In present investigation, various bioassays were conducted to evaluate the alteration in levels of certain biomolecules, such as glycogen, protein, amino acid, DNA, RNA and lipids. For this purpose, worker termites we...In present investigation, various bioassays were conducted to evaluate the alteration in levels of certain biomolecules, such as glycogen, protein, amino acid, DNA, RNA and lipids. For this purpose, worker termites were treated with sub-lethal dose 40% and 80% of 24 hrs LD<sub>50</sub> values and observations were taken at 4 hrs interval up to 24 hrs. Crude latex and its combinatorial mixtures, like S-MLT-A, B-MLT-A, C-MLT-A, CU-MLT-A, AQ-MLT significantly altered level of bio-molecules in Odontotermes obesus. This effect was found time and dose dependent. Reduction or increase in biomolecules was calculated by using corresponding control. Maximum decrease in glycogen level was observed at 16 h when termites were treated with 80% of LD<sub>50</sub> of Ficus benghalensis aqueous extract i.e. 56.88% at 16 h of treatment. A similar dose caused very slight decrease in lipid contents at 4 h of treatment but it was found further significantly (p > 0.05) decreased in other successive treatments. 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture caused significant (p > 0.05) decrease in DNA and RNA level at 16 h treatment. The level of DNA and RNA level was recorded 83.90%, 90.18% and 85.42% and 74.05% respectively. Similarly, total proteins were also found to be decreased with 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture i.e. 71.47% and 66.45% respectively. All these alterations found in levels of various bio-molecules confirm the action of latex ingredients on worker termites that was antifeedant or deterrent types. These ingredients can be used to control not only termites but also other phytophagous insects in a sustainable and eco-friendly way.展开更多
Seven compounds were isolated from the EtOH extraction of the twig of Carapa guianensis Aubl. (Meliaceae). On the basis of spectroscopic methods, their structures were elucidated as (-)-epicatechin-3-O-(3' , 5'...Seven compounds were isolated from the EtOH extraction of the twig of Carapa guianensis Aubl. (Meliaceae). On the basis of spectroscopic methods, their structures were elucidated as (-)-epicatechin-3-O-(3' , 5'-di-O-methyl) gallate (1), (-)-catechin (2), sciadopitysin (3), cleomiscosin B (4), photogedunin (5), chisocheton compound F (6) and odoratone (7), respectively. Among them compound 1 was a new flavane, compounds 2-7 were firstly obtained from this plant, and compound 5 was assigned the C-13-NMR data for the first time. Compound 7 exhibited strong antifeedant activity against Pieris brassicae, and compound 2 exhibited moderate activity, while the n-BuOH portion showed weak activity.展开更多
[ Objective] The paper was to study the contact toxicity and antifeedant activity of Aconitum flavum against cabbage worm. [ Method ] In- sect dipping method was adopted to determine the contact toxicity of the extrac...[ Objective] The paper was to study the contact toxicity and antifeedant activity of Aconitum flavum against cabbage worm. [ Method ] In- sect dipping method was adopted to determine the contact toxicity of the extracts of A. fiavum extracted from five polar solvents including ethanol, petroleum ether, ether, ethyl acetate, n-butanol and water; leaf dish method was adopted to determine the antifeedant activities of five solvent ex- tracts including ethanol, petroleum ether, ether, ethyl acetate, n-butanol and water against cabbage worm, [ Result] Extracts of A. flavum had high contact toxicity against cabbage worm. When the concentration was 100.00 mg/ml, the corrected mortality at 48 h roached 97.24%, and the insec- ticidal activities of five solvent extracts against cabbage worm in sequence were water 〉 n-butanol 〉 ethyl acetate 〉 ether 〉 petroleum ether, the cor- rected mortality of water extract at 48 h was 95.87% ; the antifeedant activities of five solvent extracts in sequence were water 〉 n-butanol 〉 ethyl ac- etate 〉 ether 〉 petroleum ether. [ Conclusion] Extracts of A. flavum had strong contact toxicity and antifeedant activity against cabbage worm, and the active ingredients with contact toxicity and antifeedant activity might be a kind of polar compound.展开更多
[Objective] Insecticidal activities of alkaloids extracted from 12 poisonous plants in Changbai Mountain were studied in the paper,to provide the basis for development and utilization of poisonous plants in Changbai M...[Objective] Insecticidal activities of alkaloids extracted from 12 poisonous plants in Changbai Mountain were studied in the paper,to provide the basis for development and utilization of poisonous plants in Changbai Mountain.[Method] Leaf disc method was used to study the effects of alkaloids extracted from 12 poisonous plants on the growth and development of 3-5 instars of cabbage worm (Pieris rapae) and their antifeedant activities.[Result] The effects of alkaloids extracted from different poisonous plants on the growth and development of cabbage worm were also different.Five treatments of alkaloids extracted from Sophora flavescens,Datura stramonium L.,Arisaema amurense Maxim.,Veratum dahuricum Loes.and Tripterygium regelii Spragne et Takeda made the weight of test insects gradually decrease and finally die;the alkaloid treatments of Pueraria lobata (Willd.) Ohwi,Aconitum kusnezoffii Reichb.,Cimicifuga dahurica (Turcz.) Maxim.and Corydalis ambigua Schleeht.could make cabbage worm pupate ahead of time,but the pupa state was deformed;the antifeedant rates of cabbage worm after the treatments of P.lobata,A.kusnezoffii,C.dahurica,A.amurense,V.dahuricum and C.ambigua for 48 h were all over 90%,and the antifeedant rates of C.dahurica and C.ambigua were the highest as 100%.[Conclusion]The reports on the insecticidal activities of five poisonous plants including P.lobata,A.kusnezoffii,C.dahurica,C.ambigua and A.amurense are rare,and they have important values on the development of botanical pesticides.展开更多
[Objective] The aim was to study the biological activity of insecticidal components of Seleng Wormwood on cabbage butterfly (Pieris rapae).[Method] With the assisted condition of microwave heating,ethanol,ethyl ethe...[Objective] The aim was to study the biological activity of insecticidal components of Seleng Wormwood on cabbage butterfly (Pieris rapae).[Method] With the assisted condition of microwave heating,ethanol,ethyl ether,water and methylbenzene were selected as solvents to extract Seleng Wormwood,and the antifeedant,stomach toxicity,contact toxicity and fumigation activities of various solvent extracts against cabbage butterfly were determined.[Result] Various solvent extracts all showed certain antifeedant,stomach toxicity,contact toxicity and fumigation activity against the larvae of cabbage butterfly,and the biological activity of ethanol extract was the strongest.[Conclusion]The results could provide reference for development and utilization of botanical pesticides of Seleng Wormwood.展开更多
Objective:To evaluate the antifeedant,insecticidal and growth inhibition activities of Solanum pseudocapsicum(S.pseudocapsicum)seed extracts against Spodoptera litura(S.litura)and Helicotverpa armigera(H.armigera).Met...Objective:To evaluate the antifeedant,insecticidal and growth inhibition activities of Solanum pseudocapsicum(S.pseudocapsicum)seed extracts against Spodoptera litura(S.litura)and Helicotverpa armigera(H.armigera).Methods:Hcxane,diethyl cther,dichloromethanc and ethyl acetate seed extracts were prepared and tested for autifeedant,insecticidal and growth inhibitory activities against fourth instar larvae of&litura and H.armigera.Results:Ethyl acetate extract showed promising antifeedant and insecticidal activities against S.litura and H.armigera.Percentage of deformed larvae,pupae and adults were maximum in treatment of ethyl acetate extract.Percentage of successful adult emergence was deteriorated by seeds on extract treated larvae.Conclusions:Ethyl acetate extracts of S.pseudocapsicum,showed higher efficiency of antifeedant,insecticidal and growth inhibition activities.Hence,it can be used to controll agricultural insect pests,S.litura and H.armigera.展开更多
The perennial herbaceous plant Euphorbia jolkinii(Euphorbiaceae)is a noxious weed widely distributed in the grasslands of northwestern Yunnan and has greatly threatened the local biodiversity.Phytochemical investigati...The perennial herbaceous plant Euphorbia jolkinii(Euphorbiaceae)is a noxious weed widely distributed in the grasslands of northwestern Yunnan and has greatly threatened the local biodiversity.Phytochemical investigation on the fresh roots of E.jolkinii afforded six new diterpenoids 1,2,4–6,and 8,together with fifteen known diterpenoids.Their structures were elucidated on the basis of 1D and 2D NMR and other spectroscopic methods.Casbane,lathyrane,abietane,and ent-kaurane diterpenoids were reported from this plant for the first time.Selected compounds were evaluated for their antifeedant and anti-RSV(respiratory syncytial virus)activities.Compound 2 and ingenol(3)exhibited moderate antifeedant activity against a generalist insect herbivore,Spodoptera exigua,with EC50 values of 17.88 and 17.71 lg/cm2 respectively.Compound 19 showed significant anti-RSV activity,with 50%inhibition(IC50)value of 10.0 lM and selective index of 8.0.Compounds 1 and 2 were less active against RSV virus,both with IC50 value of 25 lM,and with selective indices of 1.0 and 3.2 respectively.These findings provided new evidence for the biological functions and utilization of the diversified diterpenoid metabolites in the roots of this rich but harmful plant.展开更多
With the bioguided fractionation of the ethanol extracts from the leaves of Momordica charantia, we obtained two most active compounds against the feeding of the diamondback moth, Plutella xylostella larvae. The antif...With the bioguided fractionation of the ethanol extracts from the leaves of Momordica charantia, we obtained two most active compounds against the feeding of the diamondback moth, Plutella xylostella larvae. The antifeedant activity of momordicine Ⅰ and momordicine Ⅱ against the second and the third instar larvae of Plutella xylostella were tested using leaf discs of cabbage in the laboratory. The results showed that momordicin Ⅰ and momordicin Ⅱ had significant antifeedant activity on the larvae of P. xylostella, and momordicin Ⅱ was more active than momordicin Ⅰ. The concentrations for 50% antifeedant effects (AFC50) of momordicin Ⅱ against the second and the third instar larvae of P. xylostella were 76.69 and 116.24μg mL^-1, whereas that of momordicin I was 144.08 and 168.42μg mL^-1, respectively. In addition, momordicin Ⅰ and momordicin Ⅱ had significant inhibitive effect on the rate of weight gain and survival of P. xylostella larvae.展开更多
Growth inhibitory activity has proven important in Qiufeng×Baiyu and Qingsong×Haoyue silkworm larvae. The consumption of mulberry leaves was reduced in both silkworm races while Qiufeng×Baiyu larvae s...Growth inhibitory activity has proven important in Qiufeng×Baiyu and Qingsong×Haoyue silkworm larvae. The consumption of mulberry leaves was reduced in both silkworm races while Qiufeng×Baiyu larvae showed the higher reduction in leaf consumption. From the results obtained, it was revealed that even at low concentrations of 400 mg/L of either Cr(Ⅲ) or Cr(Ⅵ) ions, growth of Qiufeng × Baiyu and Qingsong × Haoyue was significantly depressed. Depression in relative growth index(RGI) and high death rate in both silkworm races indicated that the different concentrations of the two ions used caused their growth inhibitions. Through linear regression analysis, the EC 50 (concentration of the compound that caused 50% reduction) was interpolated for both tested compounds. EC 50 (mg/L) of Cr (Ⅲ) ions in Qiufeng × Baiyu and Qingsong × Haoyue were 800 and 600 respectively. EC 50 (mg/L) of Cr(Ⅵ) ions in Qiufeng × Baiyu and Qingsong × Haoyue was 600 and 316 respectively. According to the analysis of relative growth index, and an analysis of linear regression technique for measuring the growth of the silkworm races, it was indicated that the form of Cr affected growth rates, growth inhibition responses of the larvae, and toxicological effects. Thus, form and quantity of Cr accumulating in silkworms reared with contaminated leaves are likely to influence their population dynamics.展开更多
Objetive: To explore the potential insecticidal, ovipositor deterrent and antifeedant effects of ethyl acetate extract of the seeds of Senna tora(Syn. Cassia tora) against cowpea weevil(Callosobruchus maculatus).Metho...Objetive: To explore the potential insecticidal, ovipositor deterrent and antifeedant effects of ethyl acetate extract of the seeds of Senna tora(Syn. Cassia tora) against cowpea weevil(Callosobruchus maculatus).Method: The activities were evaluated using standard protocols.In these bioassays, the cowpea seeds were used directly as an insect feed. The activity of the extract and isolated compounds were tested at concentrations of 100, 200 and 300 μg/mL and compared to neem oil and cinnamaldehyde(as standard positive controls). Phytochemical analysis of the ethyl acetate extract was done through a number of chromatographic techniques and the structures of the isolated compounds were established through comprehensive spectroscopic analysis including 2 D-NMR and ESI-MS studies.Results: Fractionation of the active ethyl acetate extract resulted in the isolation of one known anthraquinone,aurantio-obtusin(1) and a novel compound that was named as cassiatorin(2). Compounds1 and 2 showed comparable insect antifeedant properties with the positive controls while their insecticidal and ovipositor deterrent effects were far superior to the standard controls.Conclusions: It is thus concluded that Senna tora extracts and the isolated compounds(1 and2) may be employed in the postharvest management of stored cowpea seeds and as other crop protectants.展开更多
Two new highly oxygenated limonoids,flexuosoids A(1)and B(2),and three new arylnaphthalene lignan glycosides,phyllanthusmins D–F(3–5),were isolated from the roots of Phyllanthus flexuosus,in addition to three known ...Two new highly oxygenated limonoids,flexuosoids A(1)and B(2),and three new arylnaphthalene lignan glycosides,phyllanthusmins D–F(3–5),were isolated from the roots of Phyllanthus flexuosus,in addition to three known lignans,phyllanthusmin C,arabelline,and(?)-diasyringaresinol.Their structures were elucidated on the basis of detailed spectroscopic analysis and chemical methods.Compounds 1 and 2,two new decaoxygenated limonoids with a C-19/29 lactol bridge and heptaoxygenated substituents at C-1,C-2,C-3,C-7,C-11,C-17,and C-30,represent the second example of limonoids in the Euphorbiaceae family.Most of the isolates were tested for their antifeedant,anti-herpes simplex virus 1,and cytotoxic activities.The new limonoids 1 and 2 showed promising antifeedant activity against the beet army worm(Spodoptera exigua)with EC50 values of 25.1 and 17.3 lg/cm2,respectively.In addition,both of them displayed moderate cytotoxicity against the ECA109 human esophagus cancer cell line,along with the known lignan glycoside,phyllanthusmin C,with the IC50 values of 11.5(1),8.5(2),and 7.8(phyllanthusmin C)lM,respectively.展开更多
Due to the severity of the disease and yield losses of corn, this study had achieved a novel corn seed coating agent which was prepared with polysaccharide, fertilizer, microelement and other assistants as raw materia...Due to the severity of the disease and yield losses of corn, this study had achieved a novel corn seed coating agent which was prepared with polysaccharide, fertilizer, microelement and other assistants as raw materials. The dilution and the pH value of the corn seed coating agent, were studied. And the biological toxicity and potential hazards of the agent to environmental protection were assessed. Over the whole trial, the best formula and optimum conditions of a new corn seed coating agent were determined. Also results indicated that compared with the traditional one Jinong No. 4, yields of corn was increased over 9.5%, but cost was reduced over 18.75%. To sum up, this agent self-made had three primary characteristics of high yield, less cost and friendly environment. So it had an important value of application and promotion in main production zone of corn and can bring us obvious economic and environmental benefits.展开更多
This paper summarized of the chemistry characteristics of tannins and their various adverse effects onmammalian herbivore, including the chemical nature of hydrolyzable and condensed tannins, their analysis mathods, a...This paper summarized of the chemistry characteristics of tannins and their various adverse effects onmammalian herbivore, including the chemical nature of hydrolyzable and condensed tannins, their analysis mathods, and the tannins antifeedant mechanisms.展开更多
In vitro biological activities including anti-phytopathogenic fungi, antibacterial, antifeedant and herbicidal activities of the extracts from the heartwoods of Mansonia gagei Drumm. were evaluated. The dichlorometha...In vitro biological activities including anti-phytopathogenic fungi, antibacterial, antifeedant and herbicidal activities of the extracts from the heartwoods of Mansonia gagei Drumm. were evaluated. The dichloromethane (DCM) extract displayed antifungal activity against four plant pathogenic fungi (Altemaria porri, Colletotrichum gloeosporioides, Fusarium oxysporum and Phytophthora parasitica) higher than the methanolic (MeOH) extract. The separation of the DCM extract using bioassay guided antifungal activity against P. parasiUca led to the isolation of mansorins A, B, and C, mansonones C, E, G and H. Among isolated compounds, mansonone E displayed the highest antifungal activity against P. parasitica, followed by mansonone C, mansorin B and mansonone G. This potent compound revealed the same minimum inhibitory concentrations (MIC) of 31 μg mL-1 against C. gloeosporioides and P. parasitica, and minimum fungicidal concentration (MFC) of 31 and 125 μg mL-1, respectively. Moreover, mansonone E exhibited highly significant antibacterial activity against both Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc) with MIC and minimum bactericidal concentration (MBC) as 7.8 and 〉500μg mL-1, respectively. This compound furthermore could inhibit the feed of Spodoptera litura with 45.9% antifeedant and significantly herbicidal activity reduced the shoot and root growth of Brassica chinensis, Oryza sativa, Mimosa pigra and Echinochlooa crus-galli. Mansonone E has potential as a new natural pesticide for agricultural plant pathogen management.展开更多
Creating high-efifcient and environment-friendly pesticides is very important to produce the pollution free agriculture food and maintain the balance of the survival environmental of the human being. According to repo...Creating high-efifcient and environment-friendly pesticides is very important to produce the pollution free agriculture food and maintain the balance of the survival environmental of the human being. According to reports, camptothecin (CPT) and its derivatives are now being explored as a class of botanical insecticide in agriculture due to its novel mode of action. In order to improve the insecticidal activity of CPT, ten novel camptothecin (1) and 10-hydroxycamptothecin (2) derivatives (1a, 1b, 1c, 1d, 1e;2a, 2b, 2c, 2d, 2e) were designed and synthesized via esteriifcation with analogs of chrysanthemic acid, which have outstanding insecticidal activity. The results showed that compound 2a exhibited potent antifeeding effect and the best contact toxicity among the target compounds against the third-instar larvae of beet armyworm, Spodoptera exigua H&#252;bner. Compound 2a was also found to be the most effective cytotoxic compound to the tested insect cell lines, IOZCAS-Spex-II, which were established from the fat bodies of S. exigua. It was proposed that the 10-hydroxyl group in the camptothecin derivatives is a key factor for the antifeeding activity of a compound. The nature of the substituents was considered the major factor in determining the insecticidal activity of these compounds.展开更多
This study scrutinized the possibility of finding toxicant or deterrent plant metabolites against the dry wood termite Incisitermes marginipennis(Latreille).Plant deterrent agents act as repellents or antifeedants to ...This study scrutinized the possibility of finding toxicant or deterrent plant metabolites against the dry wood termite Incisitermes marginipennis(Latreille).Plant deterrent agents act as repellents or antifeedants to prevent wood decay and increase its useful life.The potential of the tree Caesalpinia coriaria(Fabaceae)as a biological source of molecules with deterrent effects against the dry wood termite was assessed by a phytochemical fractionation guided by repellence and antifeedant activities.The gas chromatography-mass spectrometry analysis of the leaf essential oil showed geraniol to be one of the major components and its repellent and antifeedant effects were determined.Geraniol had only an antifeedant effect without affecting the body weight or survival of the dry wood termite.Unlike the leaf essential oil,geraniol did not exhibit a repellency effect.An in-silico approach of the activity of acetylcholinesterase in interaction with geraniol resulted in an affinity energy of−7.5 Kcal/mol.Geraniol interacted with the amino acid tyrosine 324 located in the enzyme’s active site while citronellol(negative control)interacted with tryptophan 83 located adjacent to the active site.These deterring terpenes have not been implemented for the preservation and restoration of wood products exposed to the attack of the dry wood termite.However,they are an important natural control alternative.展开更多
We analyzed the composition and studied the bioactivity of secretion from the poplar sawfly, Stauronematus compressicornis (Fabricius). A leaf-sandwich method was applied to test the bioactivity of the secretion. Co...We analyzed the composition and studied the bioactivity of secretion from the poplar sawfly, Stauronematus compressicornis (Fabricius). A leaf-sandwich method was applied to test the bioactivity of the secretion. Coomassie brilliant blue, gas chromatography (GC) and other methods were used to analyze and carry out protein assays, amino acid analyses, fatty acid and cholesterol detection of the secretion. Results show that the secretion had a significant antifeeding effect on 4th instar larvae of the armyworm (Pseudaletia separata Walker). Dissolved in 0.27 mol.L^-1 HCl, 0.1 mol.L^-1 NaOH and 0.05 mol.L^-1 Na2HPO4 separately, the secretions had antifeeding rates ranging from 22.7% to 49.6%. Meanwhile, the weights of the secretion-treated insects were significantly lower than those of the control. Biochemical detection showed that the proteins contained in the secretion were composed of 16 amino acids. The secretion also contained small amounts of cholesterol and fatty acids, which included lauric acid, myristic acid, myristoleic acid, seventeen carbonic acids and oleic acid.展开更多
An efficient synthesis of functionalized 6-decalone 16, starting from a dienolate anion 3a via a tandem Michael reaction, is described. 16 could be used as a potential intermediate for synthesis of drimane related ses...An efficient synthesis of functionalized 6-decalone 16, starting from a dienolate anion 3a via a tandem Michael reaction, is described. 16 could be used as a potential intermediate for synthesis of drimane related sesquiterpenes.展开更多
[Objectives] This study was conducted to expand the insect resistance spectrum of tea saponin, and its control effect on Cylas formicarius and the potential as an insecticide for pest control were explored. [Methods] ...[Objectives] This study was conducted to expand the insect resistance spectrum of tea saponin, and its control effect on Cylas formicarius and the potential as an insecticide for pest control were explored. [Methods] The olfactory avoidance rate of C. formicarius to tea saponin aqueous solution was determined by Y-type olfactometer;the feeding avoidance rate of C. formicarius to tea saponin was determined by the selective method;the antifeedant rate of C. formicarius to tea saponin was determined by non-selective method;and the development duration and mortality of C. formicarius under the influence of tea saponin were determined by artificial feeding method. [Results] C. formicarius had no significant olfactory tendency to every concentration of tea saponin, and the olfactory avoidance rate of 20.0% tea saponin aqueous solution was only 9.14%. Tea saponin had a feeding avoidance effect on C. formicarius, and the avoidance rate increased with the increase of tea saponin concentration. At 6 h, the feeding avoidance rates of 0.5%, 1.0%, 5.0%, 10.0% and 20.0% tea saponin on C. formicarius were 58.14%, 77.77%, 88.23%, 95.00% and 97.65 %, respectively;and the feeding avoidance effect at 6 h was significant, and the feeding avoidance rate was higher than that of 1 h. Tea saponin had a significant antifeedant effect on C. formicarius, and the longer the feeding time, the higher the antifeedant rate. At 72 h, the antifeedant rates of 0.5%, 1.0%, 5.0%, 10.0 % and 20.0% tea saponin to C. formicarius were 63.01%, 67.54%, 97.14 %, 96.42% and 98.57%, respectively. The larval development duration of C. formicarius was shortened with the increase of tea saponin concentration, and the larval death occurred. The development duration of larvae under the influence of 1.0% tea saponin was the shortest, which was 4.01 d shorter than that of the control, and the mortality was the highest, which was 26.65%. [Conclusions] Tea saponin had neither olfactory avoidance effect nor olfactory attracting effect to C. formicarius, but had obvious feeding avoidance effect and strong antifeedant effect. Tea saponin can shorten the development duration of the larvae of C. formicarius and cause the death of the larvae.展开更多
Crude leaf extracts of Eucalyptus camaldulensis and Tylophora indica were evaluated for their antifeedancy against Helicoverpa armigera larvae in no-choice bioassays. Cabbage leaf-disc dipped in different concentratio...Crude leaf extracts of Eucalyptus camaldulensis and Tylophora indica were evaluated for their antifeedancy against Helicoverpa armigera larvae in no-choice bioassays. Cabbage leaf-disc dipped in different concentrations of leaf extracts was used for feeding fifth instars of H. armigera for 24 hours. Ethanol extracts from both the plant species exhibited significant feeding inhibition, activity. The effective concentrations of ethanol extracts that caused 50% reduction in larval feeding (EI50) were 6.9% for E. camaldulensis and 2.8% for T. indica, while these values of hexane extracts were 9.3% and 5.2%, respectively. Compared to the crude leaf extracts, crude alkaloids from T. indica and crude tannins from E. camaldulensis were more potent in reducing larval feedings.展开更多
文摘In present investigation, various bioassays were conducted to evaluate the alteration in levels of certain biomolecules, such as glycogen, protein, amino acid, DNA, RNA and lipids. For this purpose, worker termites were treated with sub-lethal dose 40% and 80% of 24 hrs LD<sub>50</sub> values and observations were taken at 4 hrs interval up to 24 hrs. Crude latex and its combinatorial mixtures, like S-MLT-A, B-MLT-A, C-MLT-A, CU-MLT-A, AQ-MLT significantly altered level of bio-molecules in Odontotermes obesus. This effect was found time and dose dependent. Reduction or increase in biomolecules was calculated by using corresponding control. Maximum decrease in glycogen level was observed at 16 h when termites were treated with 80% of LD<sub>50</sub> of Ficus benghalensis aqueous extract i.e. 56.88% at 16 h of treatment. A similar dose caused very slight decrease in lipid contents at 4 h of treatment but it was found further significantly (p > 0.05) decreased in other successive treatments. 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture caused significant (p > 0.05) decrease in DNA and RNA level at 16 h treatment. The level of DNA and RNA level was recorded 83.90%, 90.18% and 85.42% and 74.05% respectively. Similarly, total proteins were also found to be decreased with 40% and 80% of LD<sub>50</sub> of C-MLT-B mixture i.e. 71.47% and 66.45% respectively. All these alterations found in levels of various bio-molecules confirm the action of latex ingredients on worker termites that was antifeedant or deterrent types. These ingredients can be used to control not only termites but also other phytophagous insects in a sustainable and eco-friendly way.
文摘Seven compounds were isolated from the EtOH extraction of the twig of Carapa guianensis Aubl. (Meliaceae). On the basis of spectroscopic methods, their structures were elucidated as (-)-epicatechin-3-O-(3' , 5'-di-O-methyl) gallate (1), (-)-catechin (2), sciadopitysin (3), cleomiscosin B (4), photogedunin (5), chisocheton compound F (6) and odoratone (7), respectively. Among them compound 1 was a new flavane, compounds 2-7 were firstly obtained from this plant, and compound 5 was assigned the C-13-NMR data for the first time. Compound 7 exhibited strong antifeedant activity against Pieris brassicae, and compound 2 exhibited moderate activity, while the n-BuOH portion showed weak activity.
基金Supported by Scientific and Technological Projects of Ningxia Hui Autonomous Region(2008220)~~
文摘[ Objective] The paper was to study the contact toxicity and antifeedant activity of Aconitum flavum against cabbage worm. [ Method ] In- sect dipping method was adopted to determine the contact toxicity of the extracts of A. fiavum extracted from five polar solvents including ethanol, petroleum ether, ether, ethyl acetate, n-butanol and water; leaf dish method was adopted to determine the antifeedant activities of five solvent ex- tracts including ethanol, petroleum ether, ether, ethyl acetate, n-butanol and water against cabbage worm, [ Result] Extracts of A. flavum had high contact toxicity against cabbage worm. When the concentration was 100.00 mg/ml, the corrected mortality at 48 h roached 97.24%, and the insec- ticidal activities of five solvent extracts against cabbage worm in sequence were water 〉 n-butanol 〉 ethyl acetate 〉 ether 〉 petroleum ether, the cor- rected mortality of water extract at 48 h was 95.87% ; the antifeedant activities of five solvent extracts in sequence were water 〉 n-butanol 〉 ethyl ac- etate 〉 ether 〉 petroleum ether. [ Conclusion] Extracts of A. flavum had strong contact toxicity and antifeedant activity against cabbage worm, and the active ingredients with contact toxicity and antifeedant activity might be a kind of polar compound.
基金Supported by School Fund in Yanbian University (201015)~~
文摘[Objective] Insecticidal activities of alkaloids extracted from 12 poisonous plants in Changbai Mountain were studied in the paper,to provide the basis for development and utilization of poisonous plants in Changbai Mountain.[Method] Leaf disc method was used to study the effects of alkaloids extracted from 12 poisonous plants on the growth and development of 3-5 instars of cabbage worm (Pieris rapae) and their antifeedant activities.[Result] The effects of alkaloids extracted from different poisonous plants on the growth and development of cabbage worm were also different.Five treatments of alkaloids extracted from Sophora flavescens,Datura stramonium L.,Arisaema amurense Maxim.,Veratum dahuricum Loes.and Tripterygium regelii Spragne et Takeda made the weight of test insects gradually decrease and finally die;the alkaloid treatments of Pueraria lobata (Willd.) Ohwi,Aconitum kusnezoffii Reichb.,Cimicifuga dahurica (Turcz.) Maxim.and Corydalis ambigua Schleeht.could make cabbage worm pupate ahead of time,but the pupa state was deformed;the antifeedant rates of cabbage worm after the treatments of P.lobata,A.kusnezoffii,C.dahurica,A.amurense,V.dahuricum and C.ambigua for 48 h were all over 90%,and the antifeedant rates of C.dahurica and C.ambigua were the highest as 100%.[Conclusion]The reports on the insecticidal activities of five poisonous plants including P.lobata,A.kusnezoffii,C.dahurica,C.ambigua and A.amurense are rare,and they have important values on the development of botanical pesticides.
基金Supported by Doctoral Research Fund of Yangtze UniversityEducational Commission of Hubei Province of China(Q200712003)~~
文摘[Objective] The aim was to study the biological activity of insecticidal components of Seleng Wormwood on cabbage butterfly (Pieris rapae).[Method] With the assisted condition of microwave heating,ethanol,ethyl ether,water and methylbenzene were selected as solvents to extract Seleng Wormwood,and the antifeedant,stomach toxicity,contact toxicity and fumigation activities of various solvent extracts against cabbage butterfly were determined.[Result] Various solvent extracts all showed certain antifeedant,stomach toxicity,contact toxicity and fumigation activity against the larvae of cabbage butterfly,and the biological activity of ethanol extract was the strongest.[Conclusion]The results could provide reference for development and utilization of botanical pesticides of Seleng Wormwood.
基金Supported by University Grant Commission(UGC)X plan(Grant No.UGC/TN/GAC-2008)
文摘Objective:To evaluate the antifeedant,insecticidal and growth inhibition activities of Solanum pseudocapsicum(S.pseudocapsicum)seed extracts against Spodoptera litura(S.litura)and Helicotverpa armigera(H.armigera).Methods:Hcxane,diethyl cther,dichloromethanc and ethyl acetate seed extracts were prepared and tested for autifeedant,insecticidal and growth inhibitory activities against fourth instar larvae of&litura and H.armigera.Results:Ethyl acetate extract showed promising antifeedant and insecticidal activities against S.litura and H.armigera.Percentage of deformed larvae,pupae and adults were maximum in treatment of ethyl acetate extract.Percentage of successful adult emergence was deteriorated by seeds on extract treated larvae.Conclusions:Ethyl acetate extracts of S.pseudocapsicum,showed higher efficiency of antifeedant,insecticidal and growth inhibition activities.Hence,it can be used to controll agricultural insect pests,S.litura and H.armigera.
基金the National Natural Science Foundation of China(31200263)the Youth Innovation Promotion association of Chinese Academy of Sciences(awarded to Shi-Hong Luo)+1 种基金the“Western Light”Program of Chinese Academy of Sciences(awarded to Shi-Hong Luo)the“Hundred Talents Program”of Chinese Academy of Sciences(awarded to Sheng-Hong Li).
文摘The perennial herbaceous plant Euphorbia jolkinii(Euphorbiaceae)is a noxious weed widely distributed in the grasslands of northwestern Yunnan and has greatly threatened the local biodiversity.Phytochemical investigation on the fresh roots of E.jolkinii afforded six new diterpenoids 1,2,4–6,and 8,together with fifteen known diterpenoids.Their structures were elucidated on the basis of 1D and 2D NMR and other spectroscopic methods.Casbane,lathyrane,abietane,and ent-kaurane diterpenoids were reported from this plant for the first time.Selected compounds were evaluated for their antifeedant and anti-RSV(respiratory syncytial virus)activities.Compound 2 and ingenol(3)exhibited moderate antifeedant activity against a generalist insect herbivore,Spodoptera exigua,with EC50 values of 17.88 and 17.71 lg/cm2 respectively.Compound 19 showed significant anti-RSV activity,with 50%inhibition(IC50)value of 10.0 lM and selective index of 8.0.Compounds 1 and 2 were less active against RSV virus,both with IC50 value of 25 lM,and with selective indices of 1.0 and 3.2 respectively.These findings provided new evidence for the biological functions and utilization of the diversified diterpenoid metabolites in the roots of this rich but harmful plant.
基金the grants from the National Natural Science Foundation of China (39930120)
文摘With the bioguided fractionation of the ethanol extracts from the leaves of Momordica charantia, we obtained two most active compounds against the feeding of the diamondback moth, Plutella xylostella larvae. The antifeedant activity of momordicine Ⅰ and momordicine Ⅱ against the second and the third instar larvae of Plutella xylostella were tested using leaf discs of cabbage in the laboratory. The results showed that momordicin Ⅰ and momordicin Ⅱ had significant antifeedant activity on the larvae of P. xylostella, and momordicin Ⅱ was more active than momordicin Ⅰ. The concentrations for 50% antifeedant effects (AFC50) of momordicin Ⅱ against the second and the third instar larvae of P. xylostella were 76.69 and 116.24μg mL^-1, whereas that of momordicin I was 144.08 and 168.42μg mL^-1, respectively. In addition, momordicin Ⅰ and momordicin Ⅱ had significant inhibitive effect on the rate of weight gain and survival of P. xylostella larvae.
文摘Growth inhibitory activity has proven important in Qiufeng×Baiyu and Qingsong×Haoyue silkworm larvae. The consumption of mulberry leaves was reduced in both silkworm races while Qiufeng×Baiyu larvae showed the higher reduction in leaf consumption. From the results obtained, it was revealed that even at low concentrations of 400 mg/L of either Cr(Ⅲ) or Cr(Ⅵ) ions, growth of Qiufeng × Baiyu and Qingsong × Haoyue was significantly depressed. Depression in relative growth index(RGI) and high death rate in both silkworm races indicated that the different concentrations of the two ions used caused their growth inhibitions. Through linear regression analysis, the EC 50 (concentration of the compound that caused 50% reduction) was interpolated for both tested compounds. EC 50 (mg/L) of Cr (Ⅲ) ions in Qiufeng × Baiyu and Qingsong × Haoyue were 800 and 600 respectively. EC 50 (mg/L) of Cr(Ⅵ) ions in Qiufeng × Baiyu and Qingsong × Haoyue was 600 and 316 respectively. According to the analysis of relative growth index, and an analysis of linear regression technique for measuring the growth of the silkworm races, it was indicated that the form of Cr affected growth rates, growth inhibition responses of the larvae, and toxicological effects. Thus, form and quantity of Cr accumulating in silkworms reared with contaminated leaves are likely to influence their population dynamics.
基金The financial assistance from the Swedish International Development Agency for some of the study (travel grant for Valantine Mbatchou)
文摘Objetive: To explore the potential insecticidal, ovipositor deterrent and antifeedant effects of ethyl acetate extract of the seeds of Senna tora(Syn. Cassia tora) against cowpea weevil(Callosobruchus maculatus).Method: The activities were evaluated using standard protocols.In these bioassays, the cowpea seeds were used directly as an insect feed. The activity of the extract and isolated compounds were tested at concentrations of 100, 200 and 300 μg/mL and compared to neem oil and cinnamaldehyde(as standard positive controls). Phytochemical analysis of the ethyl acetate extract was done through a number of chromatographic techniques and the structures of the isolated compounds were established through comprehensive spectroscopic analysis including 2 D-NMR and ESI-MS studies.Results: Fractionation of the active ethyl acetate extract resulted in the isolation of one known anthraquinone,aurantio-obtusin(1) and a novel compound that was named as cassiatorin(2). Compounds1 and 2 showed comparable insect antifeedant properties with the positive controls while their insecticidal and ovipositor deterrent effects were far superior to the standard controls.Conclusions: It is thus concluded that Senna tora extracts and the isolated compounds(1 and2) may be employed in the postharvest management of stored cowpea seeds and as other crop protectants.
基金the NSFC 21002105,the 973 Program of Science and Technology of P.R.China(2011CB915503)the Fourteenth Batch Candidates of the Young Academic Leaders of Yunnan Province(Min XU,2011CI044)。
文摘Two new highly oxygenated limonoids,flexuosoids A(1)and B(2),and three new arylnaphthalene lignan glycosides,phyllanthusmins D–F(3–5),were isolated from the roots of Phyllanthus flexuosus,in addition to three known lignans,phyllanthusmin C,arabelline,and(?)-diasyringaresinol.Their structures were elucidated on the basis of detailed spectroscopic analysis and chemical methods.Compounds 1 and 2,two new decaoxygenated limonoids with a C-19/29 lactol bridge and heptaoxygenated substituents at C-1,C-2,C-3,C-7,C-11,C-17,and C-30,represent the second example of limonoids in the Euphorbiaceae family.Most of the isolates were tested for their antifeedant,anti-herpes simplex virus 1,and cytotoxic activities.The new limonoids 1 and 2 showed promising antifeedant activity against the beet army worm(Spodoptera exigua)with EC50 values of 25.1 and 17.3 lg/cm2,respectively.In addition,both of them displayed moderate cytotoxicity against the ECA109 human esophagus cancer cell line,along with the known lignan glycoside,phyllanthusmin C,with the IC50 values of 11.5(1),8.5(2),and 7.8(phyllanthusmin C)lM,respectively.
文摘Due to the severity of the disease and yield losses of corn, this study had achieved a novel corn seed coating agent which was prepared with polysaccharide, fertilizer, microelement and other assistants as raw materials. The dilution and the pH value of the corn seed coating agent, were studied. And the biological toxicity and potential hazards of the agent to environmental protection were assessed. Over the whole trial, the best formula and optimum conditions of a new corn seed coating agent were determined. Also results indicated that compared with the traditional one Jinong No. 4, yields of corn was increased over 9.5%, but cost was reduced over 18.75%. To sum up, this agent self-made had three primary characteristics of high yield, less cost and friendly environment. So it had an important value of application and promotion in main production zone of corn and can bring us obvious economic and environmental benefits.
文摘This paper summarized of the chemistry characteristics of tannins and their various adverse effects onmammalian herbivore, including the chemical nature of hydrolyzable and condensed tannins, their analysis mathods, and the tannins antifeedant mechanisms.
基金the office of the Higher Education Commission,Thailand for supporting grant fund under the program Strategic Scholarships for Frontier Research Network for the Ph D Program Thai Doctoral degree for this research (77/2551)the 90th Anniversary of Chulalongkorn University Fund (Ratchadaphiseksomphot Endowment Fund,GCUGR11244525026D24)
文摘In vitro biological activities including anti-phytopathogenic fungi, antibacterial, antifeedant and herbicidal activities of the extracts from the heartwoods of Mansonia gagei Drumm. were evaluated. The dichloromethane (DCM) extract displayed antifungal activity against four plant pathogenic fungi (Altemaria porri, Colletotrichum gloeosporioides, Fusarium oxysporum and Phytophthora parasitica) higher than the methanolic (MeOH) extract. The separation of the DCM extract using bioassay guided antifungal activity against P. parasiUca led to the isolation of mansorins A, B, and C, mansonones C, E, G and H. Among isolated compounds, mansonone E displayed the highest antifungal activity against P. parasitica, followed by mansonone C, mansorin B and mansonone G. This potent compound revealed the same minimum inhibitory concentrations (MIC) of 31 μg mL-1 against C. gloeosporioides and P. parasitica, and minimum fungicidal concentration (MFC) of 31 and 125 μg mL-1, respectively. Moreover, mansonone E exhibited highly significant antibacterial activity against both Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc) with MIC and minimum bactericidal concentration (MBC) as 7.8 and 〉500μg mL-1, respectively. This compound furthermore could inhibit the feed of Spodoptera litura with 45.9% antifeedant and significantly herbicidal activity reduced the shoot and root growth of Brassica chinensis, Oryza sativa, Mimosa pigra and Echinochlooa crus-galli. Mansonone E has potential as a new natural pesticide for agricultural plant pathogen management.
基金supported by the National Natural Science Foundation of China (31171878,31071707 and 31000851)
文摘Creating high-efifcient and environment-friendly pesticides is very important to produce the pollution free agriculture food and maintain the balance of the survival environmental of the human being. According to reports, camptothecin (CPT) and its derivatives are now being explored as a class of botanical insecticide in agriculture due to its novel mode of action. In order to improve the insecticidal activity of CPT, ten novel camptothecin (1) and 10-hydroxycamptothecin (2) derivatives (1a, 1b, 1c, 1d, 1e;2a, 2b, 2c, 2d, 2e) were designed and synthesized via esteriifcation with analogs of chrysanthemic acid, which have outstanding insecticidal activity. The results showed that compound 2a exhibited potent antifeeding effect and the best contact toxicity among the target compounds against the third-instar larvae of beet armyworm, Spodoptera exigua H&#252;bner. Compound 2a was also found to be the most effective cytotoxic compound to the tested insect cell lines, IOZCAS-Spex-II, which were established from the fat bodies of S. exigua. It was proposed that the 10-hydroxyl group in the camptothecin derivatives is a key factor for the antifeeding activity of a compound. The nature of the substituents was considered the major factor in determining the insecticidal activity of these compounds.
文摘This study scrutinized the possibility of finding toxicant or deterrent plant metabolites against the dry wood termite Incisitermes marginipennis(Latreille).Plant deterrent agents act as repellents or antifeedants to prevent wood decay and increase its useful life.The potential of the tree Caesalpinia coriaria(Fabaceae)as a biological source of molecules with deterrent effects against the dry wood termite was assessed by a phytochemical fractionation guided by repellence and antifeedant activities.The gas chromatography-mass spectrometry analysis of the leaf essential oil showed geraniol to be one of the major components and its repellent and antifeedant effects were determined.Geraniol had only an antifeedant effect without affecting the body weight or survival of the dry wood termite.Unlike the leaf essential oil,geraniol did not exhibit a repellency effect.An in-silico approach of the activity of acetylcholinesterase in interaction with geraniol resulted in an affinity energy of−7.5 Kcal/mol.Geraniol interacted with the amino acid tyrosine 324 located in the enzyme’s active site while citronellol(negative control)interacted with tryptophan 83 located adjacent to the active site.These deterring terpenes have not been implemented for the preservation and restoration of wood products exposed to the attack of the dry wood termite.However,they are an important natural control alternative.
基金supported by the National Natural Science Foundation of China (Grant No. 30872032).
文摘We analyzed the composition and studied the bioactivity of secretion from the poplar sawfly, Stauronematus compressicornis (Fabricius). A leaf-sandwich method was applied to test the bioactivity of the secretion. Coomassie brilliant blue, gas chromatography (GC) and other methods were used to analyze and carry out protein assays, amino acid analyses, fatty acid and cholesterol detection of the secretion. Results show that the secretion had a significant antifeeding effect on 4th instar larvae of the armyworm (Pseudaletia separata Walker). Dissolved in 0.27 mol.L^-1 HCl, 0.1 mol.L^-1 NaOH and 0.05 mol.L^-1 Na2HPO4 separately, the secretions had antifeeding rates ranging from 22.7% to 49.6%. Meanwhile, the weights of the secretion-treated insects were significantly lower than those of the control. Biochemical detection showed that the proteins contained in the secretion were composed of 16 amino acids. The secretion also contained small amounts of cholesterol and fatty acids, which included lauric acid, myristic acid, myristoleic acid, seventeen carbonic acids and oleic acid.
文摘An efficient synthesis of functionalized 6-decalone 16, starting from a dienolate anion 3a via a tandem Michael reaction, is described. 16 could be used as a potential intermediate for synthesis of drimane related sesquiterpenes.
基金Supported by National Modern Agricultural Industry Technology System Guangxi Industry Potato Innovation Team(nycytxgxcxtd-11-01)Guangxi Science and Technology Planning Project(GK AB16380046,GK AB18221101)
文摘[Objectives] This study was conducted to expand the insect resistance spectrum of tea saponin, and its control effect on Cylas formicarius and the potential as an insecticide for pest control were explored. [Methods] The olfactory avoidance rate of C. formicarius to tea saponin aqueous solution was determined by Y-type olfactometer;the feeding avoidance rate of C. formicarius to tea saponin was determined by the selective method;the antifeedant rate of C. formicarius to tea saponin was determined by non-selective method;and the development duration and mortality of C. formicarius under the influence of tea saponin were determined by artificial feeding method. [Results] C. formicarius had no significant olfactory tendency to every concentration of tea saponin, and the olfactory avoidance rate of 20.0% tea saponin aqueous solution was only 9.14%. Tea saponin had a feeding avoidance effect on C. formicarius, and the avoidance rate increased with the increase of tea saponin concentration. At 6 h, the feeding avoidance rates of 0.5%, 1.0%, 5.0%, 10.0% and 20.0% tea saponin on C. formicarius were 58.14%, 77.77%, 88.23%, 95.00% and 97.65 %, respectively;and the feeding avoidance effect at 6 h was significant, and the feeding avoidance rate was higher than that of 1 h. Tea saponin had a significant antifeedant effect on C. formicarius, and the longer the feeding time, the higher the antifeedant rate. At 72 h, the antifeedant rates of 0.5%, 1.0%, 5.0%, 10.0 % and 20.0% tea saponin to C. formicarius were 63.01%, 67.54%, 97.14 %, 96.42% and 98.57%, respectively. The larval development duration of C. formicarius was shortened with the increase of tea saponin concentration, and the larval death occurred. The development duration of larvae under the influence of 1.0% tea saponin was the shortest, which was 4.01 d shorter than that of the control, and the mortality was the highest, which was 26.65%. [Conclusions] Tea saponin had neither olfactory avoidance effect nor olfactory attracting effect to C. formicarius, but had obvious feeding avoidance effect and strong antifeedant effect. Tea saponin can shorten the development duration of the larvae of C. formicarius and cause the death of the larvae.
文摘Crude leaf extracts of Eucalyptus camaldulensis and Tylophora indica were evaluated for their antifeedancy against Helicoverpa armigera larvae in no-choice bioassays. Cabbage leaf-disc dipped in different concentrations of leaf extracts was used for feeding fifth instars of H. armigera for 24 hours. Ethanol extracts from both the plant species exhibited significant feeding inhibition, activity. The effective concentrations of ethanol extracts that caused 50% reduction in larval feeding (EI50) were 6.9% for E. camaldulensis and 2.8% for T. indica, while these values of hexane extracts were 9.3% and 5.2%, respectively. Compared to the crude leaf extracts, crude alkaloids from T. indica and crude tannins from E. camaldulensis were more potent in reducing larval feedings.