Aromatic plants of tropical West Africa. XI. Chemical composition, antioxidant and antiradical properties of the essential oils of three Cymbopogon species from Burkina Faso

The essential oils isolated by hydrodistillation from the leaves or the flowering stalks of Cymbopogon citratus (DC) Stapf., C. giganteus Chiov. and C. proximus Stapf. syn. C. schoenanthus (L.) Spreng. subsp. proximus (A. Rich.) Maire & Weiller from Burkina Faso were analyzed by GC and GC/MS. The main constituents of the oil of C, citratus were geranial (44.6%), neral (33.0%) and myrcene (10.7%). The oil of C. giganteus contained limonene (17.3%) and a set of monoterpene alcohols: trans-p-mentha-1(7),8-dien-2-ol (17.0%), cis-p-mentha-1(7),8-dien-2-ol (16.5%), trans-p-mentha-2,8-dien-1-ol (13.8%) and cis-p-mentha-2,8-dien-1-ol (9.3%). The main component of the leaf and flower oils of C. proximus was piperitone ((59.1%) and 55.6%, respectively). The essential oils of the three Cymbopogon species were also studied concerning their antioxidant and antiradical activity. Their properties were very low, compared to the two commercially used antioxidants tested (BHT and delta-tocopherol). C. proximus showed the strongest antioxidant activity (Antioxidant Value = 1.54), followed by C. giganteus (A.V. = 1.04) and C. citratus (A.V.=0.11). On the other hand, the oil of C. citratus was estimated to present the highest antiradical power, followed by C. proximus and C. giganteus.