Isolation and characterization of polysaccharides from Fraxinus angustifolia infusions

• 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
• Document Type: Conference object
• Language: English
• Contributor(s): Biblioteca Digital do IPB

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.