Abstract
The chemical composition of the essential oils from the rhizomes of four South Indian Hedychium species, viz. H. venustum Wight, H. spicatum Ham. ex Smith var. acuminatum (Roscoe) Wall., H. coronarium Koenig and H.flavescens Carey ex Roscoe was investigated by GC and GC/MS. 1,8-Cineole was the most abundant constituent in the first three oils, present at concentrations of 45.4%, 44.3% and 48.7%, respectively. β-Pinene (43.6%) was the major constituent in the oil from H. flavescens. The percentages of sesquiterpenes were the highest in the rhizome oil of H. venustum (24.0%) followed by H. spicatum var. acuminatum (22.2%), H. flavescens (0.6%) and H. coronarium (0.5%). The antimicrobial activities of all four rhizome oils were tested by the disc diffusion method against three Gram-positive and seven Gram-negative bacteria and two fungi. The strongest activities were observed for the rhizome oil from H. flavescens, especially against Salmonella typhi (23 mm inhibition zone), Escherichia coli (18 mm), Proteus vulgaris (15 mm) and the fungi Candida albicans (13 mm) and C. glabrata (14 mm).