Phenolic Profiling and Bioactivity Evaluation of Stachys aleurites Extracts: LC-ESI-MS/MS Characterization,...

Natural products rich in phenolic compounds are increasingly investigated as multifunctional agents against oxidative stress and enzyme-related disorders. This study characterized the phytochemical composition and evaluated the antioxidant and enzyme inhibitory activities of methanol and aqueous extracts of Stachys aleurites. Total phenolic and flavonoid contents were determined spectrophotometrically, while selected phenolics were quantified by LC-ESI-MS/MS. Antioxidant and enzyme inhibitory properties were assessed using complementary in vitro assays. The methanol extract contained higher levels of total phenolics (48.86 mg GAE/g) and flavonoids (65.36 mg RE/g) than the aqueous extract. Verbascoside and chlorogenic acid were the predominant compounds in the methanol extract, whereas p-coumaric acid was relatively more abundant in the aqueous extract. The methanol extract exhibited stronger antioxidant activity in most assays and showed greater inhibition of AChE, tyrosinase, α-amylase, and α-glucosidase. In contrast, the aqueous extract displayed slightly higher metal-chelating activity and stronger BChE inhibition. These findings demonstrate solvent-dependent variations in phytochemical composition and bioactivity, highlighting the importance of extraction solvent selection and supporting further studies on the bioactive constituents of S. aleurites.