Leopold Jirovetz,* Gerhard Buchbauer and Gernot Eller, Martin Benoit Ngassoum, Pierre M. Maponmetsem

Abstract: The essential oils of fresh flowers (2 samples), leaves and stems of Cymbopogon giganteus (Hochst.) Chiovenda from Cameroon were investigated by GC and GC/MS. More than 55 components have been identified in the samples 1 (flowers 1), 2 (leaves), 3 (stems) and 4 (flowers 2) with main compounds possessing the p-menthadiene skeleton as follows: cis-p-mentha-1(7),8-dien-2-ol (1: 22.8%, 2: 27.7%, 3: 29.1%, 4: 20.5%), trans-p-mentha-1(7),8-dien-2-ol (1: 24.9%, 2: 21.6%, 3: 28.1%, 4: 26.5%), trans-p-mentha-2,8-dien-1-ol (1: 17.3%, 2: 22.1%, 3: 21.4%, 4: 16.3%) and cis-p-mentha-2,8-dien-1-ol (1: 8.3%, 2: 5.4%, 3: 4.6%, 4: 9.7%). Additional components in higher concentrations, responsible for the characteristic aroma impressions of these samples are especially limonene, trans-verbenol and carvone as well as some other mono- and sesquiterpenes. Antimicrobial activities of the four oils were found against Gram-(+)- and Gram-(-)-bacteria as well as the yeast Candida albicans, and these results were discussed with the compositions of each sample.

Fresh plants of C. giganteus were collected at the Waza-Park near Mora-City, North-Province, Cameroon, during February 2005 (dry season, morning-time). The plants were identified by botanists of the University of Yaounde (Cameroon) and a voucher specimen (no. 13971 SFRCAM) has been deposited in the specially maintained Herbarium of Yaounde.