Essential Oils from Seeds and Pods of Aframomum corrorima and Rhizomes of Zingiber officinale from Ethiopia

Zingiberaceae essential oil (EO) from seeds and pods of Aframomum corrorima (Braun) Jansen and rhizomes of Zingiber officinale Roscoe were obtained by steam distillation and analyzed by gas chromatography (GC) and gas chromatographymass spectrometry (GCMS). Over 60 compounds could be detected and identified in the pod oil of A. corrorima, in contrast to the less complex seed oil (>40 compounds). The seeds, which are widely applied in herbal medicine, contained mainly monoterpenes such as 1,8-cineole (44.3 %), sabinene (17.3 %), beta-pinene (7.2 %) and alpha-terpinyl acetate (6.0 %). Despite the many monoterpenes in the pod EO with gamma-terpinene as the main compound (4.9 %), this oil was dominated by sesquiterpenic structures such as E-nerolidol (17.2 %), beta-caryophyllene (9.7 %) and its oxide (6.9 %), cyperene (6.4 %) and eudes-7(11)-en-4-ol (5.9 %). The EO yield was 3.8 and 0.27 % (v/w) for seeds and pods, respectively. More than 50 compounds were detected and identified in the rhizome EO of Ethiopian Zingiber officinale. The main EO constituents were the characteristic alpha-curcumene (17.4 %) and relative high amounts of alpha-zingiberene (14.2 %), beta-sesquiphellandrene (12.0 %) and beta-bisabolene (8.3 %). The EO of Z. officinale rhizomes was observed to be rich in sesquiterpenic structures, whereas the total amount of monoterpenes comprised only 9 %.