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.

摘要

Elettaria cardamomum (L.) Maton (Zingiberaceae)，俗称绿色或真豆蔻，是一种重要的商业物种，其种子广泛用于制药、化妆品和食品工业。尽管国际市场对豆蔻精油的需求不断增加，但对不同植物部位挥发性化合物的化学分析还没有得到很好的探索。虽然其他植物地理区域对其叶油的化学特性进行了一些研究，但尚未报道茎中精油的存在和化学成分。因此，本研究旨在表征小豆蔻叶和茎精油的化学成分和抗氧化活性。通过水蒸馏从叶和茎中提取的精油显示存在 43 和 37 种化合物，通过 GC/MS 分析分别占总油的 92.71% 和 92.12%。叶精油的主要成分是1,8-桉树脑（20.66%）、莰烯（18.09%）、樟脑（10.02%）和三环烯（7.36%）；而 α-松油醇乙酸酯 (19.75%)、1,8-桉树脑 (10.38%)、石竹烯氧化物 (7.13%) 和 β-eudesmol (4.85%) 富含茎精油。氧化单萜是小豆蔻叶和茎精油中的主要萜类成分. 通过 DPPH (2, 2-diphenyl-1-picrylhydrazyl) 和 ABTS (2, 2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) 试验评估的自由基清除能力表明，与茎油相比，叶油具有更好的活性. 目前的研究结果表明，在印度东部野生的小豆蔻可被视为一种重要的生物资源和天然抗氧化剂。