Insect growth regulatory activity of some extracts and compounds from Parthenium argentatum on fall armyworm Spodoptera frugiperda

The methanolic extract from aerial parts of Parthenium argentatum, afforded argentatin A and B. These compounds were evaluated for their effect on the fall armyworm (Spodoptera frugiperda). Toosendanin, a commercial insecticide derived from Melia azedarach was used as positive control. When tested for activity, using neonate larvae into the no-choice artificial diet bioassays, argentatin A, argentatin B and methanol extract caused significant growth inhibitory activity with GC50 of 17.8, 36.1 and 6.4 ppm at 7 days, respectively, and increased the development time of surviving larvae in a concentration-dependent manner with RGI values of 0.40, 0.60 and 0.26, at 25.0, 25.0 and 5.0 ppm, respectively. In addition, it was possible to observe in most of the treated groups a significant delay in the time of pupation, adult emergence and deformities. Acute toxicity against adults of S. frugiperda was also found, MeOH extract had the most potent activity with LD50 value of 3.10 ppm. In addition, MeOH extract and argentatin A caused acetylcholinesterase inhibition of 93.7% and 90.0%, at 5.0 and 50.0 ppm, respectively; whereas argentatin B had only slight inhibitory activity. Therefore, the MeOH extract was identified as insecticidal extract from P. argentatum with activity at concentrations above 15.0 ppm.     

Sterculia guttata seeds extractives--an effective mosquito larvicide

The larvicidal activity of ethanol, chloroform and hexane soxhlet extracts obtained from S. guttata seeds was investigated against the IVth instar larvae of Dengue fever vector, Aedes aegypti and filarial vector, Culex quinquefasciatus. All extracts including fractions of ethanol extract exhibited 100% larval kill within 24 hr exposure period at 500 ppm concentration. Fraction A1 of ethanol was found to be most promising; its LC50 was 21.552 and 35.520 ppm against C. quinquefasciatus and A. aegypti respectively. Naturally occurring S. guttata seed derived fractions merit further study as potential mosquito larval control agents or lead compounds.     

Red Mexican grapefruit: a novel source for bioactive limonoids and their antioxidant activity

Citrus limonoids have shown to inhibit the growth of cancer in colon, lung, mouth, stomach and breast in animal and cell culture studies. For the first time in the present study, an attempt has been made to isolate antioxidant fractions and five limonoids from red Mexican grapefruit seeds. Defatted seed powder was successively extracted with hexane, ethyl acetate (EtOAc), acetone, methanol (MeOH) and MeOH/water and the extracts were concentrated under vacuum. Radical scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and total phenolic content were also measured for comparison with the antioxidant capacity in the phosphomolybdenum method for the above extracts. Acetone and MeOH extracts, respectively, showed the highest (85.7%) and lowest (53.3%) radical scavenging activity, at 500 ppm. The total phenolic contents were found to be highest in the acetone extract (15.94%) followed by the MeOH extract (5.92%), ethyl acetate extract (5.54%) and water extract (5.26%). Antioxidant capacity of the extracts as equivalents to ascorbic acid (micromol/g of the extract) was in the order, EtOAc extract > acetone extract > water extract > methanol extract. Furthermore, the EtOAC and acetone extracts were loaded onto silica gel columns to obtain four limonoid aglycons. MeOH fraction was loaded onto a dowex-50 and sepabeads resin column to obtain a limonoid glucoside. The purity of the isolated five compounds was analyzed by HPLC using a C18 column and UV detection at 210 nm. Finally, the structures of the compounds were identified as obacunone, nomilin, limonin, deacetylnomilin (DAN) and limonin-17-beta-D-glucopyranoside (LG) using 1H and 13C NMR studies.     

Insect growth regulatory effects of some extracts and sterols from Myrtillocactus geometrizans (Cactaceae) against Spodoptera frugiperda and Tenebrio molitor

A methanol extract from the roots and aerial parts of Myrtillocactus geometrizans (Cactaceae) yielded peniocerol 1, macdougallin 2, and chichipegenin 3. The natural products 1, 2 their mixtures, MeOH and CH(2)Cl(2) extracts showed insecticidal and insect growth regulatory activity against fall armyworm [Spodoptera frugiperda J. E. Smith (Lepidoptera: Noctuidae)], an important insect pest of corn, and [Tenebrio molitor (Coleoptera)], a pest of stored grains in Mexico. The most active compounds were 1, 2, and a mixture (M(2)) of 1 and 2 (6:4). All these extracts, compounds and the mixture had insect growth regulating (IGR) activity between 5.0 and 50.0 ppm and insecticidal effects between 50 and 300 ppm in diets. The extracts were insecticidal to larvae, with lethal doses between 100 and 200 ppm. These compounds appear to have selective effects on the pre-emergence metabolism of Coleoptera, because in all treatments of the larvae of T. molitor, pupation were shortened and this process show precociousness in relation to controls. In contrast to S. frugiperda larvae, onset of pupation was noticeably delayed. Emergence in both cases was drastically diminished. In both pupae and in the few adults that were able to emerge, many deformations were observed. The results of these assays indicated that the compounds were more active than other known natural insect growth inhibitors such as gedunin and methanol extracts of Cedrela salvadorensis and Yucca periculosa. Peniocerol, macdougallin and chichipegenin, as well as mixtures of these substances, may be useful as natural insecticidal agents.     

Antimicrobial activity of organic extracts isolated from Aplysina fistularis (Demospongiae: Aplysinidae)

Organic extracts of the sponge Aplysina fistularis (Pallas 1766) were tested for antimicrobial activity against Gram positive bacteria (Staphylococcus aureus) and Gram negative bacteria (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa). The minimal inhibitory concentration (MIC) and toxic activity of extract were determined. Susceptibility trials of organic fractions obtained by VLC: Hexane, EtOAc and CHCl3 showed that EtOAc fraction has antibacterial activity against E. coli, while CHCl3 fraction inhibited E. coli and S. aureus growth. The later refractioning of EtOAc fraction and the biodirected assays showed that fractions F12 and F13 of EtOAc/Hex and EtOAc F14 were bioactive against Gram positive and Gram negative bacteria. Only EtOAc/MeOH Sf2 from subfractionig of EtOAc F14 produced inhibition for E. coli and S. aureus. In Sf2 EtOAc/MeOH, MIC was moderate for S. aureus (MIC > 256 g/ml). F4 CHCl3/MeOH produced a high inhibition in S. aureus (MIC = 0.125 g/ml) and for E. coli (MIC > 16 g/ml). F10 CHCl3/MeOH showed a moderate activity against S. aureus (MIC > 128 g/ml) and low activity against E. coli (MIC = 512 g/ml). F10 CHCL3/MeOH did no present toxic activity against Artemia salina. The fractiorts F4 CHCL3/MeOH and Sf2 EtOAc/MeOH were toxic for this organism when the concentration was higher than 100 microg/ml. LC50 in both cases was 548.4 and 243.4 microg/ml respectively. Secondary metabolites of medium polarity obtained from A. fistularis have a wide spectrum of anti bacterial activity. Toxicity analysis suggests that only F10 CHCL3/MeOH has potential as an antimicrobial agent for clinical use.     

Biological Effects of Caesalpinia crista Seed Extracts on Helicoverpa armigera (Lepidoptera: Noctuidae) and Its Predator,Coccinella septumpunctata (Coleoptera: Coccinellidae)

Caesalpinia crista seed extracts were investigated in the laboratory against Helicoverpa armigera (Hubner). The extracts exhibited powerful antifeedant and growth disruption activity. The toxic symptoms of the poisoned larvae included reduction in weight gain and mortality of larvae and pupae, larval-pupal intermediates and malformed adults. Maximum anti-feedance is caused by methanol extract (AI₅₀=0.0186%), followed by hexane extract (0.0212%), ethyl acetate extract (0.0416%), butanol extract (0.0767%) and aqueous extract (0.2199%). The larval mortality ranged from 10.00 to 70.00% in different extracts. The 50% larval growth inhibition recorded at 3DAT was statistically at par by methanol and hexane extract. The percent 150 values for inhibiting normal adult emergence were 0.0287, 0.0325, 0.0485, 0.0977 and 0.0547% for methanol, hexane, ethyl acetate, aqueous and butanol extract. The biosafety evaluation of these extracts carried out against the predator, Coccinella septumpunctata showed no mortality of the adults till nine days after treatment. Though the observation taken at 10 DAT, showed slight mortality of adults by methanol extract at both 5.0 and 1.0% concentration.     

Antiulcerogenic activity of crude extract, fractions and populnoic acid isolated from Austroplenckia populnea (Celastraceae)

Many plant crude extracts and their isolated compounds are the most attractive sources of new drugs and show promising results for the treatment of gastric ulcers. Austroplenckia populnea is commonly known as "marmelinho-do campo, mangabeira-brava, mangabarana and vime" and it has been used in folk medicine as anti-dysenteric and anti-rheumatic. Powdered bark wood (3.25 kg) was macerated with aqueous ethanol (96%) and the extract was concentrated under reduced pressure to yield 406 g of crude hydralcoholic extract. The hydralcoholic extract was suspended in aqueous methanol and partitioned with hexane, chloroform and ethyl acetate (EtOAc) in sequence, yielding 8.0 g, 9.5 g and 98.17 g of crude extracts, respectively. Chromatography of the hexane extract over a silica gel column led to the isolation of the triterpene populnoic acid. The oral administration of hydralcoholic, hexane, chloroform and EtOAc extracts (200 mg/kg) decreased the ulcer lesion index (ULI) by 83.15%, 46.87%, 32.2%, 68.12%, respectively. Oral administration of populnoic acid (100 mg/kg) diminished the ULI by 55.29%. All the obtained results were significant in comparison with the negative control, with exception of the chloroform extract.     

Toxicity and synergism in the feeding deterrence of some coumarins on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae)

The phagodepression activity of five coumarins (= 2H-1-benzopyran-2-ones), 6-hydroxy-7-isoprenyloxycoumarin (1), 6-methoxy-7-isoprenyloxycoumarin (2), 6,7-methylenedioxycoumarin (3), 5-methoxy-6,7-methylenedioxycoumarin (4), and 6-methoxy-7-(2-hydroxyethoxy)coumarin (5), from the Argentine native herb Pterocaulon polystachyum, was tested against Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae. Two analogs, scopoletin (6) and 2-methoxy-2-methyl-3,4,5,6,7,8-hexahydro-3H-chromen-5-one (7), synthesized in our laboratory, were also evaluated for comparison. The compounds were added to an artificial diet at doses ranging from 50 to 200 microg per g of diet. Natural coumarins induced 100% of phagodepression when 200 microg were added per g of diet. Binary equimolar mixtures of the natural coumarins were phagodepressors against S. frugiperda surpassing the expected additive responses, indicating that these compounds can act synergistically against S. frugiperda larvae. Compounds 1 and 3 (non-methoxylated coumarins), and the equimolar mixture of both, displayed the strongest phagodepression. Additionally, 50 microg/g of 1 and 3 incorporated to the larval diet caused 80 and 50% of pupal mortality, respectively, while a 100 microg/g dose of compounds 2, 4, 6, and 7 produced 60, 50, 10, and 80% pupal mortality, respectively. Larval growing rate during the early larval instars was significantly reduced by treatments with the methylenedioxycoumarins 3 and 4. Coincidentally, the larval period duration was significantly increased by the latter compounds.     

THE BIOLOGICAL ACT'IVITIES OF YELLOW AZALEA,RHODODENDRON MOLLE G. DON AGAINST THE VEGETABLE LEAFMINER,LIRIOMYZA SATIVAE (DIPTERA: AGROMYZIDAE) *

Abstract The results of laboratory and greenhouse bioassays indicated that Rhodojaponin‐ III (Abbr. R‐ 1) and extracts of flowers from Rhododendron molle G. Don possessed signficant feeding inhibition and insectcidal properties against the larvae and adults of Liromyzia sativae. Treated with 500 mg/L R‐ III 1 000 mg/L molosul‐tap, and 10 000 mg/L methanol(MeOH) ethyl acetate (EtOAc), CH₂Cl₂, methanol‐water (MeOH‐H₂O) extracts the rates of feeding inhibition were 77. 34 % 74.30 % 82.15 % 77.50 % 67. 33 % 62.85 % against the 2nd instar larvae, and were 67.66% 55.21 % 49.72% 54.26% 46.81 % 38.53% against the 3rd instar larvae, respectively;LC₅₀ values against the 2nd instar larvae were 208.65, 166.05, 2.74 ± 10³,766.72, 5.95 ± 10³, 1.85 ± 10³mg/L, and against 3rd larvae were 300.62, 256.00, 4.33 ±10³, 1.03 ± 10³,9.79 ± 10³, and 2.62± 10³mg/L, respectively. Against the adults, LC₅₀ values of R‐III EtOAc extract and molosultap were 159.07.723.87 and 134.55mgL respectively after treatment for 24 h.     

Efficacy of two tropical plant extracts for the control of mosquitoes

The larvicidal activity of seed and leaf extracts of Calophyllum inophyllum and leaf extract of Rhinacanthus nasutus on the juveniles of Culex quinquefasciatus , Anopheles stephensi and Aedes aegypti was determined. Ethyl acetate (EA) soluble fractions of C. inophyllum and petroleum ether (PE) fraction of R. nasutus extracts showed very high larvicidal activity. Irrespective of the species of the mosquitoes tested, at concentrations ranging from 3.91 to 9.39 ppm, 9.04 to 35.49 ppm and 13.21 to 28.92 ppm of the active fractions of seed and leaf extracts of C. inophyllum and the leaf extract of R. nasutus , respectively, killed 50% of the treated larvae. The fractions also interfered with adult emergence. Exposure of the mosquitoes at any stage of their larval development to less than 0.86, 5.49 and 6.81 ppm of the active fractions of seed and leaf extracts of C. inophyllum and the leaf extract of R. nasutus , respectively, inhibited 50% of the treated larvae from emerging as adults. Experiments under laboratory and semi-field conditions showed that the activity of the extracts persisted for up to 10 days.     

Laboratory and field evaluations of extracts from Rhododendron molle flowers as insect growth regulator to imported cabbage worm, Pieris rapae L. (Lepidoptera:Pieridae)

The insect growth regulating properties of rhodojaponin-III (Abbr. R-III) and ethyl acetate (EtOAc) extract from Rhododendron molle G. Don flowers against imported cabbage worm, Pieris rapae L., were determined under laboratory and field conditions. The values of IC₅₀ (the median of concentration for inhibiting weight increase) for R-III and EtOAc extract were 6.78 p.p.m. and 70.29 p.p.m. against 3rd instar larvae and 13.72 p.p.m. and 346.00 p.p.m. against 5th instar larvae, respectively. R-III and EtOAc extract also could reduce pupating rate, pupal weight, emergence rate and extend the duration of development. Thus development of insects was inhibited significantly and development index decreased. R-III would be superior to toosendanin as insect growth regulator. EtOAc extract 1000 p.p.m. mixture with molosultap 500 p.p.m. could achieve an effective control rate of 87.34% against P. rapae in field trials when adjusted cumulative insect-days were used as index.     

Efficacy of leaves extract of Calotropis procera Ait. (Asclepiadaceae) in controlling Anopheles arabiensis and Culex quinquefasciatus mosquitoes

The present study aimed to investigate, the larvicidal, adult emergence inhibition and oviposition deterrent activity of aqueous leaves extract of Calotropis procera against Anopheles arabiensis and Culex quinquefasciatus as natural mosquito larvicide. The larvicidal activity was monitored against 2nd, 3rd and 4th instar larvae of each mosquito species 24 h post-treatment. Adult emergence inhibition activity was tested by exposing 3rd instar larvae of each mosquito species to different concentrations of extracts (200, 400, 600, 800 and 1000 ppm for An. arabiensis and 100, 200, 300, 400, 500 and 600 ppm for Cx. quinquefasciatus). Probit analysis was used to analyze data from bioassay experiments. The oviposition deterrent activity was tested by using three different concentrations of extracts (1000, 500 and 200 for An. arabiensis, and 1000, 500 and 100 for Cx. quinquefasciatus) that caused high, moderate and low larval mortality in the larvicidal experiment against 3rd instar larvae. It was found that, LC50–LC90 values calculated were 273.53–783.43, 366.44–1018.59 and 454.99–1224.62 ppm for 2nd, 3rd and 4th larval instars, respectively, of An. arabiensis and 187.93–433.51, 218.27–538.27 and 264.85–769.13 ppm for 2nd, 3rd and 4th larval instars, respectively, of Cx. quinquefasciatus. Fifty percent of adult emergence inhibition (EI50) was shown at 277.90 and 183.65 ppm for An. arabiensis and Cx. quinquefasciatus, respectively. The pupal stage was not affected till a concentration of 5000 ppm. The extract showed oviposition deterrence and effective repellence against both mosquito species at different concentrations, with the observation on that maximal eggs were laid in low concentration of extract. These results suggest that the leaves extract of C. procera possess remarkable larvicidal, adult emergence inhibitor, repellent and oviposition deterrent effect against both An. arabiensis and Cx. quinquefasciatus, and might be used as natural biocides for mosquito control.     

飞机草提取物对红脉穗螟的产卵忌避及杀卵活性

为探讨飞机草提取物对红脉穗螟Tirathaba rufivena Walker的防控潜力,采用室内生物测定法,研究了飞机草提取物对红脉穗螟的产卵忌避作用和杀卵活性。结果表明,飞机草乙酸乙酯提取物对红脉穗螟的忌避效果最好,选择性和非选择性忌避率分别为41.85%和46.84%;不同提取物处理红脉穗螟的卵后,均造成卵孵化率降低和初孵幼虫的死亡,其中乙酸乙酯提取物对红脉穗螟卵的影响最大,孵化率和1龄幼虫死亡率分别达到65.89%和40.37%。对飞机草乙酸乙酯提取物进行分级萃取测试各萃取物的活性发现,正己烷萃取物对红脉穗螟的产卵忌避作用和杀卵活性最强。田间试验表明,采用正己烷萃取物稀释50倍和100倍浓度进行田间喷雾,药后15 d对红脉穗螟的种群控制率可达到50%以上。     

Anti-inflammatory activity of Maytenus senegalensis root extracts and of maytenoic acid

Maytenus senegalensis (Lam.) Excell (Celastraceae) root extracts were investigated for their topical anti-inflammatory properties by measuring the inhibition of the Croton oil-induced ear oedema in mice. The highest anti-inflammatory activity was detected in the chloroform extract, which reduced the oedematous response with a potency similar to that of the NSAID reference drug indomethacin (ID(50)=84 and 93 microg/cm(2), respectively). Fractionation of the chloroform and of the hexane extracts led to the isolation of maytenoic acid (1), which exhibited a dose-dependent antiphlogistic effect (ID(50)=0.11 micromol/cm(2)) twice that of indomethacin (ID(50)=0.26 micromol/cm(2)) and only three times lower than that of hydrocortisone (ID(50)=0.04 micromol/cm(2)).     

Screening of Costa Rican Trichilia species for biological activity against the larvae of Spodoptera litura (Lepidoptera: Noctuidae)

Crude methanolic extracts made from the twigs of 39 plant samples from six species of Trichilia collected in Costa Rica, were incorporated into artificial diet and fed to neonate Spodoptera litura larvae. All six plant species tested significantly reduced larval growth after 7 and 10 days. The most active species was T. americana, reducing growth, on average, to 3.9% of control at 1000ppm fresh weight. The least active, on average, was T. glabra. A twig extract of T. americana proved to be more active than wood, bark or leaf extracts, with the twig extract reducing growth of S. litura larvae by 50% (EC(50)) at a dietary concentration of 17.2ppm. When T. americana wood extract was incorporated into artificial diet (10, 25, 50 and 75ppm) and fed to S. litura larvae throughout larval development, growth was slowed and the final weight of pupae and adults was reduced. At higher extract concentrations (50 and 75ppm) larvae entered one or two supernumerary instars before pupation occurred. This was shown to be due to both starvation and to post-ingestive activity of the extract.     

LC-ESI-MS/MS Chemical Characterization,Antioxidant and Antidiabetic Properties of Propolis Extracted with Organic Solvents from Eastern Anatolia Region

Geographic conditions (altitude, climate, and local flora) lead to significant differences in the chemical composition of propolis. Therefore, more research is needed for propolis in different geographical regions. So, the aim of this study was to evaluate the phenolic profile, total phenolic content, antioxidant, and antidiabetic properties of Pülümür propolis from Turkey. Methanol (MeOH), chloroform (CHCl₃), and hexane extracts of propolis were analyzed. LC-ESI-MS/MS analysis of the extracts showed that the most abundant phenolic compound is caffeic acid in the MeOH extract (2943.12±11.12 μg phenolics/g extract), while on the other hand, CHCl₃ extract had the highest total phenolic content (125.75±1.02 mg GAE/g extract). Antioxidant activity was measured using ABTS and DPPH assays, whereas CHCl₃ extract (IC₅₀=6.35±0.11 and 28.84±0.10 μg/mL, respectively) and MeOH extracts (IC₅₀=5.04±0.07 and 28.80±0.09 μg/mL, respectively) showed relatively high antioxidant activity. The MeOH extract showed better antidiabetic activity than the standard compound, acarbose (IC₅₀=0.544 and 0.805 mg/mL, respectively).     

Insecticidal compounds from Tripterygium wilfordii active against Mythimna separata

In the course of screening for novel naturally occurring insecticides from plants, the ethanol extract of the root bark of Tripterygium wilfordii Hook f. was found to show insecticidal activity against larvae of Mythimna separata Walker. Three active compounds were isolated by bioassay-guided fractionation of the extract and characterized as triptolide (1), triptonide (2) and euonine (3) by IR, 1H and 13C NMR and mass spectral analysis. Compounds 1 and 2 showed strong contact activity against 3rd or 5th larvae of M. separata (LD50 1.6 microg/insect for 1, 2.9 microg/insect for 2, no contact activity for 3; LD50 is the lethal dose for 50% mortality). The antifeedant activity against the 3rd larvae of M. separata after a 24-h treatment was demonstrated; 1, 2 and 3 gave EC50 (effective concentration causing 50% antifeedance) values of 0.25, 0.35 and 0.02 mM, respectively. 1 and 2 were inferior to the positive control represented by toosendanin (12a-acetoxyamoorastatin), 3 was superior to toosendanin. For the ingested toxicity against M. separata, 1 had the more potent activity with an KD50 value of 13.5 microg/g (insect body weight) than toosendanin. This is the first report on insecticidal activity of these three compounds.     

黄杜鹃提取物对亚洲玉米螟生物活性的研究

本文报道了闹羊花素 - ( Rhodojaponin- ,简称 R- )和黄杜鹃花乙酸乙酯 ( Et OAc)提取物对亚洲玉米螟 Ostrenia furnacalis Guenée3龄幼虫的拒食、生长抑制和毒杀作用。以饲料柱法测定 R- 和 Et OAc提取物的非选择性拒食作用 AFC50 为 77.0 2和 384 .30 mg/ kg,而以虫重法表示时 ,则分别为15.60和 2 55.4 4 mg/ kg。以 R- 2 0 0 mg/ kg连续饲喂 4天后 ,换为无毒饲料至 15天 ,试虫死亡率为86.67% ,L T50 为 2 .99天 ;以 Et OAc提取物 2 0 0 0 mg/ kg处理时 ,同期的死亡率 66.67% ,LT50 为 3.85天。R- 和 Et OAc提取物的生长抑制中浓度 IC50 分别为 9.30和 39.64mg/ kg。文中还讨论了亚洲玉米螟拒食作用的测定方法和 R- “取食后效应”等作用特点     

Insecticide enhancement with feeding stimulants in corn for western corn rootworm larvae (Coleoptera: Chrysomelidae)

Amounts of the insecticide thiamethoxam required for 50% mortality of western corn rootworm larvae, Diabrotica virgifera virgifera LeConte, were reduced 100-fold when extracts of germinating corn, Zea mays L., were used to entice neonate larvae to feed on it. In behavioral bioassays, neonate rootworm larvae fed vigorously on filter paper disks treated with liquid pressed from corn roots. Moreover, disks treated with an acetone extract of corn (dried and rewetted with water) also elicited strong feeding from larvae. Larvae wandered away from filter paper disks treated with distilled water without feeding. Dilutions of thiamethoxam were tested in the bioassay alone or with corn extract and the efficacy of this insecticide was improved by the addition of the corn extract. For solutions containing 10 ppm thiamethoxam, 95% larval mortality occurred after 30 min of exposure when corn extract was present, but only 38% mortality occurred when the same concentration of insecticide alone (no feeding stimulants) was tested. Larval mortality after 24 h was significantly higher for corn extract-treated disks with 0.01, 0.1, 1, or 10 ppm insecticide than for the same concentrations without corn extract. Thiamethoxam did not deter larval feeding on corn extract, even at the highest concentration of thiamethoxam tested.     

Anthelmintic activity of the stem bark extracts of Berlina grandiflora and one of its active principles, Betulinic acid.

This study examines the anthelmintic activity of a methanol, hexane and ethylacetate extracts of Berlina grandiflora and purified betulinic acid, the major triterpenoid found in the extract. Caenorhabditis elegans, a free living soil nematode was used as in vitro model in the study. A suspension of worms was treated with the extracts. After seven days of incubation activity was assessed in terms of number of worms exhibiting motiliy. The results showed that methanol, hexane and ethylacetate fractions at 500 ppm showed anthelmintic activities in the order ethylacetate > methanol > hexane from the alcoholic crude extract. The isolated betulinic acid from the ethylacetate fraction at 100 and 500 ppm showed strong anthelmintic activities comparable to piperazine. These results confirm the traditional use of Berlina grandiflora as an anthelmintic and indicate that betulinic acid is the active component.