Comparative Essential Oil Composition and Antioxidant Activity of Flowers, Leaves and Stems of Rose-Scented Geranium (Pelargonium graveolens L'Her.) from Tunisia

The chemical composition of the essential oils of flowers, leaves and stems from rose-scented geranium (Pelargonium graveolens L'Her.) have been examined by GC-MS. The main constituents of the essential oil of flower, leaves and stem oils, respectively were: beta-citronellol (20.94, 16.24 and 12.72%), geraniol (13.53, 15.30 and 10.39%), citronellyl format (10.54, 7.39 and 7.47%) and geranyl formate (6.75, 6.47 and 7.33%). The delta-selinene (13.62%) was identified as the highest main constituent, while the gamma-eudesmol is absent in stem oil. For the evaluation of the antioxidant activity, two different methods were employed: the 2,2-diphenyl-1-picrylhydrazyl radical scavenging method (DPPH) and ferric reducing antioxidant power assay (FRAP). These two methods showed that essential oils of flower, leaves and stems possessed antioxidant property comparable with that of the acid ascorbic and butylated hydroxytoluene (BHT).