加产量,提高Vc、可溶性糖和黄酮含量,推荐使用剂量为有效成分12g/hm2,喷施2次。茄子中多效唑残留对中国各类人群的膳食摄入暴露量为0.70~1.9 μg/（kgbw·d）,仅占ARfD的0.70%~1.9%,在可接受范围内,说明茄子中多效唑残留带来的膳食摄入风险极低。     

菲并吲哚里西啶生物碱及其盐衍生物 的生物活性研究

分别采用菌丝生长速率法和盆栽法,测定了一系列菲并吲哚里西啶生物碱及其盐衍生物的杀菌及除草活性。结果表明:该类生物碱及其盐衍生物表现出了很好的杀菌活性,尤其是生物碱安托芬 ± )-antofine]( 2 )和脱氧娃儿藤宁碱 ± )-deoxytylophorinine]( 3 )在50 μ g/mL下,对番茄早疫Alternaria solani、花生褐斑Cercospora arachidicola、苹果轮纹Physalospora piricola 和黄瓜枯萎Cladosporium cucumerium 4种菌体的抑制率达70%~100%;但未表现出明显的除草活性。     

Effects of Cytochrome P450-Interacting Plant Growth Retardants,Fungicides and Related Compounds on Cell Development and Phase-I Biotransformation Capacity of Unicellular Photoautotrophic Green Algae

Fourteen compounds (paclobutrazol, triadimenol, BAS111..W, propiconazole, tetcyclacis, prochloraz, metyrapone, piperonyl butoxide, 1-aminobenzotriazole, fenpropimorph, propham, prohexadione, mepiquat chloride and chlormequat chloride), most of them established inhibitors of cytochrome P450-dependent mixed function oxygenases and used as pesticides, especially plant growth regulators or fungicides, were applied to the non-target organisms Chlorella fusca and Chlorella sorokiniana, two species of photoautotrophic unicellular green algae. The inhibitory properties of these compounds were evaluated by comparing concentration/response relationships for the integral parameters of cell volume growth and cell division with those for the P450-dependent O-dealkylase activity measured in vivo using 7-ethoxycoumarin and 7-ethoxyresorufin as xenobiotic model substrates for phase-I biotransformation. The results obtained indicate a strong algicidal activity for some of these compounds, with differential sensitivity of the order: cell division>O-dealkylation>cell volume increase. EC₅₀ values for cell division of C. fusca ranged from 0·1 to 9·3 μmol litre⁻¹ for prochloraz and paclobutrazol, respectively. Furthermore, in most cases, concentrations around 10 μmol litre⁻¹ limited significantly the capacity for cytochrome P450 O-dealkylase activity.     

含肟醚并取代异 NFDA1唑环的氨基甲酸酯类化合物的合成及生物活性

为寻找具有优异生物活性的氨基甲酸酯类化合物,根据活性亚结构拼接原理,将取代异 NFDA1 唑和肟醚基团引入多菌灵结构中,以取代苯甲醛 (1) 和2-氯苄胺(3) 为起始原料,经多步反应设计合成了10个未见文献报道的含肟醚并取代异 NFDA1 唑的氨基甲酸酯类化合物,其结构经 1H NMR 和 MS 确证。初步生物活性测定结果表明,部分目标化合物不仅具有一定的杀菌活性,同时还具有较好的除草活性。其中,活体盆栽试验结果表明,化合物11b对黄瓜霜霉病Pseudoperonospora cubensis 的相对防效为90%,对黄瓜白粉病Sphaerotheca fuliginea 的相对防效达95%,低于对照药剂多菌灵;除草活性皿测法表明,化合物11c和11j 200 mg/L下对靶标作物的根、茎抑制率均达80%以上,与对照药剂异丙酯草醚活性相当。盆栽法表明,150 g/hm2下,化合物11c和11j对繁缕Stellaria media苗前和苗后的抑制率均在70%以上,低于异丙酯草醚。此类化合物的构效关系有待进一步研究。