Composition and antimicrobial activity of essential oils of two populations of Tanzanian Lippia javanica (Burm. f.) Spreng. (Verbenaceae)

The chemical composition of essential oils obtained from leaves of two samples of Lippia javanica (Burm. f.) Spreng, collected from the same locality in Tanzania, was analysed by GC and GC–MS. Sixty constituents (91.3%) of one sample and 38 constituents (76.0%) of the other sample were identified. The main components of the two oils were geranial, neral, limonene, germacrene‐D, camphor, linalool, β‐caryophyllene and myrcene. The two oils were significantly different in their chemical composition. This implies that the two L. javanica populations could be two different chemical races. Furthermore, antimicrobial activity of the oils was evaluated against six Gram‐positive or Gram‐negative bacteria and three pathogenic fungi, using the agar dilution technique. It was found that both oils exhibited moderate to strong activities against the bacteria tested, while both were inactive against the fungi tested. Copyright © 2003 John Wiley & Sons, Ltd.