Abstract

This research aimed to optimize solvent concentration and extraction conditions for total phenolic content (TPC) and antioxidantactivity (DPPH and ABTS) in VT leaves using ultrasound-assisted extraction (UAE). A simplex-lattice design incorporating anaqueous–polyol mixture and a central composite design (CCD) within response surface methodology (RSM) were utilized. Theoptimal solvent composition was determined to be 37.32% w/v aqueous, 26.87% w/v glycerin, and 35.81% w/v butylene glycol, withan ideal solvent-to-sample ratio of 33.21:1 mL/g and an extraction duration of 15 min. UAE with the aqueous–butylene glyco-l–glycerin (U-BG) mixture signifcantly enhanced TPC and antioxidant activity compared to conventional maceration methods(p < 0.05). Key bioactive compounds identifed included Orientalol E, (+)-15-Beyeren-3-one, and petunidin-3-O-arabinoside. TheU-BG extract exhibited higher cell viability and antioxidant activity compared with ethanol-based extracts and demonstratedstrong wound-healing properties, achieving efective wound closure within 20 h. This study underscores the potential ofaqueous–polyol extraction for enhancing bioactive compound recovery, ofering sustainable solutions for the cosmetic andpharmaceutical industries.