Characterization of Phenolic Profile and Biological Properties of Astragalus membranaceus Fisch. ex Bunge Commercial Samples

<i>Astragalus membranaceus</i> Fisch. ex Bunge (syn. <i>Astragalus mongholicus</i> Bunge) is one of the notable medicinal and food plants. Therefore, the aim of this study was to calculate the phenolic composition and antioxidant, antimicrobial, as well as enzyme inhibitory [acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase (TYR)] activities with chemometric approaches of the hydromethanolic and water extracts of commercial <i>A. membranaceus</i> samples. Ten individual phenolic compounds were determined using high-performance liquid chromatography (HPLC), and only quercetin was found at a level of above 80 µg/g DW in both extracts. Moreover, the highest antioxidant activity in DPPH, FRAP, ABTS, and CUPRAC assays was found in the sample containing the roots in loose form from USA. <i>A. membranaceus</i> extracts displayed the inhibition zone diameters within the range from 10 to 22 mm antimicrobial activity against <i>S. aureus</i>, while there were no inhibition zones in any extracts in case of <i>E. coli</i>. The extracts of <i>A. membranaceous</i> showed an inhibition rate below 40% against TYR, and among tested extracts, only two samples were able to inhibit BChE with IC₅₀ values of above 30 µg/mL. Correlation analysis showed a highly positive relationship between their phenolic composition and antioxidant activity. Concluding, the obtained results confirmed that <i>A. membranaceus</i> commercial samples could be an important dietary source of natural antioxidants.