PHYSICOCHEMICAL PROPERTIES AND CHEMICAL COMPOSITION OF THE ESSENTIAL OIL OF AMOMUM XANTHIOIDES FROM A LUOI - THUA THIEN HUE

Abstract

Background: Amomum xanthiodes has been popularly used in traditional medicine. However, the knowledge about essential oil of A. xanthiodes from A Luoi district, Thua Thien Hue province (Viet Nam) is rather poor. In this study, we determined the physicochemical properties and chemical composition of seed essential oil of this species to provide scientific basis, clarify practical value, contribute to the development and conservation of precious medicine resources. Materials and method: Fruits of A. xanthiodes were collected from A Luoi - Thua Thien Hue in June 2017. The seed essential oil was extracted by using the hydrodistillation method. Its physicochemical properties were determined including density, refractive index, acid value, saponification value, ester value, and iod value. This oil was then analysed by gas chromatography/ mass spectrometry (GC/MS). Results: The yield obtained from the hydrodistillation procedures was 1.66% (v/w) calculated on a dry weight basis. Density (at 20oC) was 0.911, refractive index (at 20oC) was 1.4734, acid value was 12.74, saponification value was 110.97, ester value was 98,23, and iod value was 24.89. A total of 15 compounds were found in seed essential oil which belonged to monoterpenes and their derivatives. This oil comprised mainly of bornyl acetate (27.26%), camphor (23.73%), endo-borneol (13.78%), camphene (11.62%), D-limonene (10.96%), and β-myrcene (6.17%). Conclusion: the physicochemical properties and chemical composition of the essential oil of Amomum xanthioides from A Luoi – Thua Thien Hue have been determined. Key words: Amomum xanthiodes, essential oil, physicochemical properties, GC/MS, bornyl acetate, camphor