Molluscicidal and anti-feedant activities of diterpenes from Euphorbia paralias L

Nine known diterpene polyesters of segetanes, jatrophenes and paralianes have been isolated from the aerial parts of Euphorbia paralias L. The molluscicidal activity of isolated compounds was evaluated on Biomphalaria alexandrina (Ehrenberg). Paraliane diterpene, (2S,3S,4R,5R,6R,8R,12S,13S,14R,15R)-5,8,14-triacetoxy-3-benzoyloxy-15- hydroxy-9-oxo-paraliane, was the most potent compound against the snail. Anti-feedant activity was tested by a conventional leaf disc method against third-instar larvae of Spodoptera littoralis (Boisd). Jatrophene diterpene, (2R,3R,4S,5R,7S,8R,13R,15R)-2,3,5,7,15-pentaacetoxy-8-angeloyloxy-14,15- dioxojatropha-6(17)-11E-diene, had the highest anti-feedant activity among the compounds tested.     

含苯丙氨酸和1H-茚-1-酮类氯虫苯甲酰胺类似物的合成及杀虫活性

为了开发新的杀虫化合物，以氯虫苯甲酰胺为先导，2-甲基-3-氨基苯甲酸为起始原料，经过卤化生成5-氯-3-甲基-2-氨基苯甲酸；再与3-溴-1-(3-氯吡啶-2-吡啶基)-1H-吡唑-5-甲酸进行缩合反应，生成6-氯-2-(3-溴-1-(3-氯吡啶-2-吡啶基)-1H-吡唑-5-基)-8-甲基-4H-3,1-苯并噁嗪-4-酮；最后引入苯丙氨酸片段并经环化反应，分别合成了两个系列共计23 个新化合物( 4 和 5 )，其中化合物 4 为含苯丙氨酸的氯虫苯甲酰胺类似物，化合物 5 为由化合物4环化生成的含1H-茚-1-酮片段的氯虫苯甲酰胺类似物，所有化合物的结构均通过核磁共振氢谱(1H NMR)、碳谱(13C NMR)和高分辨质谱(HRMS)的表征及确证。初步室内杀虫活性测试结果表明，多数目标化合物对黏虫Mythinma separata具有较高的杀虫活性，其中14个化合物在100 mg/L下对黏虫Mythinma separata的致死率为100%，化合物 5k ( 1H-茚-1-酮片段中取代基为羟基 ) 在4和0.8 mg/L下的致死率分别为90%和70%，其LC₅₀值为0.55 mg/L。分子对接结果表明，化合物 5k 与氯虫苯甲酰胺一样，也是作用于鱼尼汀受体(RyR)，但与靶标结合的氨基酸残基不同，这种差异可能对黏虫的抗药性治理研究有益。     

Absorption and distribution of intubated insecticides in fasted mice

Radioactive solutions of ¹⁴C-labeled insecticides were administered by stomach needle to fasted female mice (1 mg/kg, Dublin strain). They were killed at different time intervals and the amount of radioactivity determined in the gastrointestinal tract (unabsorbed) and in selected organs. T_0.5 values of penetration (min) ranged from 8 to 17 for the carbamates tested, 24 to 78 for the organophosphorus compounds, and 15 to 62 for the chlorinated hydrocarbons. Among other insecticide groups, nicotine penetrated rapidly whereas permethrin was the least rapid of all compounds under study. The insecticides were rapidly distributed to various organs. No consistent correlations between absorption and physicochemical properties of the compounds were noted.     

1997~2001年我国小麦条锈菌生理小种变化动态

 1997~2001年采自我国13个省和自治区的主要生产品种和重要抗源上的小麦条锈菌标样4008份,其鉴定结果基本反映了这期间我国小麦条锈菌生理小种的变化状况。1997年发现了水源11致病类型13和14,2001年把原Hybrid 46致病类型3(HY-3)命名为条中32号。这期间共监测到41个小种和致病类型,每年都能监测到的小种和致病类型有32个,为条中17、19、21、22、23、25、26、28号,洛10-2,条中29,洛13-2、3,条中30、31、32,Hybrid 46-4、5、6、7、8,水源11-2、3、4、5、6、7、8、10、11、12、13和14。条中29、30、31、32号为主要流行小种。1997~2000年间条中31号位居第一,出现频率为10.8%~13.5%,其次为条中32号(4.8%~11.7%),由于条中32号逐年持续上升,2001年超过条中31号而位居第一。其次是条中29和30号,两者出现频率基本相当,1997~1999年条中29号略高位第3(3.3%~4.0%),条中30号位第4(2.6%~3.3%),2000~2001年,条中30号略高位第3(3.6%~7.3%),条中29号位第4(2.7%~3.1%)。出现频率较高的还有条中23号、25号、26号、28号和Hybrid 46-4、5、7、8,水源11-3、4、5、7、11、13和14,其它为稀有小种和致病类型。相对于东部黄淮海流域,甘肃、四川、陕南和云南及其毗邻地区条锈菌群体结构复杂,内部多样性高,几乎所有小种和致病类型都可监测到。从整个条锈菌群体衡量Hybrid 46和水源11致病类群占有很大份额,1997~2001年两者总的年出现频率分别为78.5%、80.2%、76.6%、78.7%和87.4%,致使我国小麦条锈菌群体均匀度低,这与我国小麦品种抗病基因较简单、且主要集中在Yr9为重要抗源的"洛类"衍生系(80%以上)和以繁6为抗源的繁6衍生系有一定关系。     

金丝草抑菌活性成分研究

为探索金丝草Pogonatherum crinitum在植物病原菌防治方面的应用前景,测定了金丝草水提取物及其乙酸乙酯、正丁醇萃取物对20种常见农作物病原真菌的抑菌活性。结果表明,2.00×103 mg/L的乙酸乙酯萃取物对其中8种植物病原菌的抑制率大于50%,尤其对辣椒疫霉Phytophthora capsici的抑制率高达100%。由乙酸乙酯萃取物进一步分离得到10个已知化合物,经波谱学方法鉴定其分别为1,2,4-三羟基苯（ 1 ）、1,2-二羟基-4-甲氧基苯（ 2 ）、小麦黄素-7-O-β-D-吡喃葡萄糖苷（ 3 ）、小麦黄素（ 4 ）、β-腺苷（ 5 ）、咖啡酸（ 6 ）、留兰香木脂素B（ 7 ）、木犀草素6-C-β-波依文糖-7-O-β-葡萄糖（ 8 ）、芦丁（ 9 ）及槲皮素（ 10 ）,其中化合物 2、3、5、7 和 10 为从该植物中首次分离得到。孢子萌发法测定结果表明:化合物 6~10 对棉花立枯丝核菌Rhizoctonia solani和辣椒疫霉的孢子萌发具有较好的抑制作用,其EC₅₀值分别在18.54~103.6 mg/L和21.38~87.83 mg/L之间。     

Studies on the mode of action of asulam,aminotriazole and glyphosate in Equisetum arvense L. (field horsetail). II: The metabolism of [14C]asulam, [14C]aminotriazole and [14C]glyphosate

The metabolism of [¹⁴C]asulam (methyl 4-aminophenylsulphonylcarbamate), [¹⁴C] aminotriazole (1H-1,2,4-triazol-3-ylamine) and [¹⁴C]glyphosate (N-(phosphonomethyl)glycine) were assessed in Equisetum arvense L. (field horsetail). Following application of the test herbicides (4mg?0.3 °Ci herbicide/shoot) to the shoots of 2-year-old pot-grown plants, the total recovery of ¹⁴C-label after 1 week and 8 weeks was high for all three herbicides (>80-0% of applied radioactivity). Asulam was persistent (>69-7% of recovered radioactivity) in both shoots and rhizomes. Sulphanilamide, a hydrolysis product of asulam, accounted for the remainder of the recovered radioactivity. Aminotriazole showed evidence of conjugation in shoots and rhizomes. The principal ¹⁴C-labelled component in shoots was composed of high proportions of aminotriazole (>76-3%) together with the metabolites: X (ninhydrin positive), β-(3-amino-1,2,4-triazolyl-1-)α-alanine, Y (diazotization positive) and various unidentified compounds. Rhizomes generally contained lower proportions of intact aminotriazole (>59.4%) together with the metabolites X,Y and unidentified compounds. The proportion of aminotriazole did not decrease with time in shoots or rhizomes; however, the ratio of metabolite X: Y moved in favour of Y as the interval after treatment increased. Glyphosate was extensively metabolised in shoots and rhizomes to yield aminomethylphosphonic acid (AMPA) and various unidentified compounds. Differential metabolism appears to be one of the factors which may govern the persistence and toxicity of the test herbicides in E. arvense.     

Effects of photoperiod on the development and growth of <Emphasis Type="Italic">Podisus nigrispinus</Emphasis>, a predator of cotton leafworm

The effects of photoperiod on nymphal development, growth and adult size in Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) were studied. Predators were collected in cotton fields in Patos (7°S, 37°W), Paraíba State, Brazil. A randomized block experimental design was used, with treatments consisting of photoperiods of 10L:14D, 11L:13D, 12L:12D, 13L:11D, 14L:10D, 15L:9D and 16L:8D (LD, in h), at a constant temperature of 28 ± 1°C and relative air humidity of 70 ± 10%. Treatments were distributed in four replications, with each experimental unit composed of 40 nymphs. The development period for each instar of P. nigrispinus varied according to the photoperiod exposure. Regardless of the photophase (PhP), the 5th instar nymphs exhibited the longest development period, except for the 15-h PhP, in which the development period of 2nd instar nymphs (4.13 days) was as long as that of the 5th instar nymphs (4.23 days). In the 1st, 3rd and 5th instars of P. nigrispinus, the development period was inversely proportional to the increase in light period in which the nymphs developed, for the PhP intervals of 10–14 h, 12–14 h, and 12–15 h, respectively. Predators exposed to a 14-h PhP developed a wider pronotum than those exposed to extreme PhP’s (of 10 h, 11 h and 16 h). Conditions from 14 h to 15 h of light resulted in higher daily growth rates in P. nigrispinus than those obtained with the other PhP’s tested. P. nigrispinus females exhibited faster daily growth rates than did males.     

Mechanism of metribuzin tolerance: herbicide metabolism as a basis for tolerance in potatoes*

¹⁴C-5(ring)-metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as triazin-5(4H)-one] metabolism was studied in ‘Russet Burbank’ and ‘Chipbelle’ potato (Solanum tuberosum L.) cultivars after root treatment in hydroponic solution. Plants were treated at the four- to five-leaf stage and harvested 1, 4, and 8 days later. Extraction was made by homogenizing dried samples in 80% methanol and partitioning against diethyl ether. Metabolites were partially characterized by thin-layer chromatography (t.l.c.) and compared to known standard chemicals, except for conjugates for which we had no synthetic standards. Ether-soluble chemicals [metribuzin and diketo (DK), deaminated (DA), and deaminated diketo (DADK) forms] comprised 55, 37, and 36% of the total ¹⁴C in Chipbelle plants and in Russet Burbank 30, 15, and 13% at 1, 4, and 8 days, respectively. Metribuzin and DK, DA, and DADK were present in all organs of each cultivar, but Russet Burbank leaves had only 5% as much free metribuzin as did Chipbelle. Most radioactivity in the leaves was a conjugate form which comprised 81 and 46% of the total ¹⁴C in Russet Burbank and Chipbelle leaf blades at 8 days, respectively. There were five water-soluble conjugates separated which included two ninhydrin-reacting compounds and three conjugates reacting as sugars. The major foliar conjugates reacted as sugars and the major root conjugates reacted as peptides or amino acid for both cultivars. Terminal (insoluble) residues comprised 63 and 66% of total radioactivity in roots of Russet Burbank and Chipbelle, respectively after 4 or 8 days. The major mechanism of Russet Burbank tolerance to metribuzin is conjugation of metribuzin or DA, DK, or DADK derivatives to plant sugars or peptides. Mécanisme de tolérance à la métribuzine; le métabolisme de l'herbicide—base de la sélectivité sur pommes de terre Le mécanisme du métabolisme de la C¹⁴ métribuzine [4-amino-6-tert butyl-3- (methylthio)-as triazine 5 (4H)-one] a étéétudié sur les cultures de pommes de terre ‘Russet Burbank’ et ‘Chipbelle’ après traitement des racines dans une solution hydroponique. Les plants étaient traités au stade 4–5 feuilles et récoltes 1, 4 et 8 jours plus tard. L'extraction était faite à partir d'échantillons secs homogènes dans une solution à 80% de méthanol et séparés par du diéthylether. Les métabolites ont été en partie caractérisées par chromatographie sur couche mince (CCM) et comparés à des standards chimiques, excepté pour les composés pour lesquels il n'y a pas de standards de synthèse. Les substances chimiques solubles dans l'éther [métribuzine et diketo (DK), formes désaminèes (DA) et formes diketo désaminées (DADK)] comprenaient 55, 37 et 36% du total du C¹⁴ dans les plants Chipbelle et 30, 15 et 13% dans les Russet Burbank à respectivement 1, 4 et 8 jours. Metribuzine et DK, DA et DADK étaient présents dans tous les organes de chaque cultivarmais les feuilles de Russet Burbank avaient seulement 5% de la quantité de métribuzine libre présente dans Chipbelle. La plus grande partie de la radioactivité dans les feuilles était liée à une forme conjuguée comprenant respectivement 81 et 46%, du C¹⁴ total dans les limbes des feuilles de Russet Burbank et de Chipbelle. II y avait 5 composés solubles dans I'eau qui comprenaient 2 composés réagissant à la ninhydrine et 3 composés réagissant comme des sucres. La majeure partie des composés foliaires réagissait comme des sucres et la majeure partie des composés racinaires comme des peptides et des aeides aminés pour les deux cultivars. Les résidus finaux (insolubles) comprenaient respectivement 63 et 66%, de la radioactivité totale dans les racines de Russet Burbank et Chipbelle après 4 ou 8 jours. Le principal mécanisme de la tolérance de Russet Burbank à la métribuzine est la conjugaison de la métribuzine ou des dérivés DA, DK ou DADK aux sucres ou peptides de la plante. Mechanismus der Toleranz gegenüber Metribuzin: Herbizid-Metabolismus als Basis der Toleranz der Kartoffel (Solanum tuberosum L.) Der Metabolismus von ¹⁴C-ringmarkiertem Metribuzin wurde durch Applikation in Hydroponik an den Kartoffelsorten ‘Russet Burbank’ und ‘Chipbelle’ untersucht. Die Pflanzen wurden im 4- bis 5-Blatt-Stadium behandelt, und I, 4 und 8 Tage später wurden Proben entnommen, die nach dem Trocknen mit 80% igem Methanol extrahiert und in die Diethylätherphase überführt wurden. Die Metaboliten wurden teilweise dünnschicht chromatographisch im Vergleich zu bekannten Standards charakterisiert. Die etherlöslichen Stoffe [Metribuzin sowie die Diketo-(DK), die deaminierte (DA) und die deaminerte Diketoform (DADK)] ergaben bei den 3 Probe-nahmeterminen 55, 37 und 36% des gesamten ¹⁴C bei der Sorte ‘Chipbelle’ bzw. 30, 15 und 13% bei ‘Russet Burbank’. Das Metribuzin sowie DK, DA und DADK waren in allen Pflanzenteilen zu finden, aber die ‘Russet-Burbank’-Blätter enthielten nur 5% der Metribuzinmenge bei ‘Chipbelle’. Die Hauptaktivität lag in den Blättern (8 Tage nach der Applikation) in konjugierter Form vor und representierte 81% der Gesamtaktivität bei ‘Russet Burbank’, 46% bei ‘Chipbelte’. Es wurden 5 wasserlösliche Verbindungen gefunden, von denen 2 auf Ninhydrin reagierten und 3 als Zucker identifiziert wurden. Bei beiden Sorten waren die meisten Verbindungen in den Blättern Zucker, in den Wurzeln Peptide oder Aminosäuren. Die unlöslichen Rückstände der Proben enthielten beim 2. und 3. Probenahmelermin 63 bzw. 66%, der gesamten ¹⁴C-Aktivität. Der wichtigste Mechanismus der Toleranz von ‘Russel Burbank’ gegenüber Metribuzin besteht in der Bindung des Wirkstoffs oder der Metabolite DA, DK und DADK an Zucker oder Peptide.     

Control of Aspergillus growth and aflatoxin production using natural maize phytochemicals under different conditions of water activity

The effects of the natural phytochemicals trans-cinnamic acid (CA) and ferulic acid (FA) alone at concentrations of 1-25 mM and in 16 combinations (M: mixtures) on growth and aflatoxin B(1) production by Aspergillus flavus Link and A. parasiticus Speare were evaluated. Studies on growth rate and aflatoxin B(1) production were carried out in vitro in relation to a water activity a(w) of 0.999, 0.971, 0.955 and 0.937. Overall, CA at concentrations of 10 and 20 mM and FA-CA mixtures M3 (20 + 5 mM respectively), M8 (25 + 5 mM), M9 (1 + 10 mM), M10 (10 + 10 mM), M11 (20 + 10 mM), M12 (25 + 10 mM), M13 (1 + 20 mM), M14 (10 + 20 mM), M15 (20 + 20 mM) and M16 (25 + 20 mM) were the treatments most effective at inhibiting growth of the four species assayed. All strains were much more sensitive to all natural phytochemicals tested on growth rate at a(w) = 0.937. CA and the FA-CA mixtures M1 (1 + 1 mM respectively), M4 (25 + 1 mM), M5 (1 + 5 mM), M6 (10 + 1 mM), M7 (20 + 1 mM), M8 (25 + 5 mM), M9 (1 + 10 mM), M10 (10 + 10 mM), M11 (20 + 10 mM), M12 (25 + 10 mM), M13 (1 + 20 mM), M14 (10 + 20 mM), M15 (20 + 20 mM) and M16 (25 + 20 mM) completely inhibited aflatoxin B(1) production by all strains at a(w) = 0.999, 0.971, 0.955 and 0.937. Decreased aflatoxin B(1) levels in comparison with the control were observed with FA at 1, 10, 20 and 25 mM with the strains RCM89, RCM108 and RCM38 at a(w) = 0.971, 0.955 and 0.999 respectively. The data show that CA and FA can be considered as effective fungitoxicants for A. flavus and A. parasiticus in in vitro assay. The information obtained is part of an ongoing study to determine their application at the storage level.     

Effect of fenpropimorph and imazalil on sterol biosynthesis in penicillium italicum

Fenpropimorph was found to be highly active against Penicillium italicum (EC₅₀ 0.01/μg ml^?1). Conidia of P. italicum, treated with low concentrations of fenpropimorph, swelled in size and showed distorted germ tubes. During the initial stages of mycelial growth, fenpropimorph had little or no effect on the dry weight increase, which became strongly inhibited within 24 h after addition of the toxicant (0.05, 0.1 and 0.2 μg ml^?1). Irregular deposition of β–1,3 and β–1, 4 polysaccharides, probably chitin, was observed after treatment with fenpropimorph or imazalil. Fenpropimorph (0.05 and 0.2 μ ml^?1) caused the accumulation of a major demethyl-sterol that was different from ergosterol. It was identified as ergosta-8, 14, 24(28)-trien-3β-ol by mass, infrared, ultraviolet and proton nuclear magnetic resonance, spectrometric procedures. At both concentrations, the accumulation was already detected after incubation for 2 h. In contrast, imazalil (0.1 μg ml^?1) caused the accumulation of several methyl- and dimethyl-sterols which were tentatively identified as eburicol (24-methylene-24, 25-dihydrolanosterol), 4, 14α-dimethylergosta-8, 24(28)-dien-3-one, 14α-methylergosta-8, 24(28)-dien-3-one and obtusifoliol (4, 14α-dimethylergosta-8, 24(28)-dien-3α-ol). The accumulation of ergosta-8, 14,24(28)-trien-3β-ol indicates inhibition of the Δ¹⁴-reductase in P. italicum in a similar manner to that found previously in Ustilago maydis.     

冠菌素对玉米抗倒伏能力及产量的影响

在田间条件下,以玉米品种先玉335和郑单958为材料,在八展叶时于叶面喷施不同浓度 (0、0.01、0.1、1和10 μmol/L) 冠菌素 (COR),研究了COR对玉米抗倒伏能力及产量的影响。结果表明:经10 μmol/L COR处理后,先玉335的株高和穗位高分别比对照降低了7.0%和19.9%,郑单958分别降低了20.8%和18.2%,单株叶面积、节间抗折断力、穗下第8~14节间长度和节间最大直径与对照间亦差异显著。且随着COR浓度的增加,先玉335和郑单958的株高、穗位高、单株叶面积和穗下第8~14 节间长度均逐渐降低;第8~14节间最大直径和节间抗折断力逐渐增大。经1 μmol/L COR处理后,2个供试玉米品种的产量、穗数、穗粒数和千粒重较对照均有所增加,其中先玉335的产量较对照增加了9.9%,郑单958增加了4.3%。综上所述,COR可以提高玉米的抗倒伏能力,不同品种玉米对COR的敏感性不同,其中先玉335抗倒伏的最适COR浓度为10 μmol/L,郑单958抗倒伏的最适COR浓度为1 μmol/L。     

Synthesis of allylic trifluoromethyl ketones and their activity as inhibitors of the sex pheromone of the leopard moth, Zeuzera pyrina L. (Lepidoptera: Cossidae)

BACKGROUND: Trifluoromethyl ketones (TFMKs), structurally related to the pheromones, are good inhibitors of pheromone communication in insects. To determine their activity on Zeuzera pyrina L. (Lepidoptera: Cossidae), a polyphagous pest, the authors have prepared two diunsaturated TFMK analogues of the major (3) and the minor (4) pheromone components, and two monounsaturated ones (5, 6). Their biological activity in electroantennogram (EAG), wind tunnel and field tests is presented. RESULTS: The synthetic strategy to obtain the allylic TFMKs 3 and 5 is based on the reactions of diene 10 and 1‐octadecene with trifluoroacetaldehyde ethyl hemiacetal, followed by Dess–Martin oxidation of the resulting homoallylic trifluoromethyl alcohols. In EAG, topical application of analogues 3 and 4 on male antennae significantly reduced the pheromone response. In the wind tunnel, compound 4 reduced the number of contacts with the pheromone source. In the field, traps baited with mixtures of pheromone and inhibitors captured significantly fewer males than the pheromone alone. CONCLUSION: An efficient synthesis of allylic TFMKs is reported, with good overall yield, regiospecificity and diastereoselectivity. These compounds are good inhibitors of the pheromone in electrophysiology, wind tunnel and field tests. The results show the importance of two unsaturations at positions 2 and 13 of the trifluoroacyl group in the structure of the analogues, the latter being critical for inhibitory activity. Copyright © 2011 Society of Chemical Industry     

Comparison of Different Greenhouse Systems and Their Impacts on Plant Responses of Tomatoes

A semi-closed greenhouse was used for sustainable tomato production and to investigate the effects of the prevailing climate conditions within this greenhouse on different plant parameters of tomatoes. Compared to conventionally cultivated tomato plants, the leaf area index, the number of trusses and the yield of marketable fruit of tomato plants exposed to the microclimatic conditions in the semi-closed greenhouse were significantly increased by 21, 11 and 31.9?%, respectively. Furthermore, the application of this new technology led to a significant increase in contents of lycopene (by 30?%), ß-carotene (by 40?%), phenolic compounds (25?%), titratable acids (by 8?%) and soluble solids (by 15?%) in tomatoes during the summer period. These results were attributed to higher photosynthetic activities, which predominantly occurred in the greenhouse with the semi-closed operation mode. Furthermore, the new technology can be seen as new horticultural approach to reduce the yield of blossom-end rot fruit by 75.2?%. This quality improvement was caused by higher levels of relative humidity, where this humidity states were also responsible for a reduction in the annual plant transpiration rate by 10?%.     

大蓟地上组织化学成分及其抗真菌活性

为筛选新型植物源杀菌剂,对大蓟Cirsium japonicum地上组织的化学成分及其抑菌活性进行了系统研究。采用甲醇提取,液-液萃取分离、硅胶柱层析及凝胶层析等技术从乙酸乙酯相中分离得到13个化合物。利用质谱和核磁共振等波谱技术确定其结构分别为ciryneol D ( 1 )、12β, 20 (S)-二羟基达玛烷-24-烯-3-酮 ( 2 )、3β-羟基-9 (11),12-齐墩果二烯 ( 3 )、蒲公英甾醇 ( 4 )、3β-羟基豆甾-5-烯-7-酮 ( 5 )、3β-羟基-12 (13)-烯-齐墩果烷-11-酮 ( 6 )、对香豆酸 ( 7 )、(3-甲氧基酰氨基-4-甲基苯)-氨基甲酸甲酯 ( 8 )、对羟基苯甲酸酯 ( 9 )、4,4′-甲氧羰基氨基二苯甲烷 ( 10 )、槲皮苷 ( 11 )、山柰酚-3-O-α-L-鼠李糖苷 ( 12 ) 和柯伊利素-7-O-2′-O-6′-O-乙酰基-β-D-吡喃葡萄糖基-β-D-吡喃葡萄糖苷 ( 13 ),其中,化合物 2 、 3 、 6 、 8 、 10 、 12 和 13 均为首次从大蓟中分离得到。生物测定结果表明:ciryneol D ( 1 ) 对多种真菌菌丝生长表现出明显抑制作用,其中对苹果腐烂病原菌Valsa mali的抑制效果最好,EC₅₀值为23.2 μg/mL,对玉米弯孢病菌Curvularia lunata、苹果炭疽病菌Colletotrichum gloesporioides及番茄灰霉病菌Botrytis cinerea的孢子萌发也具有明显的抑制作用,EC₅₀值分别为27.5、26.4和81.9 μg/mL。     

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。     

Compounds from Ageratum conyzoides: isolation, structural elucidation and insecticidal activity

This work aimed at identifying plant compounds with insecticidal activity against Diaphania hyalinata (L.) (Lepidoptera: Pyralidae), Musca domestica (L.) (Diptera: Muscidae), Periplaneta americana (L.) (Blattodea: Blattidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae). The plant species used were: basil (Ocimum selloi Benth.), rue (Ruta graveolens L.), lion's ear (Leonotis nepetaefolia L.), Jimson weed (Datura stramonium L.), 'baleeira' herb (Cordia verbenaceae L.), mint (Mentha piperita L.), wild balsam apple (Mormodica charantia L.) and billy goat weed (Ageratum conyzoides L.). Firstly, the insecticidal activities of hexane and ethanol plant extracts were evaluated against adults of R. dominica. Among them, only the hexane extract of A. conyzoides showed insecticidal activity. The hexane extract of this plant species was therefore fractionated by silica gel column chromatography to isolate and purify its bioactive chemical constituents. Three compounds were identified using IR spectra, (1)H NMR, (13)C NMR, HMBC and NOE after gel chromatography: 5,6,7,8,3', 4', 5'-heptamethoxyflavone, 5,6,7,8,3'-pentamethoxy-4', 5'-methylenedioxyflavone and coumarin. The complete assignment of (13)C NMR to 5,6,7,8,3'-pentamethoxy-4', 5'-methylenedioxyflavone was successfully made for the first time. 5,6,7,8,3'-Pentamethoxy-4', 5'-methylenedioxyflavone did not show any insecticidal activity against the four insect species tested. 5,6,7,8,3', 4', 5'-Heptamethoxyflavone showed low activity against D. hyalinata and R. dominica and was not toxic to M. domestica or P. americana. In contrast, coumarin showed insecticidal activity against all four insect pest species tested, with the following order of susceptibility: R. dominica < P. americana < D. hyalinata < M. domestica after 24 h exposure.     

The effect of condensed tannins from seven herbages on Trichostrongylus colubriformis larval migration in vitro

The effects of condensed tannins (CT) extracted from seven forages on the motility of the economically important nematode, Trichostrongylus colubriformis (Giles, 1892), were evaluated by using a larval migration inhibition (LMI) assay. The assay involved incubation of third stage (L3) exsheathed T. colubriformis larvae with CT extracted from Lotus pedunculatus, Lotus corniculatus, sulla (Hedysarum coronarium), sainfoin (Onobrychis viciifolia), Dorycnium rectum, Dorycnium pentaphyllum and dock (Rumex obtusifolius) and measurement of larval migration through nylon mesh with a 20 microm pore size. At 100 microg ml(-1), CT from L. pedunculatus, L. corniculatus, sulla, sainfoin, D. rectum, D. pentaphyllum and dock inhibited 20%, 10%, 15%, 25%, 28%, 32% and 27% of the larvae, respectively from passing through the sieves compared to controls (no CT added). At 1000 microg CT ml(-1), CT purified from D. pentaphyllum had the highest inhibitory activity (63%) against 1-month old larvae followed by sainfoin (59%), L. pedunculatus (57%), D. rectum (53%), dock (50%), sulla (40%) and L. corniculatus (37%). Seven-month old larvae were more sensitive to the action of CT than 1-month old larvae (P < 0.001). Addition of 2 microg polyethylene glycol ([PEG] per microg CT; to remove the effect of CT) eliminated 81-93% of the CT activity (P < 0.001) compared to incubations without PEG. The impact of CT on larval migration suggests a possible role for these plants in ruminant diets as a means to reduce dependence upon proprietary anthelmintics.     

The degradation of dinitramine (N3,N3-diethyl 2,4-dinitro-6-trifluoromethyl-m-phenylenediamine) in soil

Radioactive dinitramine (1) was incorporated at $\text{1}\text{2}$ Ib/acre (0.6 ppm) in Anaheim silty loam soil and its degradation studied over an 8-month period. For both specifically—¹⁴CF₃ and -Ring-UL-[¹⁴C] labeled (1), only ca. 20% of the radioactivity was lost from the incorporated zone. Mehanol- or acetonitrile-extractable radioactivity decreased rapidly over the initial 60 days reaching 20% after 244 days. Two compounds were isolated and characterized as (1), 0.05 ppm, and 6-amino-1-ethyl-2-methyl-7-nitro-5-trifluoromethylbenzimidazole (2), 0.06 ppm. Two other compounds were tentatively identified by TLC as monodealkylated dinitramine (3), 0.01 ppm, and 6-amino-2-methyl-7-nitro-5-trifluoromethylbenzimidazole (4), 0.01 ppm, Sodium hydroxide (10%) and anionic surfactant (10%) were effective in removing up to 50% of the residual bound radioactivity (i.e., nonacetonitrile extractable), while dimethylamine (25%) released 26%; extraction by acid was less effective.     

4-取代-2-[(3-三氟甲基)-苯乙烯基]-1,3,4-噁二嗪-5-酮的合成及其生物活性

以3-(3-三氟甲基苯基)-丙烯酸为起始原料,设计并合成了14个4-取代-2-(3-三氟甲基)苯乙烯基-1,3,4-噁二嗪-5-酮衍生物,其化学结构经核磁共振氢谱及元素分析确证。初步的生物活性测定结果表明,该类化合物具有良好的杀虫活性,其中化合物 D-2,D-3,D-4,D-8 在质量浓度为50 mg/L时,对淡色库蚊Culex pipiens pallens的致死率分别为91.7% ,86.1% ,85.5%和93.9%。