Banca de QUALIFICAÇÃO: ADRIANO LOPES DA SILVA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ADRIANO LOPES DA SILVA
DATE: 16/09/2021
TIME: 14:00
LOCAL: Campus Centro Oeste Dona Lindu
TITLE:

CHEMICAL COMPOSITION AND EVALUATION OF THE ANTIOXIDANT AND LARVICIDE ACTVITIES OF THE EXTRACTS, FATTY ACIDS AND METHYL ESTERS OF THE FRUIT OF Tecoma stans (L.) Juss. Ex Kunth (BIGNONIACEAE). 

KEY WORDS:

Tecoma stans, insecticide, antioxidant activity, larvicidal activity, Culex quinquefasciatus.

PAGES: 59
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

Antioxidants are of great benefit in improving people's quality of life, as they have the ability to protect an organism from damage caused by free radicals. There is a growing interest in antioxidants from plant extracts from aromatic and medicinal plants, cereals, fruits, considered sources of natural antioxidants, which can prevent or prevent pathologies. Thus, it is economically interesting to invest in strategies that prevent the incidence of diseases, as well as in effective and low-cost treatments. The Culex quinquefasciatus mosquito is a vector of several pathogens to man, being characterized as of high importance in public health, a nuisance factor in numerous urbanized areas of Brazil, of undesirable presence and constituting a decrease in people's quality of life, justifying its control in infested areas. The creation of the insecticide dichlorodiphenyltrichloroethane (DDT), followed by carbamates and pyrethroids, was a historic and economic milestone in insect control. These synthetic insecticides cause great environmental impact and, consequently, also to public health, because they are not biodegradable and because they are bioaccumulative. Due to these factors, it is important to search for new, more effective insecticides. Ipê-mirim, guarã-guarã, Ipê-de-jardim, amarelinho and yellow carob are some of the names by which the species Tecoma stans (L.) Juss is known. Ex Kunth, which belongs to the Bignoniaceae family, is considered an invasive plant in Brazil. Little is known about this species in Brazil, but the presence of potentially bioactive substances such as flavonoids, tannins, alkaloids, quinones and iridoids is known. This study aimed to evaluate the antioxidant activities and larvicidal potential of T. stans fruit from hexane and methanol extracts, their fatty acids and methyl esters. The extracts were obtained with hexane and methanol in a Sohxlet apparatus. The extracts were hydrolyzed and esterified to obtain fatty acids and methyl esters, respectively, which were analyzed by Gas Chromatography to determine their chemical composition. In the phytochemical screening, the presence of steroids, triterpenes, alkaloids and coumarins for EH was detected, whereas for EM only the presence of alkaloids and coumarins was verified. In the analysis by GC-MS, it was identified as the majority compound (81.69%) in the hexane extract, the nonacosane hydrocarbon. In the analysis of FAME, it was observed that the proportion of saturated esters (36.37%) was higher than those of unsaturated (42.27%) in the hexane extract. In the methanol extract, the proportion of saturated esters was 76.97% and that of unsaturated was 22.99%. In the FAME fo hexane extract, the major compounds were methyl hexadecanoate or methyl palmitate (C16:0), methyl  9, 12-octadecadienoate or methyl linoleate (C18:2) and methyl 9, 12, 15-octadecatrienoate or methyl linolenate (C18:3). In the FAME of methanol extract, the major compound was methyl hexacosanoate (C26:0). In evaluating the antioxidant activity, the samples were effective at all concentrations tested (1, 10, 100, 250 and 500 µg/mL), with high antioxidant potential, with percentage inhibition ranging from 63.70 to 96.10% at the concentration of 500 µg/mL. The samples were more effective than BHT in capturing DPPH radicals, because they had lower EC₅₀ values. The results for lethality in A. salina showed that the FAME from the hexane extract and the FAME from the methanol extract can be considered toxic with LD₅₀ < 1000 µg/mL, and also, the FAME from the methanol extract can present anti-Tripanosoma cruzi and antitumor. Thus, it can be concluded that this work is important because it contributes to the identification of compounds present in the fruits of T. stans, as well as to the evaluation of the biological activities of this species.

BANKING MEMBERS:
Presidente - 1540495 - LUCIANA ALVES RODRIGUES DOS SANTOS LIMA
Externa à Instituição - NATHÁLIA LUCCA SILVA - UNA
Externa à Instituição - MELISSA GRAZIELLE MORAIS - UEMG
Externo à Instituição - MAIRON CESAR COIMBRA - UFSJ
Externo à Instituição - ADRIANO GUIMARAES PARREIRA - UEMG