Antioxidant Activity of Selected Chemical Constituents of Quinchamaliumchilensis
Antioxidant compounds from plant sources have been used worldwide for a variety of indications. In this study, phytochemical investigation of the aerial parts of QuinchamaliumchilensisMol. (Santalaceae) resulted in the isolation and identification of fourflavonol glycolsides, quercetin-3-O-β-D-glucopyranosyl-(1→2)-[α-L-rhamnopyra-nosyl-(1→6)]-β-D glucopyranoside(1), kaempferol-3-O-β-D-glucopyranosyl-(1→2)-[α-L-rhamn opyranosyl-(1→6)]-β-D-glucopyranoside(2),quercetin-3-O-xylosyl-(1→2)-[α-L-rha-mnopyranosyl-(1→6)]-β-D-glucopyranoside(3) and rutin(4), as well as one flavanone glycoside, pinocembroside(5). The compounds were identified by 1D- and 2D-NMR experiments, mass spectrometry and UV spectra by comparison with those reported in literature. These compounds were isolated for the first time from the leaves of Q. chilensis. The antioxidant properties of the extract were investigated using DPPH and ferric reducing antioxidant potential (FRAP) assays. Total phenolic content was determined by the Folin-Ciocalteau method. Significant relationship between antioxidant capacity and total phenolic content was found, indicating that phenolic compounds are the major contributors to the antioxidant properties of this plant. These active molecules have therapeutic potential in treating conditions associated with oxygen free radicals.