Compositional and comparative analysis of two Omani Helichrysum somalense Baker f. essential oils

In the present study, the chemical compositions of essential oils (EOs) of two Omani accessions of Helichrysum somalense Baker f. (Asteraceae) (Hs1 and Hs2), a species completely unexplored, were evaluated by GC-MS. Both samples were predominantly composed of sesquiterpene compounds (62.62% and 80.68%, respectively). Ledol (16.51%), α-muurolene (6.57%), and δ-cadinene (6.53%) were the main components of Hs1; the latter two compounds of Hs1 also represented the main metabolites identified in Hs2 (16.54% and 11.88%, respectively). Furthermore, both oils showed significant quantities of the monoterpene hydrocarbon α-pinene (5.87–9.26%). In parallel, complete literature reviews were conducted regarding the composition of the essential oils, as well as the ethnobotanical utilisation, of all the other Helichrysum taxa co-occurring in the Arabian Peninsula.