Banca de QUALIFICAÇÃO: LUANA CRISTINA DINIZ SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LUANA CRISTINA DINIZ SANTOS
DATE: 04/03/2022
TIME: 09:00
LOCAL: Plataforma Google Meet
TITLE:

Phytochemical study and evaluation of antioxidant and larvicidal activities of seeds of Handroanthus impetiginosus (Mart. ex Dc.) Mattos (Bignoniaceae)

KEY WORDS:

Ipê-roxo, fatty acids, fatty acid methyl esters, antioxidants, Artemia salina, Culex quinquefasciatus.

PAGES: 55
BIG AREA: Ciências Biológicas
AREA: Botânica
SUMMARY:

Handroanthus impetiginosus (Mart. ex Dc.) Mattos (Bignoniaceae), popularly known as purple ipê is a seasonal forest species that can be found in some Brazilian biomes. It has great economic importance, due to its use in civil and naval constructions, ecological importance, in the recovery of forest ecosystems, and also medicinal importance, for its bioactive compounds. The objectives of this work were to obtain fatty acids and fatty acid methyl esters from the hexane extract of H. impetiginosus seeds and to evaluate the antioxidant and larvicidal activities against Artemia salina and Culex quinquefasciatus of the hexane extract (HE), of the fatty acids ( AG) and fatty acid methyl esters (FME). The HE was obtained by extraction in a Sohxlet apparatus and phytochemical screening was performed. The FA were obtained by hydrolysis of the triglycerides present in the hexane extract, by a strong base, for 30 and 60 minutes and the EMAG were produced through the transesterification reaction of fatty acids by acid catalysis. The composition of fatty acids and fatty acid methyl esters was determined by gas chromatography coupled to mass spectrometry. The antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method and the larvicidal activity was tested against Artemia salina and Culex quinquefasciatus. The results showed that the EH presented a yield of 20.47%, with the presence of alkaloids, according to the phytochemical screening. Fatty acids were obtained through hydrolysis for 30 (AG30) and 60 minutes (AG60) of the triglycerides present and methyl esters of fatty acids (EMAG 30 and EMAG60), and for the GA there was a higher yield of GA30 ( 44.95%), while for EMAG, higher yield was verified for EMAG60 (35.96%). In the hexane extract, three FAs (palmitic, linoleic and oleic acids) were identified, with oleic acid being the major constituent (10.08%) and five ethyl esters of fatty acids, four of which were the majority, with predominance of ethyl oleate (34 .93%). The EMAG30 mixture consisted of ten methyl esters and EMAG60 presented a mixture of eight methyl esters, with the major compounds in both samples represented by methyl palmitate, methyl linoleate, methyl oleate and methyl stearate, with predominance of methyl oleate (28.70% and 30.44%, respectively). The EH, AG30, AG60, EMAG30 and EMAG60 samples showed antioxidant activity below 50%, compared to the BHT standard, which showed inhibition above 90% at concentrations of 250 and 500 µg/mL and 86% at the concentration of 100 µg/ml (P < 0.0001). At concentrations from 1 to 10 µg/mL there was a slight reduction in the antioxidant activity of the samples, however, these activities were higher than that observed for the BHT standard. Samples AG30, AG60, EMAG30 and EMAG60 showed significant toxicity against A. salina at a concentration of 1000 µg/mL (P < 0.0001). AG60 was the sample that showed the greatest toxic effect against A. salina, promoting 100% mortality at all concentrations tested (125 to 1000 µg/mL) (P < 0.0001). All samples tested caused a high mortality of C. quinquefasciatus larvae, regardless of the concentration used (P < 0.0001). The data found so far encourage the performance of new tests to confirm the results found and also to detect other biological activities.

BANKING MEMBERS:
Presidente - 395916 - ANA HORTENCIA FONSECA CASTRO
Interna - 1540495 - LUCIANA ALVES RODRIGUES DOS SANTOS LIMA
Externa à Instituição - PAULA AVELAR AMADO - UFSJ
Externo à Instituição - ADRIANO GUIMARAES PARREIRA - UEMG