Chemical Composition and Antioxidant Activities of Essential oil from Leaf and Stem of Elettaria cardamomum from Eastern India

Abstract

Elettaria cardamomum (L.) Maton (Zingiberaceae), commonly known as green or true cardamom, is a commercially important species, the seeds of which are extensively used in the pharmaceutical, cosmetic and food industries. In spite of the increasing demand for cardamom essential oil in the international market, the chemical profiling of volatile compounds of different plant parts are not well explored. Though there are a few studies on the chemical characteristics of its leaf oil from other phytogeographical regions, the presence and chemical composition of essential oil from stems have not yet been reported. Therefore, the present study was undertaken to characterize the chemical composition and antioxidant activity of leaf and stem essential oil of E. cardamomum. The essential oil extracted by hydro-distillation from the leaf and stem revealed the presence of 43 and 37 compounds, representing 92.71 % and 92.12 % of total oil respectively by GC/MS analysis. The major constituents of the leaf essential oil were 1,8-cineole (20.66 %), camphene (18.09 %), camphor (10.02 %) and tricyclene (7.36 %); whereas α-terpinyl acetate (19.75 %), 1,8-cineole (10.38 %), caryophyllene oxide (7.13 %) and β-eudesmol (4.85 %) were rich in the stem essential oil. Oxygenated monoterpenes were the major terpenic fraction in the leaf and stem essential oil of E. cardamomum. The free radical scavenging ability assessed by DPPH (2, 2-diphenyl-1-picrylhydrazyl) and ABTS (2, 2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) assay showed that leaf oil had better activities as compared to stem oil. The present findings demonstrated that E. cardamomum growing wild in Eastern India could be considered as an important bioresource and natural antioxidant.