Chemical Compositions of the Volatile Oils and Antibacterial Screening of Solvent Extract from Downy Lavender

Abstract

The discovery of a new species exhibiting more effective antibacterial properties is necessary because of the demand on Lavandula species, which continues to increase in a variety of industries. Lavandula pubescens might be a good alternative, as it exhibits strong antibacterial activity. In this study, the chemical composition of the essential oils from different organs (flowers, leaves, stems, and roots) of L. pubescens was identified using gas chromatography-mass spectrometry. Furthermore, the antimicrobial activities of different solvent extracts (methanol, ethanol, diethyl ether, hexane, and ethyl acetate) and different organ (flower, leaf, stem, and root) extracts of L. pubescens were evaluated. Only the ethyl acetate extracts of L. pubescens exhibited antibacterial activity against all bacterial strains tested, including Staphylococcus haemolyticus, Escherichia coli (KF 918342), Aeromonas hydrophila (KCTC 12487), E. coli (ATCC 35150), Cronobacter sakazakii (ATCC 29544), and Aeromonas salmonicida (KACC 15136). In particular, the extracts exhibited significant activity against S. haemolyticus. Ethyl acetate extract of the leaf exhibited the best activity against all bacterial strains. This study provides valuable information on the chemical compositions in essential oils and antimicrobial properties of L. pubescens.

Keywords: Lavandula pubescens; antibacterial activity; essential oil.

Figure 1

Photographs of the root (a), leaf and stem (b), and flower (c) of Lavandula pubescens.

Figure 2

Representative image showing antibacterial activity against a bacterial pathogen. Leaf (L), flower (F), root (R), and stem (S) of Lavandula pubescens.