Aromatic plants from the Plateau des Cataractes (Congo Basin). Chemotype characterization of essential oil of Cymbopogon nardus (L.) Rendle acclimatized in Congo-Brazzaville

Description. The essential oils of Cymbopogon nardus (L.) Rendle, Cymbopogon winterianus Jowitt, Cymbopogon flexuosus (Nees ex Steud.) Wats and Cymbopogon citratus L. (DC.) Stapf (lemongrass) consist of more than 80% of the following constituents: citronellal, geraniol, citral, citronellol, geranyl acetate, and limonene. For the purposes of business transactions, it is therefore important to know the exact chemical composition of the essential oils produced. Objectives. Chemotype evaluation of C. nardus acclimatized on the Plateau des Cataractes. Method. The essential oils of C. nardus were extracted by hydrodistillation and analyzed by chromatography (GC and GC/MS) over a period of more than ten years. Results. Cymbopogon nardus was found to produce a Java type citronella essential oil (C. winterianus) with the following profile: citronellal (40-48%), geraniol (10-22%), citronellol (10-12%), limonene (2-3%), geranyl acetate (1-2%), linalool (1%). The difference between these two types of citronella, Java and Ceylon, was based on the relative proportions of their three main constituents: citronellal, geraniol and citronellol. Cymbopogon nardus is known for its high variability, with two varieties and seven subvarieties. Conclusions. The citronella established in West and Central Africa under the name of Cymbopogon nardus (Java type) could be considered a Cymbopogon winterianus Jowitt, based on the chemical composition of its essential oil.