The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
R N C Guedes - One of the best experts on this subject based on the ideXlab platform.
-
survival and developmental impairment induced by the trypsin inhibitor bis Benzamidine in the velvetbean caterpillar anticarsia gemmatalis
Crop Protection, 2011Co-Authors: L F Moreira, Wellington G Campos, Fabricio Rainha Ribeiro, R N C Guedes, Maria Goreti De Almeida OliveiraAbstract:Proteinase inhibitors are potential insect control agents, but insect adaptation to these compounds is one of the main limitations for their potential use as such. The velvetbean caterpillar (Anticarsia gemmatalis Hubner) (Lepidoptera: Noctuidae) is a key soybean pest species well-adapted to its prevailing (serine-) proteinase inhibitors, particularly trypsin-like inhibitors. The recognition of proteinase inhibitors with insecticidal activity towards such pest species is therefore challenging and important as a basis for the development of mimetic peptides with potential use as biorational insecticides. Thus, bis-Benzamidine was tested against the velvetbean caterpillar with the expectation of greater insecticidal activity of this more potent trypsin inhibitor than the negligible effects observed with other natural and synthetic trypsin inhibitors. Bis-Benzamidine ingestion by the caterpillars led to higher survival time with increased doses up to 76 ppm, but drastically reduced survival time at higher doses (over 150 ppm). Insects exposed to bis-Benzamidine doses of up to 76 ppm exhibited extended larval development and decreased pupa weight. Increased doses of this trypsin inhibitor led to increased diet consumption and protein digestibility during the larval phase, but drastically compromised the proteolytic activity in the caterpillar gut. These results indicate that, unlike Benzamidine, another related synthetic trypsin inhibitor, bis-Benzamidine exhibits insecticidal activity towards the velvetbean caterpillars at doses as low as 9.5 ppm in the insect diet due to suppression of gut proteinase activity despite the compensatory feeding. Such compensatory feeding may however increase insect damage in the field by more tolerant individuals and should be the object of further study.
-
Adaptation of the velvetbean caterpillar Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) to the protease inhibitor Benzamidine.
2009Co-Authors: Anderson Martins Pilon, R N C Guedes, M. G. A. Oliveira, Franciny Martins Pilon, Joel Antônio De Oliveira, A. FazolloAbstract:Adaptation of the velvetbean caterpillar Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae) to the protease inhibitor Benzamidine The serine protease inhibitor Benzamidine inhibits hydrolyses of trypsin-like digestive proteases in the midgut of velvetbean caterpillar, Anticarsia gemmatalis. In this study, newly-emerged A. gemmatalis caterpillars were fed on artificial diet containing increasing concentrations of Benzamidine (0, 0.25, 0.50 e 0.75% w/w). This inhibitor caused negative effects in the insect development, by increasing the larval cycle and higher mortality. Nonetheless even at the highest Benzamidine concentration, the insect mortality was low, suggesting that the insect is able to adapt to this inhibitor. Such adaptation may take place by increasing the amount of protease produced for digestion or changing the prevailing type of protease.
-
protein digestibility protease activity and post embryonic development of the velvetbean caterpillar anticarsia gemmatalis exposed to the trypsin inhibitor Benzamidine
Pesticide Biochemistry and Physiology, 2006Co-Authors: Anderson Martins Pilon, Maria Goreti De Almeida Oliveira, R N C GuedesAbstract:Protein digestibility, proteolytic activity, and post-embryonic development of Anticarsia gemmatalis (Hubner) (Lepidoptera: Noctuidae) were assessed in larvae reared on artificial diet containing 0.00, 0.25, 0.50, and 0.75% (w/w) of the synthetic trypsin inhibitor Benzamidine. Diet consumption was affected by the inhibitor when the insects were exposed to 0.50% Benzamidine showing a 4-day delay and a 70%-higher peak of consumption. Larva weight gain was also affected by Benzamidine and again the results of 0.50% Benzamidine were unexpected due to the worst performance of the insects at this inhibitor concentration and not at 0.75% Benzamidine. These patterns of consumption and weight gain were however consistent with the results of protein digestibility, which affects larvae mortality and adult emergence. The insect proteolytic activity was also affected by Benzamidine, particularly at 0.50%. These results indicate that the insects are able to circumvent the potentially harmful effects of the inhibitor since at the highest concentration the negative impact is mitigated.
Fu Shi - One of the best experts on this subject based on the ideXlab platform.
-
Palladium(II)‐Catalyzed C—H Activation and C—C Coupling/Cyclization of Benzamidine and Terminal Alkynes Using an Internal Oxidant.
ChemInform, 2016Co-Authors: Xu Zhang, Zhiqiang Wang, Zhao Qiang, Fu ShiAbstract:Herein, an efficient palladium(II)-catalyzed C–C coupling/cyclization reaction by directed C–H activation of Benzamidine and terminal alkynes has been developed. In this practical and high-yielding process, the C–N bond acts as an internal oxidant. It was found that molecules with both electron-donating and electron-withdrawing substituents were suitable substrates for this transformation, and the expected products were obtained in moderate to excellent yields, but when the Benzamidine with ortho-methyl substituent is employed, the Benzamidine compound may undergo the [1,5]-hydrogen migration, and then Diels–Alder reaction with terminal alkynes to produce the quinoline compound. The use of a single catalytic system to mediate chemical transformations in a synthetic operation is efficient in building complex structures from simple starting materials in an environmentally benign fashion.
-
palladium ii catalyzed c h activation and c c coupling cyclization of Benzamidine and terminal alkynes using an internal oxidant
Synlett, 2015Co-Authors: Xu Zhang, Zhiqiang Wang, Qiang Zhao, Fu ShiAbstract:Herein, an efficient palladium(II)-catalyzed C–C coupling/cyclization reaction by directed C–H activation of Benzamidine and terminal alkynes has been developed. In this practical and high-yielding process, the C–N bond acts as an internal oxidant. It was found that molecules with both electron-donating and electron-withdrawing substituents were suitable substrates for this transformation, and the expected products were obtained in moderate to excellent yields, but when the Benzamidine with ortho-methyl substituent is employed, the Benzamidine compound may undergo the [1,5]-hydrogen migration, and then Diels–Alder reaction with terminal alkynes to produce the quinoline compound. The use of a single catalytic system to mediate chemical transformations in a synthetic operation is efficient in building complex structures from simple starting materials in an environmentally benign fashion.
Anderson Martins Pilon - One of the best experts on this subject based on the ideXlab platform.
-
Protease inhibitory, insecticidal and deterrent effects of the trypsin-inhibitor Benzamidine on the velvetbean caterpillar in soybean
Anais da Academia Brasileira de Ciencias, 2018Co-Authors: Anderson Martins Pilon, Wellington G Campos, Carolina Rodrigues De Jesus Silva, Gláucia Cordeiro, Camila Rocha Silva, Maria Goreti De Almeida OliveiraAbstract:The recognition of protease inhibitors with insecticidal activity is important as a basis for the development of mimetic peptides with potential use as biorational insecticides. We sprayed Benzamidine on soybean plants and assessed whether this potent synthetic trypsin-inhibitor has protease inhibitory, insecticidal and deterrent effects on the velvetbean caterpillar Anticarsia gemmatalis Hubner (Lepidoptera: Erebidae). Activity of trypsin inhibition in soybean leaves was increased and total proteolytic activity in the midgut extract from larvae fed on these leaves was reduced by Benzamidine. Different concentrations of Benzamidine sprayed on the plant caused approximately 50 % of larval mortality, and larval choice and moth preference and oviposition were all negatively affected. Low concentrations of Benzamidine increased mortality and hindered insect choice and oviposition as well as higher doses. Since many synthetic protease inhibitors are usually expensive, small doses of Benzamidine may be effective to protect soybean against A. gemmatalis attack. Our results highlight the potential of synthetic protease inhibitors for insecticidal and deterrent purposes in insect pest management.
-
Adaptation of the velvetbean caterpillar Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) to the protease inhibitor Benzamidine.
2009Co-Authors: Anderson Martins Pilon, R N C Guedes, M. G. A. Oliveira, Franciny Martins Pilon, Joel Antônio De Oliveira, A. FazolloAbstract:Adaptation of the velvetbean caterpillar Anticarsia gemmatalis Hubner (Lepidoptera: Noctuidae) to the protease inhibitor Benzamidine The serine protease inhibitor Benzamidine inhibits hydrolyses of trypsin-like digestive proteases in the midgut of velvetbean caterpillar, Anticarsia gemmatalis. In this study, newly-emerged A. gemmatalis caterpillars were fed on artificial diet containing increasing concentrations of Benzamidine (0, 0.25, 0.50 e 0.75% w/w). This inhibitor caused negative effects in the insect development, by increasing the larval cycle and higher mortality. Nonetheless even at the highest Benzamidine concentration, the insect mortality was low, suggesting that the insect is able to adapt to this inhibitor. Such adaptation may take place by increasing the amount of protease produced for digestion or changing the prevailing type of protease.
-
protein digestibility protease activity and post embryonic development of the velvetbean caterpillar anticarsia gemmatalis exposed to the trypsin inhibitor Benzamidine
Pesticide Biochemistry and Physiology, 2006Co-Authors: Anderson Martins Pilon, Maria Goreti De Almeida Oliveira, R N C GuedesAbstract:Protein digestibility, proteolytic activity, and post-embryonic development of Anticarsia gemmatalis (Hubner) (Lepidoptera: Noctuidae) were assessed in larvae reared on artificial diet containing 0.00, 0.25, 0.50, and 0.75% (w/w) of the synthetic trypsin inhibitor Benzamidine. Diet consumption was affected by the inhibitor when the insects were exposed to 0.50% Benzamidine showing a 4-day delay and a 70%-higher peak of consumption. Larva weight gain was also affected by Benzamidine and again the results of 0.50% Benzamidine were unexpected due to the worst performance of the insects at this inhibitor concentration and not at 0.75% Benzamidine. These patterns of consumption and weight gain were however consistent with the results of protein digestibility, which affects larvae mortality and adult emergence. The insect proteolytic activity was also affected by Benzamidine, particularly at 0.50%. These results indicate that the insects are able to circumvent the potentially harmful effects of the inhibitor since at the highest concentration the negative impact is mitigated.
Maria Goreti De Almeida Oliveira - One of the best experts on this subject based on the ideXlab platform.
-
Protease inhibitory, insecticidal and deterrent effects of the trypsin-inhibitor Benzamidine on the velvetbean caterpillar in soybean
Anais da Academia Brasileira de Ciencias, 2018Co-Authors: Anderson Martins Pilon, Wellington G Campos, Carolina Rodrigues De Jesus Silva, Gláucia Cordeiro, Camila Rocha Silva, Maria Goreti De Almeida OliveiraAbstract:The recognition of protease inhibitors with insecticidal activity is important as a basis for the development of mimetic peptides with potential use as biorational insecticides. We sprayed Benzamidine on soybean plants and assessed whether this potent synthetic trypsin-inhibitor has protease inhibitory, insecticidal and deterrent effects on the velvetbean caterpillar Anticarsia gemmatalis Hubner (Lepidoptera: Erebidae). Activity of trypsin inhibition in soybean leaves was increased and total proteolytic activity in the midgut extract from larvae fed on these leaves was reduced by Benzamidine. Different concentrations of Benzamidine sprayed on the plant caused approximately 50 % of larval mortality, and larval choice and moth preference and oviposition were all negatively affected. Low concentrations of Benzamidine increased mortality and hindered insect choice and oviposition as well as higher doses. Since many synthetic protease inhibitors are usually expensive, small doses of Benzamidine may be effective to protect soybean against A. gemmatalis attack. Our results highlight the potential of synthetic protease inhibitors for insecticidal and deterrent purposes in insect pest management.
-
survival and developmental impairment induced by the trypsin inhibitor bis Benzamidine in the velvetbean caterpillar anticarsia gemmatalis
Crop Protection, 2011Co-Authors: L F Moreira, Wellington G Campos, Fabricio Rainha Ribeiro, R N C Guedes, Maria Goreti De Almeida OliveiraAbstract:Proteinase inhibitors are potential insect control agents, but insect adaptation to these compounds is one of the main limitations for their potential use as such. The velvetbean caterpillar (Anticarsia gemmatalis Hubner) (Lepidoptera: Noctuidae) is a key soybean pest species well-adapted to its prevailing (serine-) proteinase inhibitors, particularly trypsin-like inhibitors. The recognition of proteinase inhibitors with insecticidal activity towards such pest species is therefore challenging and important as a basis for the development of mimetic peptides with potential use as biorational insecticides. Thus, bis-Benzamidine was tested against the velvetbean caterpillar with the expectation of greater insecticidal activity of this more potent trypsin inhibitor than the negligible effects observed with other natural and synthetic trypsin inhibitors. Bis-Benzamidine ingestion by the caterpillars led to higher survival time with increased doses up to 76 ppm, but drastically reduced survival time at higher doses (over 150 ppm). Insects exposed to bis-Benzamidine doses of up to 76 ppm exhibited extended larval development and decreased pupa weight. Increased doses of this trypsin inhibitor led to increased diet consumption and protein digestibility during the larval phase, but drastically compromised the proteolytic activity in the caterpillar gut. These results indicate that, unlike Benzamidine, another related synthetic trypsin inhibitor, bis-Benzamidine exhibits insecticidal activity towards the velvetbean caterpillars at doses as low as 9.5 ppm in the insect diet due to suppression of gut proteinase activity despite the compensatory feeding. Such compensatory feeding may however increase insect damage in the field by more tolerant individuals and should be the object of further study.
-
protein digestibility protease activity and post embryonic development of the velvetbean caterpillar anticarsia gemmatalis exposed to the trypsin inhibitor Benzamidine
Pesticide Biochemistry and Physiology, 2006Co-Authors: Anderson Martins Pilon, Maria Goreti De Almeida Oliveira, R N C GuedesAbstract:Protein digestibility, proteolytic activity, and post-embryonic development of Anticarsia gemmatalis (Hubner) (Lepidoptera: Noctuidae) were assessed in larvae reared on artificial diet containing 0.00, 0.25, 0.50, and 0.75% (w/w) of the synthetic trypsin inhibitor Benzamidine. Diet consumption was affected by the inhibitor when the insects were exposed to 0.50% Benzamidine showing a 4-day delay and a 70%-higher peak of consumption. Larva weight gain was also affected by Benzamidine and again the results of 0.50% Benzamidine were unexpected due to the worst performance of the insects at this inhibitor concentration and not at 0.75% Benzamidine. These patterns of consumption and weight gain were however consistent with the results of protein digestibility, which affects larvae mortality and adult emergence. The insect proteolytic activity was also affected by Benzamidine, particularly at 0.50%. These results indicate that the insects are able to circumvent the potentially harmful effects of the inhibitor since at the highest concentration the negative impact is mitigated.
Xu Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Palladium(II)‐Catalyzed C—H Activation and C—C Coupling/Cyclization of Benzamidine and Terminal Alkynes Using an Internal Oxidant.
ChemInform, 2016Co-Authors: Xu Zhang, Zhiqiang Wang, Zhao Qiang, Fu ShiAbstract:Herein, an efficient palladium(II)-catalyzed C–C coupling/cyclization reaction by directed C–H activation of Benzamidine and terminal alkynes has been developed. In this practical and high-yielding process, the C–N bond acts as an internal oxidant. It was found that molecules with both electron-donating and electron-withdrawing substituents were suitable substrates for this transformation, and the expected products were obtained in moderate to excellent yields, but when the Benzamidine with ortho-methyl substituent is employed, the Benzamidine compound may undergo the [1,5]-hydrogen migration, and then Diels–Alder reaction with terminal alkynes to produce the quinoline compound. The use of a single catalytic system to mediate chemical transformations in a synthetic operation is efficient in building complex structures from simple starting materials in an environmentally benign fashion.
-
palladium ii catalyzed c h activation and c c coupling cyclization of Benzamidine and terminal alkynes using an internal oxidant
Synlett, 2015Co-Authors: Xu Zhang, Zhiqiang Wang, Qiang Zhao, Fu ShiAbstract:Herein, an efficient palladium(II)-catalyzed C–C coupling/cyclization reaction by directed C–H activation of Benzamidine and terminal alkynes has been developed. In this practical and high-yielding process, the C–N bond acts as an internal oxidant. It was found that molecules with both electron-donating and electron-withdrawing substituents were suitable substrates for this transformation, and the expected products were obtained in moderate to excellent yields, but when the Benzamidine with ortho-methyl substituent is employed, the Benzamidine compound may undergo the [1,5]-hydrogen migration, and then Diels–Alder reaction with terminal alkynes to produce the quinoline compound. The use of a single catalytic system to mediate chemical transformations in a synthetic operation is efficient in building complex structures from simple starting materials in an environmentally benign fashion.