Chemotaxonomic Studies on the Genus Amomum Based on Chemical Components of Volatile Oils

Abstract

The study was focused on six species of Amomum genus i.e. A. aculeatum Roxb., A. blumeanum Val., A. compactum Soland. ex Maton., A. longipes Val., A. roseum Benth. et Hook.f., A. truncatum Gagn., and one species of Elettaria cardamomum Maton. The aims of the study were to find out percentage of volatile oil and the number of chemical components in the volatile oil in the rhizome of plants. In addition, I also determined percentage of volatile oil, the number of chemical components of volatile oil in the rhizome of A. compactum (Javanese cardamom); and the phylogenetic relationship of species belonging to genus Amomum based on the similarity index of the number of chemical components in the volatile oil. The volatile oil contents in the seven species of rhizome varies from 0.25-2.25% (v/w), and in the seven organs of A. compactum from 1.0- 3.5%. The total number of volatile oil components of the rhizome (content >1%) was 61 compounds and in several organs of A. compactum was 45 compounds. The rhizome showed 10 major components at the RT value of 7.43, 9.04, 11.07, 11.39, 13.57, 14.91, 17.41, 18.30, 18.46, and 18.72. The seven organs of A. compactum had seven major components at RT value of 7.34, 7.42, 7.56, 11.08, 13.58, 16.12, and 18.28. The relationships of those seven species were as follows: A. blumeanum and A. longipes had close relationship on the similarity index of 80%, A. aculeatum 75%, and A. truncatum 70%. This group joined with A. roseum, A. compactum and E. cardamomum at the similarity index of 67%. The phylogenetic dendrogram showed that all species had similarity index at least 67%, suggested that taxonomic status of the genus Elettaria need to be observed in details. The similarity index of seven organs of A. compactum were at least 60%.