Essential oil composition and antimicrobial activity of three zingiberaceae from S.Tome e Principe

The essential oil composition of three Zingiberaceae widely used as medicin al aromatic plants from S. Tome and Principe: Aframomum danielli (Hook. f.) K. Schum., Curcuma longa L. and Zingiber officinale Rosc. was studied. Two samples of the essential oils from fruit of A. danielli and from rhizomes of the other two species, were obtained by hydrodistillation and analyzed b y GC, GC-MS, and C-13-NMR. The essential oil from fruits of A. danielli has been studied for the first time and was characterised by its high content of monoterpenes, with 1,8-cineole (25.5-34.4%) the major constituent, follo wed by beta -pinene (14.1-15.2%) and alpha -terpineol (9.9-12.1%). Essentia l oils from the rhizomes of C longa contained a lower content of ar-turmero ne (4.0-12.8%) than those reported in the literature for C longa from other origins (24.7-31.4%), whereas the results for Z. officinale essential oils were in accordance with the literature data. The essential oils of A. dani elli and Z. officinale showed antimicrobial activity against all Gram-posit ive and Gram-negative bacteria tested, as well as against yeasts and filame ntous fungi, using the agar diffusion method.