Chemical analysis of essential oils of malagasy medicinal plants by gas chromatography and NMR spectroscopy

Abstract

Abstract In Collaboration with the Institut Malgache de Recherches Appliquées, Antananarivo, the composition of the essential oils of medicinal plants indigenous to or cultivated in Madagascar was determined. The aim of the study was the evaluation of these plants for their possible safe use in many products of wide consumption such as foodstuffs, pharmaceuticals or cosmetics. Analyses were performed coupling the data obtained by capillary gas chromatography and 1 H‐ and 13 C‐NMR techniques. The 13 C‐NMR spectroscopy proved to be an important tool, which can be very useful in the identification of main constituents, whereas only partial indications can be obtained for minor components. The results of the analyses of the essential oils of commercial plants ( Cinnamomum camphora Nees and Eberm., Cinnamomum zeylanicum Breyn., Eucalyptus citriodora Hook, Eucalyptus globulus Labill., Eucalyptus spp., Melaleuca viridiflora Soland. ex Gaertn., Ocimum gratissmium L.) and endemic species (i.e., Helichrysum gymnocephalum Humbert, Priadia goyavia Berger, Ravensara anisata Danguy and Choux) are reported. Some antibacterial activities against Escherichia coli of the essential oils are also reported.