Baby Sabulal, Rajani Kurup, Varughese George*, Mathew Dan and Nediyaparambu Sukumaran Pradeep

Abstract: Essential oils from the rhizomes and leaves of Amomum hypoleucum were hydrodistilled and characterized by GC/FID and GC/MS. Nineteen constituents comprising 93.0% were identified from the rhizome oil. Cryptone (15.4%), β-pinene (11.9%) and caryophyllene oxide (7.6%) were the major constituents in the rhizome oil. Fifty-two constituents comprising 97.6% were identified from the leaf oil. (E)-Nerolidol (26.5%), α-fenchyl acetate (15.0%) and β-caryophyllene (8.4%) were the major constituents in the leaf oil. These oils showed good antibacterial activity against the Gram-negative bacteria, Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli.

The genus Amomum in Zingiberaceae family has sixteen species in India and of these, six are distributed in South India (1). We have recently reported the chemical compositions and antimicrobial activities of the oils from Amomum cannicarpum, A. muricatum and A. pterocarpum from the Western Ghats region in South India (2–4). β-Pinene has been the major constituent in these oils and most of the other previously reported Amomum oils (2–4). But, 1,8-cineole has been the major component in the seed oil of A. subulatum (5–6). Amomum hypoleucum is a rare species distributed in the hilly regions of Peninsular India and Sri Lanka. In this study, we report the chemical composition and antibacterial activity of the rhizome and leaf oils of A. hypoleucum.