Morphological Features and Biological Activity of Different Extracts of <i>Echinops spinosissimus</i> Grown in Saudi Arabia

Based on a shortage of available data on <i>Echinops spinosissimus</i> in Saudi Arabia, the current study’s aim was to present some new information on the topic. Plant samples were collected from different locations in the northeast of Mecca. Out of fifteen species from this genus found in Saudi Arabia, one species was targeted in the current study. It was noted as a perennial subshrub that is 30–80 cm in length. Its stem is gray, striate, and slightly covered with glandular hairs. The epidermis is converted into cork cells in older stem parts. The vascular system showed a continuous siphonostelic structure and dissected vascular bundles. The lamina is abaxially rounded and straight. The pollen grains are monads, radially symmetric, medium-sized, and a prolate spheroidal shape with an aculeate–foveolate exine structure. Based on its historical pharmaceutical properties, the phytochemical properties were studied, and it was noted that ethyl acetate was the best solvent for producing high amounts of bioactive compounds such as phenols, flavonoids, and alkaloids. The obtained extracts appeared to exhibit high activity against Gram-positive pathogenic bacteria. These extracts were identified by using HPLC and GC-MS. Many bioactive compounds were detected, such as protocatechuic acid, gallic acid, rutin, vanillic acid, quercetin, and kaempferol. Additionally, four main compounds, including hexadecanoic, stearic, oleic, and linoleic acids, were detected via GC-MS. The total antioxidants of <i>E. spinosissimus</i> extracts showed that the ethyl acetate extract exhibited a high total antioxidant capacity and free radical-scavenging properties.