Mechanochemical-Assisted Extraction of Active Alkaloids from Plant with Solid Acids

In this work, a novel mechanochemical-assisted extraction (MCAE) coupled with the ultra-high performance liquid chromatography (UHPLC) method was developed to extract two alkaloids with solid acids from Stephania tetrandra S. Moore. To further understand the influence of extraction parameters on the MCAE process, the response surface methodology was applied for systematic investigation. The results showed that the highest yield of alkaloids was obtained within 15 min of the total extraction time under the optimal conditions: oxalic acid (20 wt %), grinding plant materials for 5 min, and the liquid/solid ratio of 20 mL/g. Mechanochemical treatment resulted in the destruction of cell walls and increased the total contact surface area due to the smooth surface changing to an open porous structure. Accordingly, the developed extraction method showed advantages of being more ecofriendly, faster, and more efficient than conventional extraction methods. Meanwhile, the extractant was analyzed by UHPLC. The obtained LODs for fangchinoline and tetrandrine were 0.013 and 0.012 μg/mL and good linearity with correlation coefficient of determination higher than 0.9991. Moreover, spiked recoveries were in the range of 101.03%–103.81%. This proves that mechanochemistry processing provides a sensitive, highly effective, and environmentally friendly method