Moringa oleifera leaves: LC-ESI-MS analysis of phenolic compounds and antioxidant activities

Research on bioactive compounds derived from medicinal plants is still topical and their applications are of interest to food industry, phytopharmacy and cosmetics. The present study deals with the phenolic compounds profile and antioxidant activities of Moringa oleifera Lam. leaves. Therefore, this work is a contribution to study the potential of M. oleifera as a new crop in Tunisia. Composition of phenolic compounds was realized using LC-ESI-MS analysis. Antioxidant activities were assessed using many complementary methods. Extracts from Moringa leaves contained interesting amounts of total phenolics (33–99 mg GAE/g extract) and flavonoids (7–18 mg QE/g extract), with appreciable antioxidant activities in Fe3+ reducing (EC0.5: 0.5–1.1 mg/ml), DPPH• radical-scavenging (IC50: 0.6–1.9 mg/ml), β-carotene/linoleic acid bleaching (IC50: 66–120 µg/ml) and Fe2+ chelating (IC50: 0.5–0.8 mg/ml) assays. Quinic acid, gallic acid, quercetin-3-O-galactoside and quercetin-3-O-rhamnoside were the major compounds measured in the different extracts (5.5–13.5 mg/g extract). M. oleifera grown in oasis of Chenini-Gabes, southeastern Tunisia, can be a source of potent antioxidants for various food, nutraceutical or cosmeceutical applications