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1.
Cheese wood, Alstonia boonei De Wild stem bark was extracted with five different solvents namely: methanol, ethanol, acetone, petroleum ether and n-hexane. The extracts were tested for insecticidal activity on cowpea bruchid, Callosobruchus maculatus (Fab.). Adult mortality and adult emergence of the insects were investigated. Oviposition deterrences using dual-choice and multiple-choice tests were also investigated as well as percentage damage and weight loss at temperature of 28?±?2?°C and 75?±?5% relative humidity. Results showed that at the rate of 2% extract per 20?g of cowpea seeds, methanol, petroleum ether and n-hexane extracts caused 100% mortality of adult cowpea bruchid after four?days of post treatment. When the bruchid had choice of oviposition substrate, they laid significantly (p?<?0.05) fewer eggs on cowpea seeds treated with extracts compared to untreated seeds. There was no adult emergence in seeds treated with methanol, ethanol, petroleum ether and n-hexane extracts and 100% reduction in F1 progeny was recorded compared with untreated that had 81.86% adults emergence and 0% reduction in F1 progeny. The results obtained from this study revealed that methanol, ethanol, acetone, petroleum ether and n-hexane extracts of A. boonei stem bark were effective in controlling C. maculatus and could serve as an alternative to synthetic insecticides for the protection of stored cowpeas against bruchids.  相似文献   

2.
为了筛选分离入侵植物猫爪藤的细胞毒活性成分,采用MTT法以75%乙醇提取物的不同组分分别处理人肝癌细胞SMMC7721、Bel7402和正常肝细胞Chang Liver,对他们的体外增殖抑制率进行了研究。结果表明,总醇提物的氯仿组分对肝癌细胞表现出明显的体外增殖抑制作用,其次是石油醚组分。从氯仿萃取组分中分离出具有更强细胞毒活性的成分熊果酸。因此,入侵植物猫爪藤具有体外细胞毒活性,熊果酸是其体外细胞毒活性的主要成分之一。  相似文献   

3.
Females of the almond seed wasp,Eurytoma amygdali Enderlein (Hymenoptera, Eurytomidae), responded in an olfactometer positively to odours from almond flowers and unripe fruits, but not to almond leaf odours and odours from flowers and unripe fruits of certain other nonhostPrunus species. Males responded to none of these odours. Extracts of undamaged unripe almond fruits (using ethanol, methanol, acetone, hexane, dichloromethane, or petroleum ether) stimulated female aggregation on glass surfaces treated with these extracts; in addition, certain fruit extracts (ethanol, methanol, or acetone) stimulated oviposition. Extracts of undamaged almond leaves (ethanol, methanol, or acetone) and flowers (ethanol or methanol) also stimulated female aggregation and oviposition. Aggregation and oviposition in response to an ethanol extract of almond fruits was intense in females aged 5 to 14 days and from 12∶00 to 18∶00h (photophase between 06∶00 and 20∶00). Certain almond fruit (ethanol, methanol, acetone or hexane) and flower extracts (ethanol or methanol) also provoked female response in the olfactometer. The results strongly suggest that certain chemical stimuli emanating from parts of the almond tree play a major role in host selection and oviposition. Some of the extracts tested may be a good source for the isolation, identification and synthesis of compounds stimulating attraction, aggregation and oviposition in nature. *** DIRECT SUPPORT *** A3414024 00003  相似文献   

4.
The larvicidal activity of leaf and bark extracts of Eucalyptus camaldulensis and Eucalyptus citriodora on juveniles of Culex quinquefasciatus was determined. Larvae were successfully bred in the laboratory to obtain a “pure” colony. One hundred and sixty‐two batches of 25 larvae each were treated with 3.90, 15.63, 62.50, 250 and 1000 mg/L of plant extract in three replicates, for 24 h to record mortality and for up to 96 h to record feeding and fecundity. There was an increase in percentage mortality with increase in concentration of the petroleum ether plant extracts. There was a statistically significant difference (P < 0.05) between extracts used in the bioassay and mortality of larvae, but there was no significant difference (P > 0.05) between the two plant species. Statistical analysis of average mortality figures using Probit analysis for the leaf extracts of E. citriodora and E. camaldulensis, respectively, had LC50 of 245.47 (26.89 ± 10.13 [SE]) and 316.23 (22.89 ± 8.95) for the crude extracts; 97.72 (44.95 ± 12.89) and 223.87 (29.17 ± 9.56) for the petroleum ether extracts; and 162.18 (30.7 ± 11.16) and 257.04 (26.47 ± 9.28) for the methanol extracts. The bark extracts of E. citriodora and E. camaldulensis, respectively, had LC50 of 251.19 (27.78 ± 8.39) and 398.11 (20.7 ± 7.17) for methanol; and 302.0 (21.56 ± 8.11) and 630.96 (13.56 ± 6.4) for hexane. Both plant species showed anti‐feeding properties against larvae of Culex quinquefasciatus.  相似文献   

5.
Abstract

The potency of Piper nigrum seed and leaf, Aframomum meleguata seed and Ageratum conyzoides leaf extracts in the control of cassava tuber rot caused by Rhizopus oryzae was investigated. Water, ethanol and petroleum ether were used as extracting solvents. These extracts were fungitoxic both in vitro and in vivo against the test pathogen. P. nigrum seed extracts were the best followed by those of A. meleguata seed, A. conyzoides leaf and then P. nigrum leaf. The extracts were more effective in controlling rot development in unwounded than wounded tubers especially when they were applied before inoculation with the test pathogen. Ethanol extracts gave the highest growth inhibition in vivo followed by water and the petroleum ether extract whereas water extracts showed marked superiority over the extracting solvents in checking rot development in cassava tuber. Water and ethanol extracts of P. nigrum seed and leaf, A. meleguata seed and A. conyzoides leaf could be used as pesticide of plant origin in the control of R. oryzae causing cassava tuber rot in storage.  相似文献   

6.
Six different solvents namely: methanol, ethanol, water, acetone, pet-ether or n-hexane was used to extract the essential oils from cashew kernel. The extracted oils were evaluated on Sitophilus zeamais (Motschulsky 1855) for mortality, oviposition and adult emergence effects. The long-term storage and water absorption capacity of the treated maize grains was also investigated. Results showed that the steam distillate was most lethal on S. zeamais. The least potent extracts on S. zeamais were those extracted with methanol and ethanol. The extracts drastically reduced oviposition in S. zeamais. Maize grains treated with steam distillate extract had the lowest water absorption capacity, while the highest water absorption capacity was obtained in grains treated with ethanol and methanol. Extracts of steam distillate, n-hexane, petroleum ether and acetone completely prevented infestation and subsequence damage of the treated maize grains for a period of three months. In the grains treated with the methanol and ethanol extracts, damage of 28.61% and 6.24%, respectively were obtained. The results obtained reveal that extracts of cashew kernel are effective in controlling S. zeamais and could serve as an alternative to synthetic insecticides.  相似文献   

7.
侧柏乙醇提取物对21种植物病原真菌的抑菌活性   总被引:8,自引:1,他引:7  
采用菌丝生长速率法测定了侧柏(Platycladus orientalis)叶、小枝、球果和种子4个不同部位乙醇提取物对21种植物病原真菌的抑菌活性。结果显示:(1)在供试浓度为50g/L(相当于干样)时,侧柏各部位乙醇提取物对4种供试植物病原真菌均具有较好抑制作用,其中侧柏叶提取物的抑菌效果最好,对供试葡萄白腐病菌(Conio-thyrium diplodiella)、葡萄黑痘病菌(Elsinoe ampelina)、番茄绵腐病菌(Phytophthora melongenae)和青霉病菌(Penicilliu mexpansum)的EC50分别为:5.424、3.186、8.913和19.000g/L。(2)侧柏叶乙醇提取物的石油醚萃取物和乙酸乙酯萃取物抑菌活性均较好,在供试浓度为0.5g/L时,石油醚萃取物对苹果腐烂病菌(Valsa mali)和葡萄黑痘病菌(E.ampelina)的抑菌率分别为80.35%和60.23%;乙酸乙酯萃取物对以上2种植物病原菌的抑菌率分别为81.88%和64.06%。结果表明:侧柏叶、小枝、球果和种子乙醇提取物均具有一定抑菌活性,叶乙醇提取物的活性最好,活性成分主要集中在石油醚萃取物和乙酸乙酯萃取物中。  相似文献   

8.
Longevity and fecundity of female wasps are two decisive factors for the effectiveness of parasitoid species as biological control agents. Accessibility and suitability of nutrient sources determine parasitoid survival and reproduction. Host, nectar and honeydew feeding are frequent adult parasitoid behaviors to cover nutritional needs. Here we postulate that especially parasitoid species of endophytic herbivores might use plant tissue as a nutrient source that becomes accessible upon herbivory. We investigated the influence of plant consumption and host feeding on longevity and fecundity of Hyssopus pallidus, a gregarious ecto-parasitoid of caterpillars of the codling moth that feed inside apple fruits. Longevity of unmated and mated ovipositing female parasitoids was highest in treatments with fruit pulp. While longevity in this treatment was not significantly different from that with honey, it was significantly higher than in treatments without food, with water or with a host alone.Reproduction was significantly increased by these sugar-rich nutrient sources compared to the control with a host alone. In contrast, host feeding did not yield any significant contribution to longevity and fecundity in a series of bioassays with different host–parasitoid ratios and with differently aged and sized hosts, compared to controls without food.We conclude that in this synovigenic species host feeding does not contribute to longevity and fecundity, but females can increase survival and reproduction in the field relying solely on the plant tissue damaged by their host caterpillar.  相似文献   

9.
Petroleum ether, acetone, water and aqueous extract of Pedalium murex L. (Pedalaceae) leaves, root and fruit were tested against fourth instar larvae of the tobacco cutworm, Spodoptera litura (Fabr.) under laboratory conditions using leaf dip method. Larval mortality; larval, pupal and adult periods; pupal weight, pupation and adult emergence; larval and pupal deformities of S. litura were recorded. All the tested solvent extracts of P. murex were effective against S. litura life stages by causing mortality in a dose dependent manner. However, the efficacy was more significant with respect to acetone (leaf and root) and petroleum ether (root) at higher concentrations (0.8%) which leads to 100% larval mortality. The water and aqueous extracts of root caused 86.6 and 88.0% larval mortality respectively at 4% concentration. Among the plant parts tested, root had more importance followed by leaf and fruit. Plant extracts extended the larval, pupal and adult periods; reduced the pupal weight, pupal and adult emergence and caused larval–pupal deformities. Total life time was highly prolonged in acetone extracts of P. murex root. Though all the extracts were found to have insecticide activity, acetone and petroleum ether extracts of P. murex root can be used as an effective alternative to modern synthetic insecticides. Bioactive principles from these extracts can be isolated, identified and integrated in S. litura management.  相似文献   

10.
Abstract

Aqueous extracts of 46 plants belonging to 32 different families of the plant kingdom were screened for antifungal activity against eight important species of Fusarium viz., Fusarium equiseti, F. moniliforme, F. semitectum, F. graminearum, F. oxysporum, F. proliferatum, F. solani and F. lateritium. The test fungi were isolated from maize, paddy and sorghum seeds collected from Mysore district, Mysore, India. Among the several plants screened only 12 plants have recorded significant antifungal activity. The antifungal activity of aqueous extracts varied among the test pathogens and was compared with that of the synthetic fungicides Blitox, Captan, Dithane M-45 and Thiram. F. proliferatum, which showed high susceptibility for the aqueous extracts, was tested using different solvent extracts viz., petroleum ether, benzene, chloroform, methanol and ethanol extracts of all the 12 plants. The results revealed that these plants could be exploited for ecofriendly management of the diseases caused by the test fungal pathogens and seed biodeterioration during storage.  相似文献   

11.
Control of the widely distributed pest Liriomyza huidobrensis, is complicated due to the protected habit of the leafmining larvae, and their resistance to insecticides. The effects of Melia azedarach, (Meliaceae) fruit extracts against adults and larvae of L. huidobrensis, were investigated. In the laboratory, leaves of Cucurbita, sp. infested with first and third instar larvae were treated with different extract solutions. Larval and pupal survival, as well as wing‐spread of adults, were ssessed. Female adult behaviour towards the extract was also analysed in terms of number of feeding punctures and number of offspring left on treated/untreated leaves. In the field, an infested Vicia faba, crop was sprayed four times at weekly intervals with plant extract, water, and a blank solution. The number of adult leafminers and parasitoids emerging from sampled leaves from each treatment were compared. The laboratory tests showed translaminar action of the extracts, which negatively affected leafminer pupal survival, while body size was not affected. The extracts also deterred feeding by adult females and may also have caused reduction in oviposition rates. All solutions and concentrations tested had similar effects. In the field, extract effects were consistent with those from laboratory trials, number of pupae and pupal survival being lower on treated plants. Percentage parasitism was not affected by plant extract treatment, suggesting a selective activity.  相似文献   

12.
The current research has been designed to assess the phytochemical composition, antioxidant and antidiabetic properties of Hopea parviflora, sequentially extracted with petroleum ether, chloroform, ethyl acetate, ethanol and methanol. All the five extracts were tested for qualitative and quantitative phytochemicals. DPPH, Superoxide, FRAP, ABTS and metal chelating antioxidant activities were evaluated. Antidiabetic potentials of all the five extracts were tested using standard in vitro α- amylase and α - glycosidase inhibition assays. Qualitative phytochemical screening showed the presence of alkaloids in all the extracts except petroleum ether and ethyl acetate. Steroids were present in the petroleum ether, ethyl acetate and chloroform extracts whereas glycosides were present in all the extracts, except ethanol. The total phenol, flavonoid, tannin and saponins contents varied from solvent to solvent, with the highest values being 18.9, 18.2, 0.98 and 39.9 mg/mL, respectively. Methanolic extract showed the highest antioxidant activities in DPPH, FRAP and superoxide assays. Moreover, effective results were observed for the ethanol and ethyl acetate extracts in the ABTS and metal chelating assays. The methanolic extract showed potential antidiabetic activities with the IC50 values of 230.2 and 308.2 μg/mL in α- amylase and α -glycosidase inhibition assays, respectively.  相似文献   

13.
The growing demand of medicinal plants is posing a major threat to biodiversity conservation. Sclerocarya birrea and Harpephyllum caffrum (Anacardiaceae) are traditionally used to treat numerous ailments increasing their susceptibility to overexploitation. The aim of the study was to evaluate the medicinal efficacy of renewable aerial parts of the plants using in vitro assays, thus providing a conservation measure by plant part substitution. Plant samples were sequentially extracted with petroleum ether, dichloromethane and 80% ethanol, sonicated on ice and concentrated under vacuum. Antimicrobial activities were determined by the minimum inhibition concentration (MIC) using the micro-dilution assay. The ability of extracts to inhibit COX-1 and COX-2 enzymes was used to evaluate anti-inflammatory activity. Ethanolic extracts of S. birrea and H. caffrum exhibited high antibacterial activity (MIC < 1.0 mg/ml). S. birrea twig extract was the most active with a total activity of 1609.1 ml/g against Bacillus subtilis and an MIC of 0.098 mg/ml. Petroleum ether and dichloromethane extracts exhibited high COX-1 (90.7–99.8%) and COX-2 (69–92.6%) enzyme inhibition at a concentration of 250 μg/ml. The extracts of S. birrea and H. caffrum exhibited high antimicrobial and anti-inflammatory properties. Based on these results, plant part substitution can be a practical conservation strategy for the two species.  相似文献   

14.
六种藜科植物提取物对植物病原菌的抑制活性   总被引:1,自引:0,他引:1  
研究了角果藜( Ceratocarpus arenarius)、盐穗木( Halostachys caspica)、里海盐爪爪( Kalidium caspicum) 、叉毛蓬( Petrosimonia sibirica )、盐角草( Salicornia europaea )和小叶碱蓬 ( Suaeda microphylla )等六种新疆藜科植物提取物及其不同极性萃取部分对根癌土壤杆菌(Agrobacterium tumefaciens )、黄瓜角斑病菌(P Pseudomonas lachrymarts)、番茄疮痂病菌( Xanthomonas vesicatoria ) 等植物病原细菌以及杨树溃疡病菌( Botryosphaeria dothidea )、棉花枯萎病菌(Fusarium oxysporum f. sp. vasinfectum )、稻纹枯病菌(Rhizoctonia solani)等病原真菌的抑制活性。结果显示角果藜、叉毛蓬和盐角草乙醇粗提物表现出一定抗细菌活性,其中以叉毛蓬和盐角草提取物对黄瓜角斑病菌的抑制活性最强。多数植物提取物及其不同极性萃取部分对杨树溃疡病菌表现出强的抑制活性。抗真菌活性成分主要存在于供试植物的石油醚、氯仿和正丁醇萃取部分中,提示活性成分为极性中等的化合物。角果藜和盐角草乙醇粗提物及其不同极性萃取部分对供试真菌有较好的抑制活性。  相似文献   

15.
The response of beetles to various host extracts obtained by different solvents of a wide range of polarity have been examined by a bioassay method. Ether as a low-polar solvent was more effective than ethanol. The effectiveness of the ethanol decreases with an increase in its polarity.Extracts from infested hosts elicited a greater response than those from uninfested hosts. This has been demonstrated by ether and ethanol extracts, with plum and apricot hosts. Ether extract from an infested host was about four times more active than that from an uninfested host. These results were in accordance with those obtained in situ in which beetles were attracted to infested twigs more strongly than to uninfested twigs. An extract from a non-host plant (orange) was ineffective and its response value resembled that of untreated control.There is a strong indication that after an initial attack, beetle secretions together with plant material are responsible for a mass attraction of the beetles in the field.
Résumé La réaction de ce Scolyte envers des extraits de plantes-hôtes obtenus au moyen de solvants de polarité très différente a été examinée. L'éther a été plus efficace que l'éthanol dont l'efficacité décroît inversement à sa polarité.Les extraits d'hôtes attaqués par l'insecte provoquaient une réaction plus vive que ceux d'hôtes non infestés. Ceci fut démontré avec des extraits éthériques et éthanoliques de prunier et d'abricotier.Les extraits éthériques d'hôtes attaqués étaient environ quatre fois plus actifs que ceux d'hôtes non infestés. Les résultats s'accordent avec ceux obtenus in situ, l'insecte étant attiré plus fortement par des branches infestées que par celles non attaquées.D'apr`es nos résultats il semble que dans le verger la sécrétion du scolyte associée à la matière végétale provoquent ensemble l'attaque massive.


Contribution from The Volcani Institute of Agricultural Research, Bet Dagan, Israel. 1971 series; No. 1898 E.  相似文献   

16.
The effects of extracts (petroleum ether, ethanol, water) of Ajuga reptans on the moult cycle were investigated in the last-larval instar of Periplaneta americana. Petroleum ether, as well as ethanol extracts, delay the onset of the imaginal moult. At the same time, when 100% of the control animals had moulted, only 30% of the treated animals had moulted. Water extract shows only a slight effect. In animals treated with an ethanol extract, a gradual involution of the cytoplasm of prothoracic gland cells is seen, depending on the duration of the treatment. Consequently the portion of intracellular spaces significantly increases. As seen by radioimmunoassay, at any time after the last-larval moult, ecdysteroid production by the prothoracic glands from animals treated with ethanolic Ajuga extracts stays at the low level of the intermoult animals. The fact that the secretion of the ecdysial glands remains at the low intermoult level suggests (along with other contributing facts) that there is an inhibitory influence on the gland rather than a cytotoxic effect.  相似文献   

17.
Hyoscyamus species is one of the four plants used in Ayurveda for the treatment of Parkinson’s disease (PD). Since Hyoscyamus niger was found to contain negligible levels of L-DOPA, we evaluated neuroprotective potential, if any, of characterized petroleum ether and aqueous methanol extracts of its seeds in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD in mice. Air dried authenticated H. niger seeds were sequentially extracted using petroleum ether and aqueous methanol and were characterized employing HPLC-electrochemistry and LCMS. Parkinsonian mice were treated daily twice with the extracts (125–500 mg/kg, p.o.) for two days and motor functions and striatal dopamine levels were assayed. Administration of the aqueous methanol extract (containing 0.03% w/w of L-DOPA), but not petroleum ether extract, significantly attenuated motor disabilities (akinesia, catalepsy and reduced swim score) and striatal dopamine loss in MPTP treated mice. Since the extract caused significant inhibition of monoamine oxidase activity and attenuated 1-methyl-4-phenyl pyridinium (MPP+)-induced hydroxyl radical (·OH) generation in isolated mitochondria, it is possible that the methanolic extract of Hyoscyamus niger seeds protects against parkinsonism in mice by means of its ability to inhibit increased ·OH generated in the mitochondria.  相似文献   

18.
Abstract

Investigations were carried out on the pesticidal potentials of seed of Piper nigrum and Aframomum melegueta and leaves of P. nigrum and Ageratum conyzoides using water, ethanol and petroleum ether as extracting solvents. Leaf extracts of P. nigrum and A. conyzoides and seed extracts of A. melegueta and P. nigrum significantly inhibited the mycelial radial growth and mycelial biomass of Botryodiplodia acerina in vitro. Ethanol extracts recorded the highest growth inhibition followed by water and petroleum ether extracts. The extracts checked the rot development in unwounded cassava tubers especially when they were applied before spray-inoculating with B. acerina. Water leaf extracts of P. nigrum and A. conyzoides and seed extracts of A. melegueta and P. nigrum could be a potent source of natural pesticide for managing post-harvest rot of cassava tubers caused by B. acerina.  相似文献   

19.
The study was implemented to actuate the qualitative and quantitative phyto constituents of Iresine herbstii extracts and its antiviral efficacy against avian ND virus. Among four tested solvents, the ethanolic extract of Iresine herbstii revealed the presence of highest quantity of all tested phytochemicals while petroleum ether extract showed the least. Folin-Ciocalteu method assessed the range of TPC extended from 81.01 ± 0.67 to 126.35 ± 0.45 µg GAE/mg. Acetonic extract showed the highest amount among all extracts and petroleum ether possessed the lower quantity. TFC ranged from 54.37 ± 0.45 to 88.12 ± 0.26 µg QE/mg followed by colorimetric method. From all extract ethanolic extract showed highest quantity and petroleum ether revealed the lower. HPLC analysis of ethanolic extract of I. herbstii confesses the presence six bioactive components by using the HP5-MS column. To check the antiviral potential of plants, different prepared treatments of plant extract and live virus were inoculated at 9 days old SPF embryonated chicken eggs. Results exposed that all plant extracts produce antiviral activity against NDV in ovo according to their potential and phytochemical profile. The highest survival rate was observed in the ethanolic extract at 400 µg/mL and acetonic extract at 300 µg/mL as it controls the NDV activity completely, evidence of absence of embryo death and HA titre. Dichloromethane and petroleum ether could not inhibit the virus completely. 600 µg/mL concentration was proved as toxic in all extracts except petroleum ether extract which showed a dose dependent pattern.  相似文献   

20.
Egg masses laid by Spodoptera littoralis mated female moths were extracted by petroleum ether (PE), ethanol (E) and Ringer's solution (RS). Egg-wash extracts were evaporated and the weights of crude materials were obtained. Different aqueous concentrations were made. The amount of extracted material increased as the weight of eggs used increased and vice versa. Coating Nerium oleander leaves with aqueous egg-wash extracts prepared from S. littoralis egg-masses deterred the mated conspecific female moths from ovipositing their eggs on treated leaves, as well as causing a decrease in the total number of deposited eggs per female during the moth's life span. The highest deterrent effect on conspecific female moths to oviposit their eggs was obtained after treatment of N. oleander leaves with PE or E egg-wash extract. The deterrent effects of the tested egg-wash extracts was concentration dependant; an increase in the concentration of any extract caused an obvious decrease in the number of deposited egg-masses and the total number of laid eggs on the treated N. oleander leaves.  相似文献   

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