Unveiling the Multifunctional Bioactivity of Alpinia katsumadai Seed Essential Oil: GC – MS and HS ‐ SPME – GC – MS Chemical Profiling, Antimicrobial and Antioxidant Activities and Molecular Docking Insights

ABSTRACT This research investigated the chemical profiling, antimicrobial and antioxidant properties, and possible molecular mechanisms that explain the bioactivity of Alpinia katsumadai seed essential oil (EO). GC–MS and HS‐SPME–GC–MS analyses revealed 67 compounds, which accounted for 96.84% and 96.26% of the overall EO composition, respectively. The primary components included α‐guaiene (24.18%), p ‐but‐(1 E )‐enyl‐anisole (10.81%), Z ‐lanceol (7.27%), β‐phellandrene (6.84%), γ‐terpineol (4.09%), and geranyl propionate (3.81%). The EO demonstrated broad‐spectrum antimicrobial a against Gram‐positive bacteria ( Bacillus cereus , B. subtilis , and Micrococcus luteus ), Gram‐negative bacteria ( Escherichia coli and Helicobacter pylori ), and Candida albicans , with MIC values ranging from 1.80 to 2.00 mg/mL. DPPH and ABTS tests showed concentration‐dependent antioxidant activity with IC 50 values of 134.6 and 153.2 mg/L, respectively. Molecular docking offered mechanistic understanding of these functions by assessing key components against B. subtilis DNA gyrase B (4URM), H. pylori urease (1E9Y), and C. albicans CYP51 (5FSA). Significantly, Z ‐lanceol displayed the most advantageous and reliable interactions, possessing XP Gscores of −4.055, −5.387, and −8.303 kcal/mol, respectively. Its anticipated affinities for urease and CYP51 surpassed those of acetohydroxamic acid and fluconazole. Together, these results highlight A. katsumadai seed EO, especially Z ‐lanceol, as a valuable source of multifunctional bioactive substances with possible uses in food preservation, pharmaceuticals, and cosmetics.