Chemical Composition of Essential Oils of Different Hypericum Species Growing Wild in Shouf Biosphere Reserve, Lebanon

Abstract

This study aims to assess the chemical composition of six Hypericum species growing wild in Shouf Biosphere Reserve (SBR) of Lebanon and discuss therapeutic potential of their different constituents. Fresh aerial parts were randomly collected from different locations during the flowering stage of the plant in 2022. Using hydrodistillation by Clevenger apparatus, essential oils were isolated and then analysed by gas chromatography (GC) and GCMass spectrometry. A total of 134 different chemical compounds were identified. H. triquetrifolium illustrated the highest diversity of compounds (55) followed by H. lanuginosum (51), H. perforatum (38) and H. thymifolium (30), H. libanoticum (23) and H. hircinum (15). While hydrogenated sesquiterpenes constituted the highest percentages of the overall composition of H. triquetrifolium, H. hircinum and H. perforatum (45.08 %), 31.88 % and 67.97%, respectively, oxygenated monoterpenes and hydrogenated monoterpenes were dominant in H. lanuginosum and H. thymifolium, respectively. Major compounds included β-Caryophyllene, γ-Terpinen, Ylangene, and α-Elemene found in the literature to have a wide range of therapeutic effects in pharmacological research. Findings confirm the traditional use of studied Hypericum species and the high potential of essential oils as rich source of many bioactive compounds of wide applications in pharmaceutical, cosmetics and food industries.