Sustainable Extraction of Bioactive Compounds from <i>Annona muricata L.</i> Leaves by Deep Eutectic Solvents (DESs)

Soursop (<i>Annona muricata L.</i>) leaves are rich in bioactive compounds with promising pharmacological and food applications. Deep eutectic solvents (DESs), a class of green and tunable solvents, offer an efficient and sustainable alternative to their extraction. This study investigates the use of various DES formulations for extracting bioactive compounds from soursop leaves under optimized conditions, considering the temperature, solvent-to-biomass ratio, and extraction time in a solid-liquid system. Conventional techniques, such as magnetic stirring and ultrasonic bath extraction, were also evaluated for comparison. DESs were prepared using choline chloride and menthol as hydrogen bond acceptors (HBAs) combined with lactic acid, oxalic acid, and 1,2-propanediol as hydrogen bond donors (HBDs). The optimal extraction conditions were determined at 50 °C with a biomass-to-solvent ratio of 1:10 (m/v). Solvent performance and interactions with biomass were analyzed using NMR, FTIR, density, viscosity, pH, and total humidity assessments. Compared to water and ethanol, DESs exhibited superior efficiency and stability, enhancing cell wall disruption and improving extraction yields. Among the tested solvents, acidic DES (CCAO) demonstrated the highest extraction efficiency despite its high viscosity and density. These findings pave the way for future applications in the pharmaceutical and food industries, reinforcing DESs as a promising environmentally friendly alternative for the extraction of high-value bioactive compounds from plant biomass.