Pressurized liquid extractions were performed on a Dionex
ASE 200 (Dionex Corp., Sunnyvale, CA, USA) system.
In brief, raw materials of Ezhu were dried at 40 ◦C for
6 h and was ground into powder of 0.2–0.3 mm. Powder
of Ezhu (2.5 g) was mixed with diatomaceous earth (2.5 g)
and placed into 11 ml stainless-steel extraction cell, respectively. The sample was extracted under the optimized conditions: solvent, methanol; temperature, 120 ◦C; particle size,
0.2–0.3 mm; static extraction time, 5 min; pressure, 1500 psi;