Name: ALESSANDRO BERMUDES GOMES
Type: PhD thesis
Publication date: 20/03/2020
Advisor:

Name	Role
Viviana Borges Corte	Advisor *

Examining board:

Name	Role
Camilla Rozindo Dias Milanez	Advisor *
Carine Coneglian de Farias Colman	External Alternate *
Elias Terra Werner	Internal Examiner *
Hildegardo Seibert França	Co advisor *
Janaína Brandão Seibert	External Examiner *
Valéria de Oliveira Fernandes	Internal Alternate *
VITOR DE LAIA NASCIMENTO	External Examiner *
Viviana Borges Corte	Advisor *

Summary: Geonoma schottiana Mart. is a native plant of the Atlantic Forest and it shows few
studies on its biological and phytochemical potential. Therefore, this study aimed at
bioprospecting of the G. schottiana leaves, evaluating its allelopathic, antioxidant,
photoprotective potential and the phytochemical constitution of the ethanolic extract
and its fractions (hexane, dichloromethane, ethyl acetate and butanol). The allelopathic
activity was developed through biological tests with analysis of the germination
variables and the initial growth, in which the hexane and butanol fractions showed the
best results, as they potentiated the germination and growth variables on the lettuce
and sensitized the colonio grass. The analysis of the hexane and butanol fractions at
a concentration of 1.0 mg / mL promoted an increase in the activity of the antioxidant
enzymes Catalase (CAT), Peroxidase (POX) and superoxide dismutase (SOD)as well
as lipid peroxidation (MDA) on seed and roots of colonio grass. The contents of
phenolic compounds and total flavonoids were evaluated by the Folin-Ciocalteau and
aluminum chloride methods, respectively, while the tannins were determined by the
casein precipitation method. The antioxidant activity was determined by ABTS, DPPH,
FRAP, TAC-Phosphomolybdenum assay. The analysis of ABTS redox activity
increased in the butanol fraction, as well as in the DPPH in the ethyl acetate and
dichloromethane fractions and in the FRAP for the dichloromethane fraction, compared
to the trolox equivalent (µMol Trolox / g of the extract). The TAC-Phosphomolybdenum
assay was significant for the hexane and dichloromethane fractions compared to
ascorbic acid equivalents (µg EAA g-1). Phytochemical prospecting was performed by
thin layer chromatography (CCD), high performance liquid chromatography (HPLC)
and gas chromatography-mass spectrometry (CG/EM). steroids, lignin, mono and
diterpenes, alkali and flavonoids were identified in phytochemical prospecting by CCD
for the hexane and butanol fractions. The HPLC analysis demonstrated the presence
of chlorogenic acid in the crude extract and hyperoside in the ethyl acetate fraction,
with the patterns isoquecertine, mirecithin and rutin found in the ethyl acetate and
butanol fraction. The CG/EM of the hexane and dichloromethane fractions
demonstrated the presence of phytol, a precursor to vitamin E. The photoprotection
factor of the ethanolic extract and its fractions was evaluated, and the hexane fraction
obtained the best result for the sun protection factor (6.39). In summary, the results
obtained in this work indicate that the ethanol extract from G. schottiana leaves and
its fractions have potential as a source of compounds with allelopathic, antioxidant and
photoprotective activities.
Keywords: Allelopathy. Bioprospecting. Germination. Antioxidants.