Insecticidal activities and active ingredients of Stephania kwangsiensis Lo. were studied for the first time. The results showed that all parts of S. kwangsiensis Lo. had contact activity against brown planthoppers, N...Insecticidal activities and active ingredients of Stephania kwangsiensis Lo. were studied for the first time. The results showed that all parts of S. kwangsiensis Lo. had contact activity against brown planthoppers, Nilaparvata lugens Stal, and the contact activity of methanol extract from root tubers was the highest, with a LD50 value being 1.5794 μg/female. l-roemerine was isolated from root tubers of S. kwangsiensis Lo. and identified, and it was the main active ingredient. l-roemerine had high contact toxicity to brown planthoppers, with a LD50 value being 0.0443 μg/female. Contact toxicity of l-roemerine to brown planthoppers was 7.48 times that of malathion, the convientional chemical insecticide used for controlling brown planthoppers. l-roemerine also had stomach poison activity against brown planthoppers.展开更多
Active oxygen quantum yield,insecticidal activities and stability of diphenylthiophene were studied for the first time.The results showed that maximum diphenylthiophene absorbency variety was 0.438 after irradiation f...Active oxygen quantum yield,insecticidal activities and stability of diphenylthiophene were studied for the first time.The results showed that maximum diphenylthiophene absorbency variety was 0.438 after irradiation for 280 min and that ofα- terthienyl(α-T)was 0.480 after irradiation for 200 min with UV.LC 50 values of diphenylthiophene andα-T against 3rd instar larvae of Aedes albopictus were 9.18×10-3 and 9.69×10-4μg mL-1 when treated for 24 h,respectively.LC 50 values of the two chemicals against the 3rd instar larvae of Plutella xylostella were 267.87 and 222.22μg mL-1 when treated for 24 h, respectively.The half lives of diphenylthiophene andα-T in methanol were 113.62 and 10.65 h.Difference between quantum yield of diphenylthiophene andα-T was not significant and they all possessed high toxicity to Aedes albopictus and Plutella xylostella,but diphenylthiophene was more stable thanα-T.It could be concluded that diphenylthiophene has overcome the deficiency of photoactivated insecticides which degraded quickly in the environment and could not be applied on the field.Diphenylthiophene could kill the insects and accelerate the degradation rate of triazophos.The benefits of diphenylthiophene can be further exploited and applied on the field.展开更多
During our continuous efforts towards the search for environmental benign insect antifeedant, we established a concise method for the synthesis of Tonghaosu, a naturally occurring antifeedant.[1] Herein, we report... During our continuous efforts towards the search for environmental benign insect antifeedant, we established a concise method for the synthesis of Tonghaosu, a naturally occurring antifeedant.[1] Herein, we report the synthesis and antifeeding activity of 22 new tonghaosu analogs, which contain varied B ring as well as one or two acetylene functionalities. Preliminary bioassay indicates that two acetylene groups containing tonghaosu analogs have better antifeedant activity against large white butterfly (Pieris brassicae L.) than those with one acetylene group. More interestingly,Z-isomers are much more active than their corresponding E-isomers.……展开更多
A new series of phenoxy-phenyl moieties containing tonghaosu analogs with varied B-ring 9 were synthesized and characterized by spectral studies. Their insect antifeedant activity against Pieris brassicae and insectic...A new series of phenoxy-phenyl moieties containing tonghaosu analogs with varied B-ring 9 were synthesized and characterized by spectral studies. Their insect antifeedant activity against Pieris brassicae and insecticidal ac-tivity against Culex quinquefasciatus were investigated. Compound 9e exhibited excellent antifeeding activity.展开更多
The methanolic extract from a Chinese endemic Chrysanthemum plant, Dendranthema indicum var. aromaticum, was found to show high antifeeding activity against Pieris brassicae L., and by bioassay-guided separation, the ...The methanolic extract from a Chinese endemic Chrysanthemum plant, Dendranthema indicum var. aromaticum, was found to show high antifeeding activity against Pieris brassicae L., and by bioassay-guided separation, the ac-tive component, B-ring-homo-tonghaosu, 2-(2’,4’-hexadiynylidene)-1,6-dioxaspiro-[4,5]-dec-3-ene (2) was isolated. Its structure was elucidated by comparing its spectroscopic data with those of 2 reported in the literatures. Further-more new convenient total synthesis methods of B-ring-homo-tonghaosu were also developed to confirm its struc-ture and make its further application in crop protection available. In addition, extensive comparison of spectroscopic data showed that the structure of compound 21 reported in literature should be revised to 2.展开更多
基金the Natural Science Foundation of Guangdong Province(03683).
文摘Insecticidal activities and active ingredients of Stephania kwangsiensis Lo. were studied for the first time. The results showed that all parts of S. kwangsiensis Lo. had contact activity against brown planthoppers, Nilaparvata lugens Stal, and the contact activity of methanol extract from root tubers was the highest, with a LD50 value being 1.5794 μg/female. l-roemerine was isolated from root tubers of S. kwangsiensis Lo. and identified, and it was the main active ingredient. l-roemerine had high contact toxicity to brown planthoppers, with a LD50 value being 0.0443 μg/female. Contact toxicity of l-roemerine to brown planthoppers was 7.48 times that of malathion, the convientional chemical insecticide used for controlling brown planthoppers. l-roemerine also had stomach poison activity against brown planthoppers.
基金National Science and Technology Achievements 0utreach Program,Ministry of Science and Technology,China(2003440051163)Natural Science Foundation of Guangdong Provincial Department of Science and Technology,China(04300516)Key Laboratory of Pesticide and Chemical Biology,Ministry of Education,South China Agricultural University(04-08)for providing financial support.
文摘Active oxygen quantum yield,insecticidal activities and stability of diphenylthiophene were studied for the first time.The results showed that maximum diphenylthiophene absorbency variety was 0.438 after irradiation for 280 min and that ofα- terthienyl(α-T)was 0.480 after irradiation for 200 min with UV.LC 50 values of diphenylthiophene andα-T against 3rd instar larvae of Aedes albopictus were 9.18×10-3 and 9.69×10-4μg mL-1 when treated for 24 h,respectively.LC 50 values of the two chemicals against the 3rd instar larvae of Plutella xylostella were 267.87 and 222.22μg mL-1 when treated for 24 h, respectively.The half lives of diphenylthiophene andα-T in methanol were 113.62 and 10.65 h.Difference between quantum yield of diphenylthiophene andα-T was not significant and they all possessed high toxicity to Aedes albopictus and Plutella xylostella,but diphenylthiophene was more stable thanα-T.It could be concluded that diphenylthiophene has overcome the deficiency of photoactivated insecticides which degraded quickly in the environment and could not be applied on the field.Diphenylthiophene could kill the insects and accelerate the degradation rate of triazophos.The benefits of diphenylthiophene can be further exploited and applied on the field.
文摘 During our continuous efforts towards the search for environmental benign insect antifeedant, we established a concise method for the synthesis of Tonghaosu, a naturally occurring antifeedant.[1] Herein, we report the synthesis and antifeeding activity of 22 new tonghaosu analogs, which contain varied B ring as well as one or two acetylene functionalities. Preliminary bioassay indicates that two acetylene groups containing tonghaosu analogs have better antifeedant activity against large white butterfly (Pieris brassicae L.) than those with one acetylene group. More interestingly,Z-isomers are much more active than their corresponding E-isomers.……
基金Project supported by the National Natural Science Foundation of China （Nos. 29672083, 20072043）, the Chinese Academy of Sciences, the Ministry of Science and Technology of China （No. G2000077502）, and the Shanghai Commission of Science and Technology.
基金the National Natural Science Foundation of China (Nos. 29672083, 20072043), the Chinese Academy of Sciences, the State Ministry of Science and Technology (No. 2000077502), the Shanghai Committee of Science and Technology.
文摘A new series of phenoxy-phenyl moieties containing tonghaosu analogs with varied B-ring 9 were synthesized and characterized by spectral studies. Their insect antifeedant activity against Pieris brassicae and insecticidal ac-tivity against Culex quinquefasciatus were investigated. Compound 9e exhibited excellent antifeeding activity.
基金the National Natural Science Foundation of China (Grant Nos. 29672083, 20072043), Chinese Academy of Sciences, the State Ministry of Science and Technology (No. G2000077502), Shanghai Committee of Science and Technology and the
文摘The methanolic extract from a Chinese endemic Chrysanthemum plant, Dendranthema indicum var. aromaticum, was found to show high antifeeding activity against Pieris brassicae L., and by bioassay-guided separation, the ac-tive component, B-ring-homo-tonghaosu, 2-(2’,4’-hexadiynylidene)-1,6-dioxaspiro-[4,5]-dec-3-ene (2) was isolated. Its structure was elucidated by comparing its spectroscopic data with those of 2 reported in the literatures. Further-more new convenient total synthesis methods of B-ring-homo-tonghaosu were also developed to confirm its struc-ture and make its further application in crop protection available. In addition, extensive comparison of spectroscopic data showed that the structure of compound 21 reported in literature should be revised to 2.
