Chemical composition and antioxidant activity of Acacia polyphylla (Fabaceae)

Abstract

This work describes the phytochemical study of the ethanol extract from the leaves of Acacia polyphylla, leading to the isolation and identification of five flavonoids (luteolin, isovitexin, quercetin 3-O-β-D-glucopyranoside, quercetin 3-O-β-D-galactopyranoside and vitexin-2”-O-rhamnoside), three triterpenes (α-amirin, β-amirin and lupeol), four steroids (stigmast-22-en-3β-ol, spinasterol, sitostanol and β-sitosterol) and an alkane (n-nonacosane). All compounds were identified by a combination of spectroscopic methods (1H and 13C NMR, including 2D, and UV), GC-MS, UPLC-DAD-ESI-QTOF-MS/MS and comparison with the literature data. Antioxidant activity, the total phenol content, the total flavonoid content and the scavenging activity against free radical DPPH were also evaluated. The ethyl acetate fraction presented the best result with EC50 value of 7.78 ± 0.17 μg.mL-1 and total phenol and total flavonoid contents with values of 563.28 ± 1.13 GAE.g-1 and 217 ± 0.17 QE.g-1, respectively, suggesting the potential of A. polyphylla as a source of antioxidants.