Alpinia zerumbet is a medicinal plant from Asian origin used in folk medicine for the treatment of hypertension, which effect is attributed to terpinen-4-ol, the major component of the essential oil. The objective of this work was to identify the essential oil secretory structures in the leaf, flower, root and rhizome of this plant, and analyze the content and the chemical composition of the oil in the different organs of the plant. Sections were subjected to histochemical test with Nadi reagent for in situ localization of secretion. The essential oil extraction was performed by hydrodistillation in a Clevenger apparatus and the compounds were identified in CG-EM/FID. The histochemical test was positive for terpenoids, confirming the presence of essential oil stored in secretory structures named oils cells present in all analyzed organs. The higher essential oil content was found on the leaf (0.30%), while the petal and the rhizome presented content of 0.10% and 0.06%, respectively. It was not possible to determine essential oil content of the root due to the low amount of biomass produced. There were qualitative and quantitative differences in the chemical composition of the essential oil in the different plant organs, but the major constituent in all of them was the terpinen-4-ol, followed by 1,8 cineol in the leaf and by the α-terpineol in the flower and rhizome.
medicinal plant; terpinen-4-ol; secretory structure
