Solvent-dependent variation in phenolic profiles, antioxidant and antibacterial activities across wild populations of Allium jesdianum

Allium jesdianum, an endangered medicinal plant endemic to Iran, exhibits notable pharmacological properties, including antioxidant and antibacterial effects. This study explored the influence of solvent polarity on the extraction efficiency of phytochemicals and their associated bioactivities in wild populations of A. jesdianum collected from six natural habitats (P1–P6). Aerial parts of the plant were extracted using methanol, followed by fractionation with ethyl acetate and n-hexane. Total phenolic and flavonoid contents were quantified via Folin–Ciocalteu and aluminum chloride methods. Antioxidant activity was assessed using DPPH and FRAP assays, while antibacterial potential was evaluated against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa using MIC and MBC assays. Despite its acknowledged medicinal significance, the variation in phytochemical composition and bioactivities of A. jesdianum at the population level has been largely overlooked. To fill this gap in knowledge, the current study offers the inaugural systematic and comparative assessment of various wild populations from six different natural environments, incorporating the influences of population origin and solvent polarity on the bioactive potential of the plant. The results showed that both solvent type and population origin significantly influenced phytochemical content and biological activity. Ethyl acetate and n-hexane fractions from the P5 and P6 populations yielded the highest levels of phenolics (70.37 mg GAE g−1) and flavonoids (234.75 mg Rutin g−1), along with the strongest antioxidant and antibacterial effects (IC₅₀ = 0.034 mg mL−1; MIC = 2 mg mL−1 against S. aureus). HPLC analysis identified ferulic acid and rutin as predominant bioactive compounds, whose accumulation correlated strongly with soil macronutrients (N, P, K), rather than altitude. Heat map and PCA analyses revealed pronounced phytochemical diversity among the wild populations, with P6 showing superior metabolite profiles. The high bioactive properties of populations P5 and P6 suggest their suitability for targeted conservation, selective cultivation, and use in pharmaceutical or nutraceutical products, offering valuable advice for population-specific approaches to preserve and capitalise on the medicinal value of A. jesdianum.