Chemical Composition and Antimicrobial Activity of Aerial Parts Essential Oils from Three Turkish Heracleum Species

Abstract The genus Heracleum (Apiaceae) comprises aromatic plants traditionally used in folk medicine for various ailments, particularly digestive complaints. This study aimed to characterize the chemical composition and antimicrobial potential of essential oils obtained from the aerial parts of H. argaeum, H. platytaenium , and H. sphondylium subsp. ternatum , supported by multivariate analysis and in silico investigations. Essential oils were analysed using GC-FID/GC-MS, and their antimicrobial activities were evaluated experimentally. Multivariate analysis, molecular docking against fungal CYP51, and ADMET predictions were performed to investigate chemical variability and the pharmacological potential of selected constituents. Essential oil yields ranged from 0.07 to 0.18% (v/w), with identified constituents representing 95.1–98.8% of the oils. H. argaeum exhibited a mixed monoterpene-ester profile, whereas H. platytaenium and H. sphondylium subsp. ternatum were dominated by hexyl butyrate and octyl acetate, respectively. The first detailed relative-percentage compositional profile of H. argaeum aerial-part oil was established. All oils showed their strongest antimicrobial activity against Candida krusei , with H. argaeum exhibiting the lowest MIC (1.25 mg/mL). (-) -Limonene demonstrated the most favorable predicted CYP51 binding affinities, mainly through hydrophobic interactions. ADMET predictions indicated high intestinal absorption and no AMES, hepatotoxicity, or hERG alerts, although four constituents showed skin-sensitisation alerts. These findings expand knowledge of the chemical diversity of Heracleum essential oils and provide a basis for further experimental investigation of their antifungal potential.