2016 - Leila Larisa Medeiros Marques
Ph.D. Thesis
Author: Leila Larissa Medeiros Marques
Postgraduate Program in Pharmaceutical Sciences - State University of Maringá
Area of Knowledge: Pharmacognosy
Date of Defense: November 11, 2016
Advisor: Prof. Dr. João Carlos Palazzo de Mello
Examination Board: Prof. Dra. Sandra Regina Salvador Ferreira
Prof. Dr. Benício Alves de Abreu Filho
Prof. Dra. Denise Brentan da Silva
Dra. Sandra Mara Antonelli Ushirobira
Title: Phytochemical and biological research of extracts obtained by supercritical technology from Paullinia cupana seeds (guaraná).
Abstract: Paullinia cupana H. B. K. var. sorbilis (Mart.) Ducke, known as guaraná, is a native Brazilian plant. The seeds contain high concentrations of methylxanthines, saponins, and polyphenols, particularly tannins. The pharmacological it is assigned several functions such as a stimulant, astringent, analgesic, febrifuge, antimicrobial, antioxidant, panicolytic, antidepressant, protective of the gastrointestinal tract and DNA, for treating hypertension, chronic diarrhea, migraine, and neuralgia. This work was concerned to prepare a review article about guaraná, focusing on the versatility of these pharmacological functions. It also presented the current scenario of this plant, besides providing new topics as quality control and standardization of plant drug and its extracts. Additionally, this study aimed to apply the supercritical technology, optimizing the extraction of bioactive compounds from guaraná seeds, investigating its antioxidant, antimicrobial activities, and chemical profile. Supercritical extraction of bioactive compounds of guaraná seeds was carried out and planned using an orthogonal matrix (OA9(34)). The factors and levels studied were: modifier (s) (ethanol and / or methanol), extraction times (20, 40, and 60 min), temperature (40, 50, and 60 °C), pressure (100, 200, and 300 bar). Carbon dioxide was used as the supercritical fluid, together with different proportions of modifiers (10, 20, and 40%), defined as experiment X, Y, and Z, respectively. The best conditions for the supercritical extraction, based on the content of polyphenols, epicatechin/catechin quantification, yield, and operating cost, proved to be: 40% ethanol:methanol during 40 min, at 40 °C, and 100 bar. The percentage of modifier used was proportional to the amount of polar compounds extracted. The most of the extracts from the experiment Z showed promising antimicrobial activity (31.25 mg L-1) against the strain of methicillin-resistant Staphylococcus aureus. In qualitative tests, the hexane fraction of the extract 3 (ethanol:methanol 40%; 40 min; 40 ºC, and 300 bar) showed antimicrobial activity against Candiada tropicalis strains, S. aureus and Lactobacillus fermentum. The extracts 1 (ethanol, 20 min, 40 °C, and 100 bar), 2 (methanol, 60 min, 40 °C, and 200 bar), and 8 (methanol, 40 min, 60 °C, and 100 bar) from the experiment Z showed highest combined values of antioxidant activity by DPPH, Frap, ABTS methods, and xanthine oxidase system. Chemical analysis of extracts from experiment Z showed similar profiles, as analyzed by HPLC-DAD-MS. In addition to caffeine, the main compound extracted, extracts containing epicatechin, catechin, theophylline, theobromine, and dimers and trimers proanthocyanidin type A and B. The heat map analysis showed a positive correlation between the antioxidant methods (DPPH, Frap, and ABTS), and with catechin, epicatechin, and procyanidin type B.
Keywords: Paullinia cupana, supercritical extraction, orthogonal matrix, modifier.
Thesis PDF: Leila Larissa Medeiros Marques
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