As part of ongoing research on the chemical composition and the antimicrobial properties of Burkinabe
plants essential oils alone and in combination, essential oils (EOs) from leaves of Cymbopogon citratus and
Cymbopogon giganteus from Burkina Faso were analyzed by GC–FID and GC–MS. Five constituents, which
accounted for 96.3% of the oil, were identified in the EO of C. citratus. Geranial (48.1%), neral (34.6%) and
myrcene (11.0%) were the major constituents. For C. giganteus a total of eight compounds were identified
which represented 86.0% of the oils extracted. The dominant compounds were limonene (42%) and a set of
monoterpene alcohols: trans-p-mentha-1(7),8-dien-2-ol (14.2%), cis-p-mentha-1(7),8-dien-2-ol (12%),
trans-p-mentha-2,8-dien-1-ol (5.6%) and cis-p-mentha-2,8-dien-1-ol (5.2%). The EOs were tested against
nine bacteria by using disc diffusion and microdilution methods. C. giganteus EO showed antimicrobial
effects against all microorganisms tested whereas C. citratus EO failed to inhibit Pseudomonas aeruginosa.
The antimicrobial activity of combinations of the two EOs was quantified by the checkerboard method.
Combinations of the two EOs exerted synergistic, additive and indifferent antimicrobial effects. Results
of the present investigation provide evidence that the combinations of plant EOs could be assessed for
synergistic activity in order to reduce their minimum effective dose.

Cymbopogon citratus Cymbopogon giganteus Essential oils Chemical composition Antimicrobial Combination