Chemical Composition and Antibacterial Properties of Essential Oil Extracted from the Leaves and the Rhizomes of Stahlianthus thorelii Gagnep. (Zingiberaceae)

Stahlianthus thorelii Gagnep. is a plant belonging to the family Zingiberaceae, widely distributed in Asian countries like China, Thailand, India and Vietnam. In traditional oriental medicine, this plant is usually used to treat hemorrhage, heavy menstruation, poor digestion, rheumatism and bone / joint pain (tuberous roots). For the first time, the essential oils from the leaves and the rhizomes of S. thorelii collected in Vietnam were analyzed by Gas Chromatography-coupled with Mass Spectrometry (GC/MS) and investigated for their in vitro anti-microbacterial activity against several Gram (+) / (-) bacteria, fungi and yeast. A total of twenty and thirty components were detected accounting for 81.5 % and 95.5 % of the rhizome and leaf oils, respectively. These volatile compounds were identified as a complex of monoterpene fractions (14.2 % / 9.4 %) and mainly sesquiterpenes (60.0 % / 63.9 %) respectively. The most abundant sesquiterpenes in rhizome were found to be α-copaene (32.2 %) and (-)-allo-aromadendrene (11.3 %) while these compounds in leaves were identified only as 5.0 % and 5.3 %, respectively. In the antibacterial tests, the rhizome oil at MIC 150-200 μg/ml exhibited distinct activity against the Gram (+) bacteria Bacillus subtilis, Staphylococcus aureus, and the fungi Aspergillus niger. While the oil obtained from leaves at MIC 200 μg/ml showed inhibitory activity against B. subtillis.