A broad assessment of Eremurus spectabilis M. Bieb: chemical and elemental composition, total phenolic and antimicrobial activity analysis, and quantum chemical calculations of radical scavenging potential.

Eremurus spectabilis M. Bieb was extensively investigated experimentally and theoretically, including the antioxidant properties of compounds such as flavonoids, hydroxycinnamic acid derivatives, hydroxybenzoic acid derivatives, and organic acids. Antioxidant activity was investigated using the Density Functional Theory (DFT) method based on three known mechanisms: hydrogen atom transfer (HAT), single electron transfer followed by proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET). Subcritical water extraction (SWE), soxhlet extraction (SE), and solvent extraction (SOE) techniques were applied in the extraction process. Malic acid was the major compound with an extract concentration of 38,532.84 ± 1849.58 µg analyte/kg, total phenolics, and free radical scavenging activity were 10.67 mg gallic acid/mL extract and 73.89% per mg/mL extract, respectively. P, Fe, Na, Mg, K, and Ca were the main elements. The antibacterial activity of E. spectabilis against seven bacteria was evaluated, and it was found to be higher than the commercial antibiotics P10 and AMC30.