• Journal of the Korean Wood Science and Technology
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• 제43권2호
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• pp.274-285
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• 2015

In view of the environmental and health hazards posed by synthetic insecticides, the use of plant products as botanical insecticides has gained increasing in recent years. In this study, we reported the insecticidal activity of extracts isolated from Coptis chinensis. On crude extraction, among the various solvent types tested (water, 1% (w/v) of sodium hydroxide, 70% ethanol), the 70% ethanol extract showed the best insecticidal activity (36.5%). Three different fractions (n-hexane, chloroform and ethyl acetate) were obtained from crude extract (70% ethanol) of the chloroform fraction and found to have noteworthy insecticidal activity (62.9%) by filter paper contact bioassay. Their chemical structures were identified as 2-methoxy-4-vinylphenol and aniline by head space-GC-MS analysis. Both compounds displayed a dose-dependent insecticidal activity of Myzus persicae (Sulzer). Insecticidal activity at the lowest concentration tested (500 ppm) approached 85.4% in the aniline compared with 79.9% in the 2-methoxy-4-vinylphenol. The insecticidal activity was greater for the aniline than 2-methoxy-4-vinylphenol. It is believed that the insecticidal activity is due mainly to the presence of aniline.

• Journal of the Korean Wood Science and Technology
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• 제42권5호
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• pp.624-633
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• 2014

This study separated the crude extract (70% ethanol) of and its three fractions (hexane, chloroform and ethyl acetate extracts) on the basis of polarity indexes, and examined for their insecticidal activities against aphid (Uroleucon lactucicola). For crude extraction, the 70% ethanol extract showed the best extract yield (58.0%) and insecticidal activity (69.0%) among the various concentrations tested (water, 30% ethanol, 50% ethanol, 70% ethanol and 95% ethanol). The major chemical compounds of different fractions (hexane, chloroform and ethyl acetate extracts) were identified as eugenol by head space-GC-MS analysis. The hexane extract showed the highest eugenol content (43.7%) and insecticidal activity (80.0%). The insecticidal activity is accordingly believed to be attributable to the eugenol component. This may provide a useful starting point for the development of bio-pesticides.

• 한국환경보건학회지
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• 제21권1호
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• pp.74-77
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• 1995

The insecticidal and antibacterial activity of new synthesized carbamate derivatives(8-Hydroxy-5-chloroquinolyl-N-methylcarbamate(I), 8-Hydroxy-5-chloroquinolyl-N-ethylcarbamate(II)) was examined using 0.2 w/v% acetone solutiolas and 50 r/ml~1000 r/m N,N'-dimethylformamide-$H_2O$(2:3) solutions of each compounds, respectively. 1) Two carbamates exerted insecticidal effects on Sogata furcifera HORVATH, Delphacodes Striatella FAUEN, Whereas no significant effects were observed on the Nilaparvate lugens STAL, Inazuma dorasails MOISCHIULSKY and Nephateffix apicalis Cincticeps UHLER. 2) These compounds exhibited growth-inhibitory activity against Staphylococcus aureus, Salmonella paratyphi A, Shigella dysenteriae 1a, Escherichia coli NL 1401,at the concentration range of 100~500 r/ml in general.

• 한국유기농업학회지
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• 제19권spc호
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• pp.275-278
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• 2011

To find an alternative for synthetic pesticides, methanol extracts from 69 plant samples were tested for their insecticidal activity against two spotted mite (Tetranchus urticae Koch). Seven plant extracts including Angelica japonica showed over 80% insecticidal activity at 5000 mg/L. Extract of Prunus armeniaca seed showed high insecticidal activity at 3000 mg/L. As a naturally occurring pesticide, P. armeniaca could be useful as a new botanic insecticide.

• 농약과학회지
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• 제5권1호
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• pp.24-29
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• 2001

은행잎함유 살충성분인 bilobalide의 활성부위를 조사하기 위해 bilobalide를 가수분해 및 산화를 시킨 후 구조를 확인하고 살충활성을 검정하였다. 분해물의 분석 결과, 염기에 의한 가수분해물은 cyclopentenone 계열의 화합물로 밝혀졌고, 산화물은 trilactone 형태를 유지한 sesquiterpene 구조로써 dehydration된 형태로 추정되었다. 분해물의 살충활성을 검정한 결과, 살충력의 크기는 bilobalide, monoacetyl 유도체, ginkgolide C, 산화분해물, diacetyl 유도체, 가수분해물의 순으로 감소하여 bilobalide의 살충력을 나타내는데에는 trilactone의 구조를 유지하는 것이 중요한 것으로 나타났다.

• 한국미생물·생명공학회지
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• 제38권2호
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• pp.117-123
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• 2010

BT toxin is produced by a soil bacterium Bacillus thuringiensis and has long been used as a biological insecticide without any competition. Recently, Photorhabdus, a symbiotic bacterium from entomopathogenic nematodes, family Heterorhabditae, has been researched and discussed as alternatives to B. thuringiensis. Photorhabdus, which lives in the gut of entomopathogenic nematodes, is a highly virulent pathogen of a wide range of insect larvae. When an insect is infected by the nematodes, the bacteria are released into the cadaver, and produce a number of insecticidal toxins. The biological role of the different Photorhabdus toxins in the infection process is still unclear. Photorhabdus toxin complex (Tc) is highly secreted gut-active toxin and has been characterized as a potent three-component (A, B and C) insecticidal protein complex. These components are necessary for full oral activity against insect larvae. The Photorhabdus PirAB binary toxins exhibit a potent injectable activity for Galleria mellonella larvae, and have oral toxicity against mosquitoes and caterpillar pest Plutella xylostella. Other toxin, 'makes caterpillars floppy' (Mcf) showed injectable activity on caterpillars. Recombinant Mcf triggers apoptosis in both insect hemocytes and the midgut epithelium and carries a BH3 domain. In this review, the relationship between the Photorhabdus and the nematode is discussed and recent important insecticidal toxins from Photorhabdus are described.

• 한국환경농학회지
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• 제37권2호
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• pp.125-134
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• 2018

BACKGROUND: Green peach aphid (Myzus persicae) is an insect pest that significantly affects crop production. A number of pesticides have been used for aphid control, but their concerns on insect resistance and food safety have required alternative methods for pest management. In an effort to find for an alternative approach to aphid control, we screened plants extracts and examined their potentiality as insecticidal bio-resources. METHODS AND RESULTS: Two hundred and ninety eight plant extracts were examined for insecticidal activity against the aphid, and the best candidate among them was chosen for further study. The extracts from Cinnamomum camphora was determined to be the best candidate exhibiting insecticidal activity more than 60% at a level of $1,000{\mu}g/mL$. GC/MS analyses detected camphor, borneol, 4-terpineol, ${\alpha}$-terpineol and caryophyllene oxide as major compositions from the extracts obtained by hydrodistillation. Caryophyllene oxide exhibited the highest insecticidal activity with a $LC_{50}$ value of $237{\mu}g/mL$. Camphor lowered significantly the $LC_{50}$ value of caryophyllene oxide and increased largely its concentration in aphid, suggesting that camphor played a role in enhancing the insecticidal activity of caryophyllene oxide. CONCLUSION: This study suggested that camphor and caryophyllene oxide may be used as an insecticidal bio-resource for insect control against green peach aphid.

• 농업과학연구
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• 제41권3호
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• pp.177-185
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• 2014

Aspiring to the new raw materials of insecticides is one of the plant extracts. The material structure of a variety of plant extracts have because the material to the defense of the plant itself, the case of insecticides, using plant extracts, safe, has low toxicity and has the advantage of highly distinctive and fall. Coltsfoot (Tussilago farfara L.) is belonging to the family Compositae, and distributed in all parts of China as medicinal plants and indigenous plants used. Coltsfoot is known that it is effect to respiratory disease and has an antiviral effect. However, the reported insecticidal activity of coltsfoot could be not found. Fortunately, I found insecticidal activities when I was screening the bioassay against several insects with a lot of plant extracts. Using the ethanol extract of the Tussilago farfara, there were insecticidal activities against Culex pipiens pallens and Tetranychus urticae. There were several fractions in ethanol extract of coltsfoot by using various organic solvents. Hexane fraction showed a higher insecticidal activity than any other fraction. It is confirmed that hexane fraction contained pyrethrin by using HPLC analysis. So, it might be suggested that extract of coltsfoot has an insecticidal activity and its effect due to a ingredient of pyrethrin.

• 한국자원식물학회지
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• 제26권1호
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• pp.19-25
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• 2013

본 연구는 살충효과가 알려진 식물체들 중 8종을 공시하여 배추좀나방에 대하여 살충효과의 여부를 검정하고 친환경 유기농산물 재배에 활용할 수 있는지 검토하였다. 식물 추출물 $1500mg{\cdot}L^{-1}$에서 48시간 후의 배추좀나방 살충율은 고추씨 추출물이 83.3%로 가장 높았다. 생물검정을 해서 배추좀나방 방제효과가 있는 고추씨, 애기똥풀, 익모초, 박하, 황련 식물추출물 5종을 선발하였다. 선발한 식물체 5종의 약해 검정 결과 열무와 엇갈이배추의 발아, 유아, 유엽의 생장에 해로운 영향을 미치지 않았다. 온실 안에서 pot에 식물추출물을 처리하여 조사하였는데 열무는 황련추출물을 처리할 때 73.3%의 방제가를 보였고, 고추씨 추출물도 70%의 방제가를 나타냈다. 엇갈이배추는 황련추출물을 처리할 때 70%, 고추씨 추출물을 처리할 때 방제가가 66.7%이었다. 포장에서 선발한 식물추출물의 효과를 피해 엽률로 조사한 결과, 열무는 고추씨 추출물을 처리했을 때 방제가가 62.4%로 나타났다. 엇갈이배추는 황련추출물을 처리할 때 64.6% 방제가를 보였다. 식물추출물을 12회를 처리 한 후 수확 전에 조사한 결과 열무는 황련추출물 및 고추씨추출물은 방제가가 87.4%, 83.7%였고, 엇갈이배추는 방제가가 황련추출물이 74.3%, 애기똥풀 추출물이 69.3%를 나타냈다.

• 농업과학연구
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• 제45권2호
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• pp.185-196
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• 2018

The fungus gnat, Bradysia difformis, damages various crops in greenhouses and is recognized as an important pest around the world. Additionally, in the future, many other greenhouse crops will be added to the list of crops damaged by the fungus gnat. In this study, to find effective control methods for the fungus gnat, the insecticidal effect of 20 chemical synthetic insecticides was tested with the potato disc and pot treatment methods; additionally, the control effect of 16 strains of B. thuringiensis was examined with the potato disk method. The fungus gnat larvae were treated for 2 days with each of the synthetic insecticides to determine insecticidal effect using the potato disc method. The results were as follows. Among the highly insecticidal active pesticides, chlorfenapyr exhibited a 100% insecticidal activity, and fenazaquin, acetamiprid, dinotefuran, fenthion and thiamethoxam exhibited more than a 90% insecticidal activity. For the pot treatment method, chlorfenapyr exhibited a 3.3% insecticidal effect, and thiamethoxam, acetamiprid, dinotefuran, fenthion, etc. exhibited an insecticidal effect of less than 10% of the emergence rate to adult fungus gnat after 14 days of treatment. To select the B. thuringiensis strains that have an insecticidal effect on the fungus gnat, 16 strains were biologically assayed using the potato disc method. Among the 16 strains, Bt-3, Bt-8 and Bt-13 had more than a 70% insecticidal effect. The $LC_{50}$ and $LC_{95}$ values of Bt-3, Bt-8 and Bt-13 were $3.7{\times}10^5$ and $4.7{\times}10^8cfu/ml$, $1.4{\times}10^5$ and $1.1{\times}10^7cfu/ml$, and $1.4{\times}10^5$ and $1.3{\times}10^7cfu/ml$, respectively.