TCC - Bacharelado em Ciências Biológicas (Sede)
URI permanente para esta coleçãohttps://arandu.ufrpe.br/handle/123456789/412
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Item Avaliação da toxicidade do extrato de folhas de Annona squamosa para Aedes aegypti, Nasutitermes corniger e Sitophilus zeamais(2019-12-20) Santos, Lucas Gabriel Pita dos; Pontual, Emmanuel Viana; Almeida, Welton Aaron de; http://lattes.cnpq.br/6880632191779221; http://lattes.cnpq.br/1777060469196142; http://lattes.cnpq.br/5858954656778360The high environmental toxicity of the compounds currently used for control of insect pests, as well as the emergence of resistant populations have stimulated the search for new agents with insecticidal activity. In this work, an extract of Annona squamosa (Annonaceae) leaves was evaluated for the presence of proteins and secondary metabolites. The effect of the extract on larvae of Aedes aegypti (vector of dengue, yellow fever, zika and chikungunya) and adults of Nasutitermes corniger (urban pest) and Sitophilus zeamais (agricultural pest) was also investigated. The chemical characterization of the extract revealed the presence of proteins, lectin (HAE = 21,3) and trypsin inhibitor (15,6 U/mg) activities, as well as secondary metabolites the classes of flavonoids (rutin), cinnamic derivatives (chlorogenic acid), saponins, anthraquinones, terpenes and steroids. The extract was in toxic to A. aegypti larvae and the concentration required to kill 50% of larvae (CL50) was 1.9% (m/v). On the other hand, the extract did not affect the survival of N. corniger soldiers and workers. S. zeamais adults showed mortality ranging from 51.2 to 63.8% regarding the control when fed with the diet containing the extract (15 to 75 mg/g), but a strong deterrent feeding effect was detected. This data revealed that the insects die from starvation and not from intoxication due to the extract intake. The treatment with the extract resulted in high mortality of Hyalella sp. at the concentration corresponding to the LC50 for A. aegypti. However, the presence of the extract interferes with the pH and the amount of dissolved O2 in the culture solution, suggesting that Hyalella sp mortality cannot be a result of a direct toxicity of the extract. In conclusion, the A. squamosa leaf extract is an interesting candidate for use in the control of A. aegypti populations and as a protection agent for stored grains against the S. zeamais attack. Additionally, the use of the extract in the environment needs caution due to the high mortality detected for Hyalella sp.Item Folhas de Syzygium malaccense Linnaeus (Myrtaceae): caracterização química e efeitos sobre Plutella xylostella Linnaeus (Lepidoptera: Plutellidae)(2019-06-28) Santos Neto, Erasmo Guilherme dos; Pontual, Emmanuel Viana; Vila Nova, Isabella Coimbra; http://lattes.cnpq.br/8445185379848462; http://lattes.cnpq.br/1777060469196142; http://lattes.cnpq.br/6695192736858780Plutella xylostella (Plutellidae) is an important pest that attacks Brassicas cultures worldwide. Syzygium malaccense (Myrtaceae), or jambeiro, is used in popular medicine and its fruits are consumed as foodstuff. Lectins (carbohydrate-binding proteins) and trypsin inhibitors can be insecticidal agents. This work characterized the aqueous extract of S. malaccense for the presence of secondary metabolites, lectins and trypsin inhibitors, as well as for insidicidal activity against P. xylostella. Analysis by thin layer chromatography revealed the presence of polyphenols (hydrolyzed tannins), flavonoids, steroids, saponins and reducing sugars in the leaf extract, which also contained lectins (hemagglutinating activity of 64) and trypsin inhibitor. was inhibited by monosaccharides glucose and Nacetylglucosamine and neutralized by the glycoproteins fetuin and ovalbumin. The leaf extract exerted a detergent feed effect and induced mortality of P. xylostella caterpillars. The mortality rate of 80 ± 15% for the 1% leaf extract was recorded. The oviposition detergent effect was also determined for the leaf extract, since the presence of about 37 eggs was detected in the treated discs against 80 eggs recorded in the control. Exhaustive heating of the leaf extract altered the hemagglutinating and detergent food activities in a similar manner, suggesting that these can be attributed to the same protein. Exposure of leaf extract to environmental conditions for 192 h neutralized its food-producing effect. In conclusion, leaf extract of S. malaccense is a source of secondary metabolites, lectin and trypsin inhibitor, and constitutes an insecticidal agent against P. xylostella for causing mortality of caterpillars and altering their feeding and oviposition behaviors.Item Investigação do efeito do extrato de flores de Moringa oleifera Lamarck (Moringaceae) na sobrevivência e atividade de enzimas digestivas de larvas de Plutella xylostella Linnaeus (Lepidoptera: Plutellidae)(2019-02-01) Ferreira, Camila Azevedo; Pontual, Emmanuel Viana; Almeida, Welton Aaron de; http://lattes.cnpq.br/6880632191779221; http://lattes.cnpq.br/1777060469196142; http://lattes.cnpq.br/1108068314774367Plutella xylostella is a multiresistant agricultural pest that attacks brassica plantations in Brazil and worldwide. The use of natural products with insecticidal properties to control P. xylostella may be advantageous due to the higher degree of degradability and lower persistence of these compounds in the environment when compared with the effects of synthetic insecticides. Moringa oleifera Lam. (Moringaceae) is a pantropical tree that synthesizes proteins (lectins and trypsin inhibitor) whose insecticidal activity has been reported. In the present work, the M. oleifera flower extract containing trypsin inhibitor (MoFTI, M. oleifera flower trypsin inhibitor) was investigated for the presence of peptides resistant to hydrolysis by digestive proteases and effect on survival and protease activity from midgut of P. xylostella third instar larvae (L3). The flower extract showed a high molecular weight polypeptide, which was resistant to hydrolysis by larval gut proteases up to 270 min incubation, revealed by polyacrylamide gel electrophoresis. The larvae were sensitive to the treatment with the extract and the mortality curve revealed a dose dependent response following a polynomial order 2 regression with R2 = 0.99. The maximum mortality rate (60 ± 10%) of larvae was obtained for the extract at 2% (w/v). The adults who emerged from treatment with flower extract showed morphological alterations, including atrophy of the wings and inability to move. In addition, some insects were not able to abandon the cocoon after the end of the pupal phase. The total protease and trypsin-like activities from larval gut were reduced in 67.75 ± 0.64% and 65.83 ± 6.3% by the flower extract at 0.8% and 1%, respectively. Deterrent alimentary effect was not detected when the larvae were reared with cabbage discs treated with the extract at 0.5 and 1%. In conclusion, the M. oleifera flower extract is a larvicidal agent against P. xylostella by cause larval mortality and malformations in adult insects. The larvicidal effect of the flower extract may be linked to the inhibition of enzymes important for the digestive processes of P. xylostella.