2013 - Maísa Almeida Leite
MSc. Thesis
Author: Maísa Almeida Leite
Postgraduate Program in Pharmaceutical Sciences - State University of Maringá
Area of Knowledge: Pharmacognosy
Date of Defense: December 17, 2010
Advisor: Prof. Dr. João Carlos Palazzo de Mello
Examination Board: Prof. Dr. Cleyton Eduardo Mendes de Toledo
Prof. Dr. Graciette Matioli
Title: Isolation and structural identification of polyphenols in Stryphnodendron adstringens (barbatimão)
Abstract: Stryphnodendron adstringens, known as “barbatimão”, is used as a medicinal plant by the population and it is found in the Brazilian savannah (cerrado). The extracts from the bark of this plant have high tannin content. Several compounds were isolated and identified, like flavan-3-ols, prodelphinidins and prorobinetinidins. Studies with the species proved the follow activities: antimicrobial, antiviral, wound healing, antiulcer, antioxidant, anti-inflammatory, and antileishmanial. This work aimed the isolation and structural identification of polyphenols of ethyl acetate semipurified fraction obtained from the stem barks ofStryphnodendron adstringens using different chromatographic methods, such as column chromatography (CC), high-speed counter-current chromatography (HSCCC), preparative thin layer chromatography (Prep-TLC), medium-pressure liquid chromatography (MPLC) and high-performance liquid chromatography (HPLC). The identification was performed by spectroscopic methods of nuclear magnetic resonance (NMR) 1D (1H and 13C), 2D NMR (1H-1H COSY, HSQC and HMBC). Compounds were identified as 4′-O-methylgallocatechin, gallocatechin, epigallocatechin, epigallocatechin-3-O-galate, 4′-O-methylgallocatechin-(4α→8 -4′-O-methylgallocatechin, 4′-O-methylrobinetinidol-(4α→8 -4′-O-methylgallocatechin, epigallocatechin-(4β→8 -epigallocatechin-3-O-galate, epigallocatechin-(4β→8 -epigallocatechin-3-O-(4-hidroxi)-benzoate. In addition, it was isolated by the first time 4′-O-methylepigallocatechin, epigallocatechin-3-O-gallate-(4β→8 -gallocatechin, gallocatechin-(4α→8 -epigallocatechin and epigallocatechin-3-O-galate-(4β→8 -epigallocatechin in this species. Thus, knowledge of the chemical constituents of S. adstringens can promote information concerning the characterization of the species and explain, at least in part, the pharmacological activities of the plant.
Keywords: Stryphnodendron adstringens, condensed tannins, chromatographic methods
Dissertation PDF: Maísa Almeida Leite
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