Ultrasound-Assisted Extraction Processes of Benzopyrans from Hypericum polyanthemum: COSMO-RS Prediction and Mass Transfer Modeling

Abstract

Efficient and sustainable extraction of bioactive benzopyrans from Hypericum polyanthemum Klotzsch ex Reichardt (Hypericaceae) remains underexplored, despite their potential applications. The current study aimed to optimize this process by integrating computational simulation and experimental extraction with suitable solvents. The COSMO-RS model was employed to screen deep eutectic solvents (DESs), indicating lactic acid/glycine/water 3:1:3 (DES 1) as a highly promising candidate based on activity coefficients at infinite dilution for target benzopyrans (HP1, HP2, HP3). Ultrasound-assisted extraction (UAE) was then conducted using the proposed DES as well as hexane, and the extracts were analyzed via high-performance liquid chromatography (HPLC) and spectrophotometry for total phenolic content (TPC). The results for DES 1 showed yields for benzopyrans HP1 (1.43 ± 0.09 mg/g plant) and HP2 (0.55 ± 0.04 mg/g plant) close to those obtained in the hexane extract (1.65 and 0.78 mg/g plant, respectively), corroborating the use of COSMO-RS for solvent screening. Kinetic analysis using an adapted Crank diffusion model successfully described the mass transfer process for DES 1 (R2 > 0.98, mean average percent error < 9%), indicating diffusion control and allowing estimation of effective diffusion coefficients. This work confirms COSMO-RS as a valuable tool for solvent selection and demonstrates that UAE with the identified DES provides an efficient, greener approach for extracting valuable benzopyrans, offering a foundation for further process optimization.