GC–MS Characterization and In Vitro Antibacterial Activity of Pelargonium graveolens L’Hér. Essential Oil from Tajoura, Libya

Abstract

ABSTRACT

Background: Pelargonium graveolens L’Hér. essential oil is valued for its chemical constituents and antimicrobial potential. To our knowledge, no previous study has combined GC–MS characterization with antibacterial screening of Libyan-cultivated P. graveolens.

Aims: This study investigated its chemical composition, antibacterial activity, and relationship to ISO 4731:2012 and published North African profiles.

Methods: Essential oil was extracted from fresh aerial parts collected in Tajoura, Libya, by Clevenger hydrodistillation. Chemical composition was analyzed using GC–MS, while antibacterial activity was evaluated against five reference bacterial strains using disc diffusion (4 µL/disc).

Results: The oil yield was 0.8% (v/w). GC–MS recorded 52 peaks, dominated by citronellol (26.74%), citronellyl formate (11.79%), isomenthone (10.50%), geraniol (8.97%), and linalool (5.44%). Partial numerical agreement with ISO 4731:2012 was observed. The strongest antibacterial activity was recorded against Staphylococcus aureus (21.00 ± 1.00 mm) and Staphylococcus epidermidis (20.00 ± 1.00 mm).

Conclusion: Libyan P. graveolens essential oil exhibited a citronellol-dominant profile and measurable antibacterial activity. These findings provide preliminary evidence supporting further quality assessment and quantitative antimicrobial investigations.