Ponencia
Antibacterial activity of alkaloids extract from Rhodophiala araucana (Amaryllidaceae)
Fecha
2017Institución
Resumen
The Amaryllidaceae family has been largely mentioned in the use of traditional medicine. A
particular characteristic of this family is the presence of a large group of isoquinolinic alkaloids,
most of them absent in any other plant family. Currently, more than 500 alkaloids have been
isolated from plants from Amaryllidaceae, and although their structures vary considerably, these
alkaloids are related biogenetically. The resistance of microorganisms against antibiotic is a
permanent incentive to search for antimicrobial agents from natural sources. In this sense, plants
of the Amaryllidaceae family are characterized for a wide range of biological activities, including;
antiviral, antibacterial, antiparasitic, psychopharmacological, among others. The aim of this work
was to evaluate the antibacterial activity of alkaloids extract obtained from Rhodophiala araucana
bulbs against Gram-negative and Gram-positive bacteria and identify the alkaloids presents. The
bulbs of R. araucana were obtained from the Tolhuaca National Park (IX region, Chile) in
December 2016. The dried bulbs (138 g) were crushed and macerated with MeOH (3 x 2 L), the
macerate was filtered and evaporated to dryness. The crude extract was acidified to pH 2 with
H2SO4, neutral materials were removed using Et2O and CHCl3. The aqueous phase was basified up
to pH 9 with NH4OH (25% v/v) and extracted with n-hexane, CHCl3, AcOEt:MeOH (3:1) and n-
BuOH. The antibacterial activity was performed by disc diffusion method and the alkaloids
composition by gas chromatography-mass spectrometry. Chromatographic analysis of the extracts
showed the presence of the isoquinolinic alkaloids, highlighting the presence of alkaloids of the
type Tazettine, Galanthamine and Lycorin. The results showed antibacterial activity of the butanol
extracts against Gram-positive bacteria.