Target-oriented rational design of composite bio-derived solvents for the green extraction of salvianolic acid B and tanshinones from Salvia miltiorrhiza root

Finding sustainable and efficient ways to extract natural products is becoming increasingly important for both the pharmaceutical and food industries. In this study, we propose a target-oriented approach for the rational design of composite bio-derived solvents, specifically tailored for the simultaneous extraction of salvianolic acid B, tanshinone I, cryptotanshinone and tanshinone IIA from Salvia miltiorrhiza root. We systematically evaluated the extraction efficiency of various bio-derived solvents, including glycerol carbonate, ethylene glycol, levulinic acid, glycerolformal, ethyl lactate and γ-valerolactone, both individually and in combination. Using a mixture design integrated with statistical modeling and optimization algorithms, we identified that the composite solvent system of GF/LA (57.8/42.2, v/v) greatly improved the extraction of both hydrophilic and lipophilic compounds. The extraction yields were significantly higher compared to those obtained using individual bio-derived or traditional solvents, while the overall solvent consumption was lower. Additionally, we explored the use of macroporous adsorption resins to recover the extracted compounds from GF/LA (57.8/42.2, v/v) extracts solution, achieving impressive recovery yields of over 80%. Our findings provide valuable insights into the sustainable extraction of bioactive compounds and suggest practical applications for both analytical and industrial-scale processes, aligning with green chemistry principles.