Banca de DEFESA: FRANCISCO CARLOS DE MEDEIROS FILHO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : FRANCISCO CARLOS DE MEDEIROS FILHO
DATE: 20/08/2024
TIME: 15:00
LOCAL: Auditório do Departamento de Química
TITLE:

Chemical composition, insecticidal and acaricidal activity of plant species of the genus Xylopia that occur in Pernambuco

KEY WORDS:

Essential oils; extracts; insecticidal activity; acaricidal activity; antioxidant activity; cytotoxic activity; Plutella xylostella; Tetranychus urticae.

PAGES: 141
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Química dos Produtos Naturais
SUMMARY:

The genus Xylopia presents a great diversity of volatile and fixed chemical compounds of industrial interest due to several biological properties such as antimicrobial, antifungal, antitumor, antioxidant, antibacterial, insecticide activity, among others. Among these compounds we can highlight those belonging to the chemical class of monoterpenes, diterpenes, sesquiterpenes, flavanoids and alkaloids. Plutella xylostella and Tetranychus urticae are agricultural pests responsible for serious damage to several crops of worldwide economic importance such as: tomato, strawberry, papaya, cotton, beans and ornamental plants. The control of these pests has been carried out through the application of conventional insecticides such as Decis® and Orthus®. However, the indiscriminate use of these insecticides has been causing infection of the environment and plantations and allowing survivors to become resistant to their active principles. Thus, an alternative to these conventional insecticides is the use of insecticides of botanical origin (essential oils, extracts or pure compounds) such as those produced by species of the genus Xylopia. For the present work, essential oils and extracts of four species of the Xylopia genus (X. sericea, X. frutescens, X. aromatica and X. brasiliensis) were obtained. The oil was obtained by hydrodistillation and analyzed by gas chromatography and mass spectrometry (GC-MS). The major constituents identified in the essential oils of the leaves of X. sericea were E-caryophyllene (28.46%), germacrene D (22.45%), trans-β-guayene (20.57%), in the leaves of X. frutescens were: myrcene (29.70%), β-pinene (14.31%) and sylvan (10.27%). Regarding the oils from the seeds of X. aromatica, the major constituents were: β-pinene (17.22%), myrcene (13.63%), 1,8-cineol (11.88%) and β-elemene (7.96%). As for the essential oil of the leaves of X. brasiliensis, germacrene D (33.84%), elemol (18.56%), bicyclogermacrene (7.29%), cis-β-guayene (5.00%) were identified. Among the tested oils and extracts, X. sericea oil was considered the most toxic to P. xylostella (LC50 = = 21.05 μl/ml) and T. urticae (LC50 = 16.38 μl/ml) larvae. lowest estimated LC50 value. Among the extracts, X. frutescens was considered the most toxic to P. xylostella larvae (LC50 = 60.51 μl/ml) and T. urticae (LC50 = 11.51). The binary mixtures of essential oil (X. sericea) and pure compound (xylopico acid) showed a synergistic effect for the proportions 9:1 and 7:3 against P. xylostella and for the extracts of X. frutescens and X. aromatica the proportions 9:1 and 6:4 showed strong and moderate synergism, respectively. The oils and extracts were active in the acetylcholinesterase enzymatic pathway. The oils and extracts also showed antioxidant and cytotoxic properties against A. salina L. All essential oils and extracts tested showed moderate or low cytotoxicity against Artemia salina. For the ABTS test, the oil and extract of X. frutescens 67.90 and 62.76 μg/ml and X. aromatic oil with 94.31 μg/ml were the most effective. These preliminary results show that the oils and extracts from the species tested here are promising for their use in the control of Plutella xylostella and Tetranychus urticae.

COMMITTEE MEMBERS:
Presidente - CLAUDIO AUGUSTO GOMES DA CAMARA
Interno - JOAO RUFINO DE FREITAS FILHO
Interno - MARCILIO MARTINS DE MORAES
Externa à Instituição - CAROLINA ALVES DE ARAUJO
Externo à Instituição - MARCILIO WAGNER FONTES SILVA
Externo à Instituição - RODOLFO RODRIGUES DA SILVA - UFRPE