大戟狼毒不同部位提取物对朱砂叶螨的触杀活性

研究大戟狼毒不同部位不同溶剂提取物对朱砂叶螨的生物活性。结果表明:大戟狼毒根石油醚提取物杀螨活性高于根的其他溶剂和茎、叶不同溶剂提取物。该提取物对朱砂叶螨雌成螨有较高的触杀活性,质量浓度为1mg·mL-1时,24h后雌成螨的校正死亡率达到52.73%,对卵的效果相对较差,质量浓度为4mg·mL-1时卵的校正死亡率为55.21%。进一步对大戟狼毒根石油醚提取物进行萃取分离及生物活性跟踪测定发现:萃取物中石油醚相的活性明显大于氯仿相和甲醇相;对石油醚萃取物的柱层析分离最终得到16个流分,其中以第11个流分杀螨效果最好,质量浓度为1mg·mL-1时,24h后雌成螨的校正死亡率达到86.67%,质量浓度为4mg·mL-1时卵的校正死亡率为66.33%。     

Estimation of mortality ofDacus xanthodes (Broun) maggots in fumigated and non-fumigated watermelons,a fruitfly (Dipt.: Tephritidae) of plant quarantine importance in the Pacific region

Exports of Tongan watermelons to New Zealand were banned in November 1985 due to encounter ofD. xanthodes maggots. Testing of standard quarantine treatments (methyl bromid fumigation) is rendered difficult due to low infestation rates of fruits in the field, and unsuitability of the host for maggot survival. For experimental testing of mortality rates inD. xanthodes due to both fumigation and host insuitability maggots were reared in papaya, and third instars were transplanted into watermelons before treatment. Four types of handling were tested. (A) two fumigated series with either (A 1) 300 maggots per fruit, rind replaced and sealed with tape, and five holes punched, or (A 2) 200 maggots per fruit, paraffin wax sealed, and one hole. Treatment was 32 g/m³ of methyl bromide for 4 h. (B) two control series with 200 maggots per fruit, wax and one hole, one batch (B 1) kept for 4–5 days, the other (B 2) transported twice and kept for 4 days. Number of maggots treated were 42,400, and numbers of maggots in the control trials were 20,400. Initial mortality of larvae was 98% (A 1), 44% (A 2), 35% (B 1), and 17% (B 2). Initial development into pupae was 1.9% (A 1), 2.5% (A 2), 11.9% (B 1), and 7.7% (B 2). Total mortality (development into adults) was 100% (A 1, and A 2), 97% (B 1), and 97% (B 2).     

外来树种火炬树化感作用的研究

以盐肤木和黄栌为参照树种,用火炬树树叶水浸提液、林下土壤水浸提液浸种24 h,研究了浸提液对侧柏、油松、香椿、臭椿、小麦、小白菜种子萌发及幼苗生长的影响,研究了火炬树的化感作用。结果表明:火炬树完整鲜叶水浸提液处理小白菜种子,其发芽率和发芽势分别为88.0%、82.5%,与对照发芽率(94.0%)和发芽势(91.5%)无显著差异,而破碎鲜叶水浸液则极显著影响小白菜的发芽率和发芽势,分别降低为24.8%和5.0%;火炬树完整鲜叶和破碎鲜叶水浸液都能促进小白菜苗高生长,但都抑制小白菜胚根的伸长。与鲜叶相比,火炬树干叶水浸提液的化感作用明显降低。火炬树破碎鲜叶水浸提液极显著影响小麦发芽率,分别比对照的发芽率和发芽势降低11.0%和83.5%,干叶水浸提液则不影响小麦的发芽率,为95.0%,但发芽势比对照降低23.0%。与盐肤木和黄栌相比,火炬树破碎鲜叶水浸提液对小麦幼茎及胚根生长的抑制作用最强。火炬树破碎鲜叶水浸提液对4个乡土树种的种子萌发产生了不同程度的抑制作用,对香椿及臭椿发芽率的抑制作用极显著。火炬树破碎鲜叶水浸提液对4个树种的苗高以及油松苗胚根的伸长没有显著影响,但却极显著地抑制了侧柏、香椿及臭椿胚根的伸长。火炬树林下表层土壤水浸提液对小麦幼苗的生长没有抑制作用,能明极显著促进香椿的生长;处理55 d时,香椿苗平均高为8.63 cm,极其显著高于对照(5.14 cm)。     

Antimicrobial properties of Indigofera dendroides leaves

The antibacterial and antifungal activities of the aqueous, petroleum ether, methanol extracts and eight TLC fractions of the methanol extract of Indigofera dendroides leaves have been evaluated.     

Efficacy of Neem-Azal S and Margosan-0 against the bean aphid,Aphis fabae Scop.

Margosan-0, a commercial preparation of neem seed kernel extract was tested for its effects as toxicant, deterrent and sterilant against the bean aphidAphis fabae and compared with the German product Neem-Azal S. Second and 4th nymphal instars ofA. fabae, placed on bean plants treated with different concentrations of Margosan-0 or Neem-Azal S, were adversely affected and very high percentage of mortality occurred after 96 hours. In a choice test, higher numbers of adults settled and larviposited on plants treated with Margosan-0 in comparison to the control. Neem-Azal S treated plants showed high deterrence to the adults at high concentrations. The deterrent effect was reflected in a reduced larviposition. Plants treated with different concentrations of either Neem-Azal S or Margosan-0 significantly affected the longevity and fecundity ofA. fabae. The efficacy of Neem-Azal S is more pronounced than that of Margosan-0.     

Zur Wirkung von Bacillus thuringiensis var. israelensis auf die Larven der Stechmücke Culex pipiens molestus

Laboratory infectivity tests were undertaken to investigate the pathogenicity of “Bactimos” (a new commerical bacterial biocide) aginst different instar larvae ofCulex pipiens molestus. The biocide “Bactimos”,Bacillus thuringiensis var.israelensis, was confirmed as pathogenic for mosquito larvae ofC. pipiens molestus. At dosage of 0.000125 mg/250 ml water, mortalities of 25, 98, and 97% were recorded for the 1st, 2nd and 3rd instar larvae after 24 hrs, respectively. Dosage of 0.008 mg/250 ml water proved to kill all types of instar larvae (100% mortality) after 24 hours. Water volumes ranging from 100 to 800 ml, containing 0.005 mg “Bactimos” per each were found to kill the 2nd and 4th instar larvae (90–100% mortality) with no significant differences. In conclusion, it is quite evident that the commerical bacterialbiocide “Bactimos” should be recommended as biomortality agent against mosquito larvae in Upper Egypt.     

Effects and mode of action of some plant extracts on certain plant parasitic nematodes

Exposure to standard solution S extract ofPunica granatum, Thymus vulgaris andArtemisia absinthium for 72 h reduced the numbers of active nematodes by 100% forMeloidogyne incognita and by 95.7%, 71.4% and 42.9% forHelicotylenchus dihystera, respectively. Exposure to S/2 dilutions for 72 h reduced nematode motility by 100%, 77.3 and 72.7% forM. incognita, and by 92.9%, 37,1%, and 37,1% forH. dihystera, respectively. As exposure to S and S/2 extracts ofCitrullus colosynthis andRicinus communis reduced nematode motility by less than 32% forM. incognita and by less than 30% forH. dihystera. WhenM. incognita andH. dihystera were transfered to water for 72h, more than 85% of the individuals resumed normal movement at all extract dilutions except S ofA. absinthium andT. vulgaris and S and S/2 ofP. granatum. However, recovery ofM. incognita was more less than that ofH. dihystera. Exposure to S extracts ofP. granatum andT. vulgaris for 30 days reduced egg-hatching ofM. incognita by 100% and by 98.7% for S/2 dilutions. Also, 98.7% reduction in the egg-hatching was obtained by S ofA. absinthium. Extracts ofC. colosynthsis andR. communis gave less egg-hatching inhibition. Acetylcholinesterase (AChE) activity was suppressed by more than 75% inH. dihystera treated with S of each ofP. granatum, T. vulgaris andA. absinthium. However, the former extract gave the highest AChE inhibition (98.7%). When nematodes were treated with oxamyl (Vydate 24%), AChE activity was suppressed by 53.3%. The other extract dilutions suppressed AChE activity by less than 50%.     

Antimicrobial activity of Cassia alata.

The methanol extracts of leaves, flowers, stem and root barks of Cassia alata showed a broad spectrum of antibacterial activity. The activity was increased on fractionation (petrol, dichloromethane, ethyl acetate), the dichloromethane fraction of the flower extract being the most effective. No activity was shown against tested moulds.     

Antimicrobial activity of Micrechites novoguineensis

The methanol extracts of Micrechites novoguineensis, leaves and stem bark were partitioned (petrol, ethyl acetate, methanol). All obtained fractions showed a broad spectrum of antibacterial activity, while only the leaf ethyl acetate fraction showed activity against moulds.     

Laboratory and field evaluations of some botanical pesticides against the cedar leaf moth, <Emphasis Type="Italic">Acleris undulana</Emphasis>

The cedar leaf moth (CLM), Acleris undulana Walsingham, has recently become an important pest in the cedar forests in southwestern Turkey. Control has focussed on the use of synthetic chemical pesticides, with little research having been conducted on alternative control methods. In this study, four botanical pesticides (two commercial neem products, Neemazal-T/S^® and Greeneem^® oil, and two hot water plant extracts, Origanum onites L. and Pimpinella anisum L.) were evaluated for their effects against young (first–second) and older (third–fifth) instar larvae of CLM under laboratory and field conditions. The results of larval dip bioassay in the laboratory showed that all the botanical pesticides tested had significant larvicidal activity against both young and older instars of CLM compared to the water-treated control. Of the botanical pesticides tested, Neemazal was the most larvicidal botanical, causing mortalities ranging from 84 to 100%, the least effective was the P. anisum extract, but at high concentrations this extract still caused significant mortality. Results from field trials also revealed that the botanical pesticides had larvicidal activity against CLM. Neemazal was the most larvicidal botanical, followed by Greeneem oil then by O. onites and finally by P. anisum. Our overall results suggest that all the botanical pesticides tested are promising as larvicides against CLM, and may provide an alternative control method that is more compatible with Integrated Pest Management programs than the use of synthetic chemical pesticides.     

Antifeedant activity and toxicity of leaf extracts from <Emphasis Type="Italic">Porteresia coarctata</Emphasis> Takeoka and their effects on the physiology of <Emphasis Type="Italic">Spodoptera litura</Emphasis> (F.)

Antifeeding and toxic effects of chemical extracts from Porteresia coarctata Takeoka on the insect pest Spodoptera litura (F.) were investigated in the laboratory. Hexane extracts of P. coarctata leaves were re-dissolved in dimethyl sulfoxide and applied in water to leaves of Ricinus communis L. (castor). A concentration of 1,000 and 2,000 ppm extract exhibited significant antifeeding and toxic effects to third instar larvae when compared to the same concentration of dimethyl sulfoxide in water as control. One day after feeding on extract-treated castor leaves, the mortality of S. litura larvae was 50%. Mortality increased to 95% after 11 days at a dosage of 2,000 ppm. Compared to the control, third instar larvae fed on castor leaves treated with P. coarctata leaf extract at different concentrations showed significant reduction in protein and DNA content in the fat body and midgut tissues. Results demonstrate the insecticidal and antifeedant properties of P. coarctata leaf extract against the generalist pest S. litura leading to biochemical changes in the insect body. Thus, P. coarctata contains phytochemicals, and the extract, in crude and pure form, has potential as a botanical insecticide in alternative control strategies against Lepidoptera pests.     

青钱柳叶提取物对Caco-2细胞二糖酶活性的抑制作用

采用Caco-2细胞模型,分析了青钱柳Cyclocarya paliurus叶水提物、醇提后的水提物、95%醇提物、乙酸乙酯萃取物和正丁醇萃取物5种不同提取物对Caco-2细胞活力的影响及对Caco-2细胞上麦芽糖酶、蔗糖酶、乳糖酶3种二糖酶活性的抑制作用。结果表明,5种不同提取物中除95%醇提物对Caco-2细胞活力产生一定影响外,其余4种提取物对Caco-2细胞基本无毒性,在200 mg·L^-1浓度提取物范围内培养24～72 h后细胞仍能保持较高活力;对3种二糖酶活性抑制作用效果最好的为醇提后的水提物,尤其是对蔗糖酶和乳糖酶的抑制作用更为明显,最高的抑制率分别达到76.35%和60.13%,其次为乙酸乙酯萃取物,对乳糖酶的抑制率最高达54.41%。从青钱柳叶不同方法提取物的制备流程说明多糖类或中等极性的黄酮甙类有可能是青钱柳叶中抑制二糖酶活性的主要组成成分。     

Pilot-Versuch zur Bekämpfung von Stechmückenlarven im Freiland mit einem UV-behandelten Präparat von Bacillus thuringiensis var. israelensis

Preparations derived from sporulated cultures ofBacillus thuringiensis var.israelensis were used in a small field trial for control of mosquito larvae (Aedes cantans, Aedes rusticus, Culiseta morsitans). In the test two liquid formulations (suspension) were compared: (1) a native preparation containing living spores and toxic crystals, and (2) a preparation in which the spores have been inactivated to a high degree (99.99%) by ultraviolet rays. The efficacy of both preparations against mosquito larvae showed no difference: doses of 10⁴ to 10⁵ spore equvalents/ml, induced 100% mortality of the target insects. But no harmful effect on non-target organisms (especially water arthropods with exception of Chironomidae larvae) could be observed. To minimize the contamination of surface water with living spores, the use of UV-inactivated preparations ofB. t. var.israelensis is indicated for mosquito control.     

杜仲叶提取物的抑菌活性研究

为了发现新的抑茵材料,对杜仲叶70％(体积分数)乙醇提取物及其分级组分进行了抑菌试验.结果显示:杜仲叶的乙醇和乙酸乙酯提取物对细菌和真茵都有抑制作用,而且乙酸乙酯提取物对黄曲霉和黑曲霉有特殊的抑制特征;正丁醇和水提取物对细菌有抑制作用,但对真菌几乎没有抑制作用;石油醚提取物几乎对细菌和真茵都没有抑制作用.最大抑茵圈直径超过了10 mm,最小抑茵浓度(MIC)在0.25％～3.0％之间.杜仲叶提取物在抑菌活性方面具有一定的热稳定性,抑茵率随时间而逐渐增加,16 h之后基本保持不变.     

核桃楸叶乙醇提取物的抑菌活性及活性成分分析

采用常规提取法浸提核桃楸叶的抑菌活性成分。研究结果表明,核桃楸叶乙醇提取物及其乙酸乙酯萃取相对杨树叶枯病菌和樟子松枯梢病菌有抑菌活性,核桃楸叶乙醇提取物及其乙酸乙酯萃取相对杨树叶枯病菌的最低抑菌质量浓度(MIC)为3.12 g/L,对樟子松枯梢病菌的MIC为6.25 g/L。采用GC-MS分析了核桃楸叶乙醇提取物中乙酸乙酯萃取相经柱层析后集分I和集分II的化学组成和相对含量。分析结果表明,乙酸乙酯萃取相中主要活性成分为相对含量较高的5-羟基-1,4-萘醌(胡桃醌)、D-阿洛糖、5,8-二羟基-1,4-萘醌、1,5-萘二酚、2,3-二氢苯并呋喃、7-甲氧基-1-四氢萘酮、1-萘酚、8-羟基-2-甲氧基-1,4-萘醌和4-甲基-2,6-二羟基喹啉等。     

Ovicidal, larvicidal and anti-ovipositional activities of Bifora radians and other plant extracts on the grape berry moth Paralobesia viteana (Clemens)

Methanol extracts of Bifora radians, Arctium lappa, Humulus lupulus and Xanthium strumarium were tested against the North American grape berry moth, Paralobesia viteana in laboratory and greenhouse assays. Egg hatch was reduced by B. radians and X. strumarium extracts, whereas larval mortality was observed in response to B. radians, X. strumarium and A. lappa. Given the high mortality against egg and larval stages of this pest caused by extracts of B. radians, further studies were performed to determine the dose?Cresponse relationships between extracts of this plant and oviposition and egg hatch of P. viteana. There was a significant reduction in egglaying and egg hatch with increasing extract concentration, with 0.1% extracts providing 80% mortality and 1% extracts causing more than 90% control. This study demonstrates the potential of this plant extract for crop protection against a key pest of grapes and suggests that additional crop pests and field tests should be pursued to determine the efficacy of B. radians extracts as a biopesticide.     

Larvicidal activity of Solanum villosum Mill (Solanaceae: Solanales) leaves to Anopheles subpictus Grassi (Diptera: Culicidae) with effect on non-target Chironomus circumdatus Kieffer (Diptera: Chironomidae)

Chloroform-methanol extract of mature leaves from Solanum villosum Mill (Solanaceae: Solanales) was investigated to establish its biocontrol potentiality under laboratory condition against larval forms of Anopheles subpictus Grassi (Diptera: Culicidae), the vector of human malaria. All the graded concentrations (30, 50, 100 and 200 ppm) showed significant (P < 0.05) larval mortality and results of regression equations revealed that the mortality rates were positively correlated with the concentrations of the extract (R ² close to 1). LC₅₀ values for all instars were between 24.20 and 33.73 ppm after 24 h and between 23.47 and 30.63 ppm after 48 h of exposure period. Significant changes in the larval mortality (F < 0.05) was also recorded between instars during single “ANOVA” analysis. This extract also demonstrated no toxicity to larvae of Chironomus circumdatus Kieffer (Diptera: Chironomidae) which were found to be present as most common non-target dipteran insect in the habitats of A. subpictus. Qualitative and chromatographic analysis of the solvent extract revealed the presence of carbohydrates, saponins, terpenoids, volatile oil, steroids, phenols and flavonoids as major bioactive phytochemicals.     

桉叶抗氧化物的提取与抗氧化性质研究

以广林9号桉叶粉为材料,通过单因素和正交实验,确定最佳提取条件为50％乙醇、料液比1：20、50℃提取1h;抗氧化稳定性研究表明：光照、空气和温度对提取物抗氧化活性均有较大的影响,而pH值对其影响较小;对酚类物质的含量进行测定,表明提取物中酚类物质的含量与抗氧化效果成正相关;以有机溶剂对上述提取物进行萃取,抗氧化效果为正丁醇萃取物〉乙酸乙酯萃取物〉水萃取物〉石油醚萃取物;然后比较了不同浓度乙醇作为洗脱剂对正丁醇萃取物分离的影响,以50％和70％乙醇洗脱成分活性最强。     

Insecticidal activities and chemical components of alcohol extract from leaves of Rhodendron dauricum L.

The extract from leaves of Rhododendron dauricum L. was extracted with 95% alcohol by common method for studying its insecticidal activities. The chemical components of the alcohol extract and relative contents were analyzed by GC-MS. The insecticidal activities of the alcohol extract were tested on the 2nd?3rd instar larvae of Lymantria dispar L. for five days. Five concentrations of the extract samples were designed as 50, 10, 5, 1, and 0.5 g?L?1. The results show that the alcohol extracts from leaves of R. dauricum exhibited insecticidal activities against larvae of L. dispar. The corrected mortality of larvae of L. dispar for was over 50% for both contact toxicity and stomach toxicity at the extract concentration of ≥ 5 g·L?1 after five days of application. The insecticidal activity in contact toxicity is more effect than stomach toxicity for the alcohol extract. Twenty compounds, with total GC relative contents of 93.81% in the alcohol extract from leaves of R. dauricum were identified. The main chemical components in the extract are: (1) 4,5-Dihydro-5-oxo-3-(p-tolyl) isoxazole, with a relative content of 40.03%; (2) 1,3-Benzenediol, 5-methyl-2-(3,7,11-trimethyl-2,6,10- dodecatrienyl)-, (E,E)-, the relative content 18.27%; (3) 3,6-Diphenyl- 1,2,3,4,5,6,7,8-octahydro-1,8-acridinedione, the relative content 3.89%; (4) 6H-[1,2,4]Triazolo[1,5-a]indole, 4a,5,7,8,8a,9-hexahydro-9- methylene-, the relative content 2.99%; (5) 7-Amino-4-methyl-1,8- naphthyridin-2-ol, the relative content 2.64%; (6) 4-Methyl-2,6- dihydroxyquinoline, the relative content 2.63%; (7) 2,4,6- Triaminoquinazoline, the relative content 2.27%; (8) 2(1H)-Quinolinone, 4-hydroxy-1-methyl-, the relative content 2.02%.     

Comparative study of organic solvent-soluble and water-soluble lipophilic extractives from wheat straw 2: spectroscopic and thermal analysis

As a continuing study of six organic solventsoluble lipophilic extractives and one water-soluble lipophilic extract from wheat straw, seven extracts were further compared using Fourier transform-infrared (FT-IR) analysis,¹H and¹³C nuclear magnetic resonance (NMR) spectroscopy, and thermal analysis. In the FT-IR spectra of two-thirds chloroform/one-third methanol, methyltertbutyl ether (MTBE), hexane, petroleum ether, and dichloromethane extracts, a strong band at 1746cm^–1 is indicative of the ester carbonyl of triglycerides or steryl esters or waxes, whereas the occurrence of carboxylic carbonyl of free fatty acids or resin acids at 1712–1719 cm^–1 is verified in the spectra of two-thirds toluene/one-third ethanol and hot water extracts. Signals at 187.9,178.4, and 173.3 ppm in the¹³C NMR spectrum of MTBE extract correspond to carbonyl groups of resin acids, fatty acids, and fatty acid/steryl esters, respectively. All the extractives were to varying degrees thermally unstable at a temperature of about 200°C, and the melting temperature occurred at about 54°C.