Essential Oils Profiling of four desert plants naturally grown in Galala plateau, Northeastern desert, Egypt

Desert ecosystems harbor unique plant species with adaptive metabolic pathways, yet their phytochemical diversity remains underexplored. Essential oils derived from such plants are of particular interest for their potential pharmaceutical, cosmetic, and industrial applications. Aerial parts of the plants were collected, shade-dried, and subjected to hexane cold maceration for essential oil extraction. The obtained oils were analyzed using Gas Chromatography–Mass Spectrometry (GC-MS). Compound identification was based on retention indices and spectral comparisons with NIST and Wiley libraries. Over 70 volatile compounds were identified across the four species, including terpenes, aldehydes, amines, retinoids, long-chain alcohols, imidazole derivatives, and sugar-like osmolytes. L. coronopifolia oils were rich in thymol analogs and sesquiterpenes (β-bisabolene, caryophyllene), while P. crispa exhibited nitrogen-rich amines and neuroactive constituents such as octodrine. I. mucronata showed the rare occurrence of retinol (vitamin A) and long-chain alcohols, while S. aegyptiaca displayed aldehyde-rich and sugar-derivative profiles. Common stress-associated metabolites, including pterin-6-carboxylic acid and imidazole derivatives, were detected in all four species, suggesting convergent adaptation to desert stress. The essential oils of these Galala Plateau species revealed remarkable chemical diversity, with distinctive compounds serving as potential chemotaxonomic markers. Their profiles highlight significant prospects for pharmaceutical, cosmetic, nutraceutical, and agricultural applications. These findings enhance the phytochemical database of North African desert flora and support the sustainable valorization of underutilized plant resources.