Author(s):
Martins, Vitor Manuel Ramalheira 
; Coimbra, Manuel A.
Date: 2012
Persistent ID: http://hdl.handle.net/10198/8154
Origin: Biblioteca Digital do IPB
Subject(s): Polysaccharides; Infusions; Fraxinus angustifolia
Description
In folk medicine there is a great variety of plants that are used for as infusions, such as Camellia
sinensis and Matricaria recutita. Despite the reported biological activities and health benefits of
these infusions [1,2], most of the knowledge achieved so far is based on folk tradition passed
over several generations, without a sound scientific basis.
In Trás-os-Montes region, the dried leaves of the narrow-leafed ash “freixo” (Fraxinus
angustifolia) are used for medicinal purposes, particularly against high levels of cholesterol,
blood pressure and uric acid [3]. These health benefits are associated with the presence of
biologically active compounds such as phenolic compounds, essential oils, and polysaccharides,
among others. Although phenolic compounds and essential oils have been studied in detail for
more than two decades, the structures of the polysaccharides present in plant infusions and their
involvement in the health benefits is still incipient. Therefore, in this work we present a study
regarding the structure of the polysaccharides present in the infusions of “freixo” dried leaves.
“Freixo” leaves were collected and dried according to the popular tradition and used for the
preparation of the infusions. The polysaccharides were recovered by dialysis, fractionated by
ethanol precipitation and anion exchange chromatography, yielding fractions with distinct
ethanol solubility and uronic acid content. Sugar and linkage analysis evidenced the presence of
pectic polysaccharides, frequently reported as immunostimulatory active [4]. The assessment of
the biological activity of these fractions is in progress.
