Banca de DEFESA: ANDREA CARLA DE ALMEIDA BARROS

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ANDREA CARLA DE ALMEIDA BARROS
DATE: 05/08/2022
TIME: 14:00
LOCAL: meet.google.com/ayd-ebst-hfp
TITLE:

Evaluation of the insecticidal activity of the stalk of Guadua angustifolia Kunth against Tribolium castaneum (Herbst)

KEY WORDS:

Bamboo; purification; lectin

PAGES: 116
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:

Tribolium castaneum, an insect belonging to the order Coleoptera, is an important agent that causes great economic damage to
grain stored in South America. To control this pest, more efficient methods are sought, less toxic to the environment and compatible
with the volume of stored. Extracts and lectins isolated from plants have shown insecticidal properties to different orders of insects
and for this reason have been studied by several research groups. Brazil has the largest native bamboo forest diversity in the
Americas. Among the identified species, Guadua angustifolia is a fast-growing grass that offers raw materials explored in the areas
of landscaping and civil construction. Thus, the present study aimed to analyze the effect of extract and lectin isolated from the stem
of G. angustifolia in adult insects of T. castaneum. For this, the crude extract was prepared in 50 mM Tris-HCl, pH 8.0 of the sprayed
bamboo stem. Subsequently, phytochemical analysis, protein quantification, and identification of the presence of lectin was
performed. The antioxidant potential of the extract was evaluated. Then, the extract (25 mg, 50 mg and 100 mg) was evaluated for
insecticidal activity, analyzing the nutritional parameters and survival rate of the insects treated during the 30-day bioassay. To isolate the lectin from G. angustifolia (GaL), it was proposed to treat the crude extract with ammonium sulfate, followed by chitin column
chromatography. GaL was evaluated by denaturing electrophoresis (SDS-PAGE). The extract showed important secondary
metabolites such as the presence of flobafenic tannins, flavones, flavonols, xanthones, flavonones, steroids and saponins, as well
as the sample showed an increase in the percentage of sequestration of the radical DDPH, with an increase in the concentration of
the sample (100 - 700 mg / ml). The extract at 50 mg showed a mortality rate of 50% of insects from T. castaneum, presenting a
deterrent activity (50 and 100 mg) in addition to exerting anti-nutritional effects on the conversion of biomass and insect growth. GaL
was isolated after eluting the chitin column with 1 M acetic acid, presenting itself as a protein with 18.4 kDa with hemagglutinating
activity inhibited by N-acetylglycosamide, maltose and fetuin. Thus, aqueous preparations of stem of G. angustifolia containing lectin
showed potential insecticide for the population control of T. castaneum.

BANKING MEMBERS:
Externa à Instituição - ADRIANA DE LIMA MENDONCA - NENHUMA
Presidente - 2089586 - FRANCIS SOARES GOMES
Externa à Instituição - JANAÍNA KÍVIA ALVES LIMA - Outros(as)
Interna - 1294906 - RUTH RUFINO DO NASCIMENTO
Externa ao Programa - 166.228.474-87 - SONIA SALGUEIRO MACHADO - UFAL