Enhanced Energized Dispersive–Guided Extraction Using Doehlert Matrix Optimization and Antioxidant Evaluation of Phenolic Compounds From Herbal Leaves by Using High-Performance Liquid Chromatography

Secondary metabolites are important bioactive compounds for diet and medicine. This study optimizes the extraction of hydroethanolic herbal extracts using an EDGE (Energized Dispersive Guided Extraction) system, evaluates their antioxidant capacity, and analyzes correlations among antioxidant activity, total phenolic content, and individual compounds. A Doehlert matrix design was used to optimize extraction, having temperature and time as independent variables, and total phenolic content (mg GAE/g) as the response, quantified via the Folin–Ciocalteu method. Response surface methodology and analysis of variance validated the model. Extracts were characterized by high-performance liquid chromatography with diode array detector, and antioxidant capacity was assessed using three different assays. Correlation analysis explored potential synergistic effects. Optimal extraction conditions (40% ethanol, 60% water, 165.82°C, 6.03 min) yielded a significant model (p < 0.05, R² = 0.99). The mean total phenolic content was 69.18 mg GAE/g (SD = 0.73%). Chromatographic analysis confirmed phenolic acids, highlighting rutin in Crataegus oxyacantha and theophylline in Sorocea bonplandii. Antioxidant assays indicated a strong presence of active compounds, and correlation analysis suggested synergistic effects among constituents. The optimized extraction method effectively enhanced phenolic compound yield and antioxidant properties. The findings highlight potential synergistic interactions among phenolic constituents, contributing to the functional properties of the herbal extracts.