By Baby Sabulal, Varughese George and Mathew Dan

Abstract: Abstract: Essential oils obtained by hydrodistillation from the rhizomes and leaves of Amomum pterocarpum (Zingiberaceae) were analyzed by GC/FID and GC/MS. Thirty-six constituents each were identified from the rhizome (95.7%) and leaf oils (92.6%). β-Pinene was the major constituent in both the rhizome oil (65.5%) and the leaf oil (41.7%). Phytol (26.5%) was the other major constituent in the leaf oil. Key Word Index: Amomum pterocarpum, Zingiberaceae, essential oil composition, β-pinene, phytol.

Introduction
The genus Amomum has about 90 species and is mostly distributed in Africa, tropical Asia, Australia and the Pacific Islands. Of the 16 Amomum species in India, six are reported from South India (1,2). Plants in this genus are mostly terrestrial, rhizomatous herbs (2). Amomum species of plants are used as spices and in traditional medicine for curing toothache, dysentery, diarrhoea, rheumatism, vomiting, dyspepsia, lung diseases, etc. (3). Amomum subulatum or ‘large cardamom’ distributed in eastern Himalayas is the most investigated Amomum species. The chemical composition of the essential oils from fresh and dry seeds of different strains of A. subulatum have been studied by various groups and the major constituent, 1,8-cineole, has been found to vary from 61.3–86% (4–7). Also, oils of different parts of other Amomum species such as A. thyrsoideum (8), A. longiligulare (8), A. villosum (9), A. muricarpum (10), A. kwangsiense (11), A. schmidtti (12), A. xanthioides (13), A. tsao-ko (13), A. linguiforme (3,14) and A. testaceum (15) have been previously studied. We recently reported the chemical composition of leaf oils of two endemic south Indian Amomum species: A. cannicarpum and A. muricatum (16,17). β-Pinene was the major constituent in most of the oils from the rhizomes and leaves of Amomum species studied (8–17).

Amomum pterocarpum is a rare endemic species distributed in hilly regions of moist evergreen forests in South India and has not been previously investigated. Hence, we report the chemical composition of oils from the rhizomes and leaves of A. pterocarpum.