Experimental and simulative studies on the implications of natural and green surfactant for extracting flavonoids

In the era of green chemistry, natural and sustainable extraction solvents have become the focus of people's attention in the process of extracting target compounds from plants. In this work, a novel surfactant based synergistic negative pressure cavitation extraction (NPCE) technique assisted with the natural surfactant tea saponin (TS) was firstly developed for extracting seven target flavonoids (STF) from Hibiscus manihot L. flower (HMLF) simultaneously. After systematical experimental screening, the ideal experimental parameters (extraction solvent: 60% ethanol containing 0.5% (w/v) TS, negative pressure: 0.07 MPa, liquid solid ration: 53 mL/g, extraction temperature: 61 degrees C, extraction time: 16 min) were optimized, and the maximum total extraction yield of STF of 19.80 mg/g in the solvent system. In addition, the TS extraction solution could be recycled for at least three runs with the extraction efficiency and recovery of 18.96-14.84 mg/g and 77.84-87.03%, respectively. Moreover, the synergistic extraction mechanism of natural surfactant TS and NPCE on the efficient extraction of quercetin and other flavonoids from HMLF was illuminated by molecular docking, and FTIR verification showed the formation of H-bonds between TS and target flavonoid molecules. In conclusion, surfactant-negative pressure cavitation extraction (S-NPCE) technique conforms to the concept of green chemistry, which possesses the potential as a remarkably simple and valid alternative for the extraction of natural products from plant materials. (c) 2020 Elsevier Ltd. All rights reserved.