Aislamiento e identificación de metabolitos secundarios de las hojas y flores de Gaiadendron punctatum (violeta de campo) G.Don. utilizada como especie medicinal por la comunidad indígena Saraguro en el sur del Ecuador.

Abstract

It was performed the isolation and characterization of secondary metabolites present in Gaiadendron punctatum, used by Saraguro culture in the province of Loja (Ecuador), in the healing of various diseases, especially related to the respiratory tract. The research started with the collection of the species in the Saraguro canton. The flowery botanical specimens were dried, weighed and leaves and flowers were classified. The extract was obtained by succesive maceration with solvents or mixture of different polarity: Leaves (hexane, ethyl acetate, methanol, methanol:water (7:3) and ethanol) and flowers (hexane, ethyl acetate and methanol). The richest extracts by TLC analysis (ethyl acetate and ethanol in leaves and hexane and methanol in flowers) were fractionated by column chromatography. The resulting fractions were purified by preparative chromatography, microcolumns and 17 secondary metabolites were isolated, 15 of them different. The structural elucidation was performed with the techniques of GC-MS and NMR, allowing the identification of lupenone and lupeol triterpenes, the plant sterol β-sitosterol, the glycosylated flavonoid artubotryside A and a serie of quercetin and kaempferol glycosilated flavonoids.