Banca de DEFESA: NATAN RODRIGUES SANTANA DA HORA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : NATAN RODRIGUES SANTANA DA HORA
DATA : 16/11/2020
HORA: 09:00
LOCAL: https://conferenciaweb.rnp.br/spaces/defesa-de-dissertacao-natan-rodrigues-pmbqbm
TÍTULO:

Metabolite profiling, antioxidant, cytotoxic and antimicrobial activities of extracts of the stigma of Zea mays L. 

PALAVRAS-CHAVES:

 Corn silk, Metabolomics, Natural Products.

PÁGINAS: 87
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:

INTRODUCTION: The stigma of corn is the female flower of Zea mays L., well known for traditional Chinese medicine. The scientific literature reports its pharmacological activities, but there are few scientific studies that perform a global chemical mapping, and correlate metabolites with the investigated biological activities, by means of a metabolomic. OBJECTIVE: To characterize the metabolomic profile and the antioxidant, antimicrobial and cytotoxic activities of extracts of the stigma of Zea mays L. in natura and its commercial product. MATERIALS AND METHODS: The extracts were obtained from the stigma of corn, by maceration in different solvents, such as hexane, ethyl acetate and ethanol. The antioxidant activity was provided by the 2,2-diphenyl-1-picryl-hydrazyl free radical sequestration method (DPPH) and the total phenols were quantified by the Folin-Ciocalteu method. The antimicrobial activity was evaluated by the microdilution method in broth against Gram-positive and Gram-negative bacteria, besides non filamentous fungi. The cytotoxicity was evaluated against a tumoral line of mouse glioma (C6), through the analysis of the cellular viability evaluated by the method of 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium (MTT) bromide reduction. The metabolic profile was evaluated by high efficiency liquid chromatography coupled to mass spectrometry (CLAE-EM) and gas chromatography coupled to mass spectrometry (CG-EM). In the univariate analysis, analysis of variance (ANOVA), volcano plotting and correlation analysis were used. In multivariate analysis the methods were PLS-DA, VIP and heat map. In general, the ethanolic extracts present better antioxidant activity and higher values of total phenols. RESULTS AND DISCUSSION: The antioxidant activity (IC50) varied from 77.44 μg.mL-1 for the ethanolic extract of reproductive stage 1 (E1R1) to 950, 31 μg.mL-1 for the hexanic extract of commercial product (CH). Total phenol values ranged from 12, 95 mg.EAG.g-1 for ethanolic extract of commercial product to 46, 14 mg.EAG.g-1 for ethanolic extract of reproductive stage 1. The extract with ethyl acetate reproductive stage 1 (EAR1) showed better antibacterial activity against Bacillus subtilis and Pseudomonas aeruginosa (500 μg.mL-1). The EAR1 extract presented higher cytotoxic activity, because it was able to reduce the viability of the C6 tumor lineage (100 μg.mL-1 ) by 40.74%. Thirty metabolites were identified. The organic acids, carbohydrates and a saponin have greater correlation with the antioxidant activity; cytotoxic and antimicrobial. CONCLUSION: Although some studies present the biological activities of Zea Mays L. extracts, this was the pioneer in presenting an overall metabolic evaluation of extracts with different polarities and correlating the results of antioxidant, cytotoxic and antitumicrobial activities with the metabolites located in the extracts. In addition, the influence of solvents, phenological stages and natural and commercial nature on the variation of the metabolome were identified and suggesting the main metabolites responsible for influencing greater biological activities.

MEMBROS DA BANCA:
Presidente - 3768242 - PAULO ROBERTO RIBEIRO DE JESUS
Externo à Instituição - DÉBORAH YARA ALVES CURSINO DOS SANTOS - USP
Externo à Instituição - LOURDES CARDOSO DE SOUZA NETA