Banca de DEFESA: AMANDA MARIA NUNES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : AMANDA MARIA NUNES
DATE: 23/02/2022
TIME: 14:00
LOCAL: Video Conferência
TITLE:

STUDY OF THE CHEMICAL COMPOSITION OF CONVOLVULACEAE SPECIES AND ACARICIDAL EVALUATION ON
Tetranychus urticae KOCH

KEY WORDS:

KEYWORDS: Tetranychus urticae, essential oils, ethanol extracts, acaricidal activity, residual contact.

PAGES: 91
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Química dos Produtos Naturais
SUMMARY:

The Tetranychus urticae Koch known as spider mite causes significant damage to a large number of agricultural crops worldwide. Its control is carried out mainly through the application of commercial insecticides. These insecticides also end up reaching non-target organisms, causing soil contamination in plantations, poisoning in field teams, in addition to being responsible for the emergence of resistant T. urticae populations. Researchers investigate biologically active compounds for the control of agricultural pests, from essential oils and plant extracts. Thus, in the search for a botanical insecticide, five species of Convolculaceae were selected: Distimake aegyptius, Distimake macrocalyx, Ipomoea bahiensis, Ipomoea imperati, and Ipomoea triloba. These species are common in fragments of the Atlantic Forest of Pernambuco. Essential oils (EO) and ethanolic extracts of the five selected species were obtained, and their chemical compositions were analyzed using HPLC-EM techniques. Through the hydrodistillation technique, EO were extracted from leaves and flowers, where 117 and 84 compounds were identified, respectively. The oils revealed in their compositions compounds belonging to the monoterpene and sesquiterpene classes. The major compounds identified in the leaves were: D. aegyptius, (Z)-γ-bisabolene (35.06%), D. macrocalyx, cis-β-guayene, (44.43%), I. bahiensis, (Z)-caryophyllene, (65.02%), I. imperati, limonene, (36.35%) and I. triloba, γ-muurolene, (48.14%). In the flowers, the main compounds were D. aegyptius, (Z)-8-hydroxy-linalool, (26.77%); I. bahiensis, β-funebrene, (59.44%); I. imperati, β-acorenol, (11.87%); and in I. triloba, cis-muurola-4(14),5-diene, (30.73%). The analysis of the leaves extracts was performed by HPLC and GC-MS and showed compounds of the chemical class of terpenoids, phenolic compounds, phenylpropanoids, among others. PCA analysis showed significant differences corresponding to the chemical composition of the EO and extracts of each species. The residual contact acaricide bioassay revealed, after 24h of exposure, low toxicity of leaves EO of the species D. aegyptius and D. macrocalyx, when compared to the positive control used in the Azamax® tests. On the other hand, the estimated LC₅₀ showed toxicity of the ethanolic extracts of D. macrocalyx (17.31mg/mL), I. bahiensis (12.69mg/mL), I. imperati (14.37mg/mL) and I. triloba (5.95mg/mL) against T. urticae.

 

BANKING MEMBERS:
Presidente - 980615 - CLAUDIO AUGUSTO GOMES DA CAMARA
Interno - 1508305 - JOAO RUFINO DE FREITAS FILHO
Externa à Instituição - VANESKA BARBOSA MONTEIRO
Externo à Instituição - JOAO PAULO RAMOS DE MELO
Externa à Instituição - GISELLE BARBOSA BEZERRA