Chemical Composition and Antibacterial Activity of Lippia multiflora Moldenke Essential Oil from Different Regions of Angola

Abstract

The purpose of the study was to determine the chemical composition and antibacterialactivity ofLippia multifloraMoldenke essential oils (EOs) collected in different regions of Angola.Antibacterial activity was evaluated using the agar wells technique and vapour phase test. Analysisof the oils by GC/MS identified thirty-five components representing 67.5 to 100% of the totaloils. Monoterpene hydrocarbons were the most prevalent compounds, followed by oxygenatedmonoterpenes. The content of the compounds varied according to the samples. The main componentswere Limonene, Piperitenone, Neral, Citral, Elemol, p-cymene, Transtagetone, and Artemisia ketone.Only one of the eleven samples contained Verbenone as the majority compound. In the vapour phasetest, a single oil was the most effective against all the pathogens studied. The principal componentanalysis (PCA) and hierarchical cluster analysis (HCA) of components of the selected EOs andinhibition zone diameter values of agar wells technique allowed us to identify a variability betweenthe plants from the two provinces, but also intraspecific variability between sub-groups within apopulation. Each group of essential oils constituted a chemotype responsible for their bacterialinhibition capacity. The results presented here suggest that AngolanLippia multifloraMoldenke hasantibacterial properties and could be a potential source of antimicrobial agents for the pharmaceuticaland food industry