Abstract
The Egyptian Sinai is a rich source of plant-derived medicines from the highly represented Asteraceae family; however, the protocol for effective chemical extraction has not been standardized. To identify an effective extraction method for essential oils for highly represented species, Achillea fragrantissima, Artemisia judaica and Tanacetum sinaicum were analysed by hydro-distillation (HD) vs microwave-assisted (MA) extraction. A total of 82 metabolites were identified by gas chromatography-mass spectrometry (GC-MS). While oxygenated monoterpenes were the major class for both methods, MA extraction proved to be slightly more effective in extracting some ketones and alcohols such as piperitone and thymol, respectively. All the extracted EOs from the three plants exhibited significant antimicrobial potentialities in which T sinaicum > A judaica > A fragrantissima. Interestingly, essential oils extracted by HD (vs MAE) exhibited greater lettuce phytotoxicity with respect to root and shoot growth as well as seed germination. Although the two extraction methods produce slightly different chemical profiles for the three analysed species, the plants aggregated similarly based on principal component analysis.