Bioassay-guided isolation of the antimicrobial compounds of Coleus amboinicus Loureiro (Lamiaceae)
Author(s): E. A. Vasquez1, W. Krause2, J. Conrad2, B. Volger2, C. Zebitz3 and B. M. Rejesue3
Abstract
The essential oil of the aerial part of Coleus amboinicus showed antibacterial activity against Bacillus subtilis (gram +) and Pseudomonas fluorescens (gram -) and antifungal activity against Cladosporium cucumerinum. Bioassay-guided fractionation revealed that carvacrol and ß-caryophyllene-4,5-oxide were the major contributors to the antimicrobial activity of the essential oil. The sesquiterpene α-humulene and monoterpenes α-pinene, α-terpmene and cymene present in significant amounts were inactive.
Keywords : Coleus amboinicus, essential oil, antibacterial, antifungal, carvacrol, caryophyllene-4,5-oxide