Comparative Phytochemical Profiling and α-Glucosidase Inhibitory Potential of Acca sellowiana (O.Berg) Burret Plant Parts: Antioxidant Activity Supported by LC–MS/MS and Molecular Docking

Comparative data on different parts of Acca sellowiana and their enzyme-inhibitory mechanisms remain limited. This study evaluated flower, fruit, leaf, and branch extracts using bioactivity-guided LC–MS/MS and molecular docking to clarify their antioxidant and antidiabetic potential. Total phenolic, flavonoid, and tannin contents were measured, antioxidant activity was assessed by DPPH and ABTS assays, and inhibition of α-glucosidase, α-amylase, AChE, BChE was determined. The most active extract was analyzed by validated LC–MS/MS, major compounds were docked with target enzymes. Leaf extract showed the highest phenolics (89.12 µg GAE/mg), flavonoids (1010.67 µg RE/mg), and tannins (152.44 µg TAE/mg). Branch and leaf exhibited strongest antioxidants (DPPH 61.8%/55.5%; ABTS 51.1%/57.2%), surpassing α-tocopherol. Branch extract showed the most potent α-glucosidase inhibition (IC50 107.9 µg/mL vs. acarbose 3081.8 µg/mL). LC–MS/MS revealed high quercetin, epigallocatechin gallate, ellagic, and gallic acids. Results highlight organ-dependent activity and identify plant as a source of natural α-glucosidase inhibitors.