Vacuum-powered bubble-assisted solvent extraction followed by macroporous resin enrichment for isolation of podophyllotoxin from Sinopodophyllum emodi

• Podophyllotoxin was extracted by vacuum-powered bubble-assisted method.
• The efficiency in this work is higher than that of the conventional method.
• The proposed approach has eco-friendly, convenient, high practical value technique.
• Podophyllotoxin can be effectively enriched and separated by macroporous resin.

A vacuum-powered bubble-assisted solvent extraction (VBE) technique was used to extract podophyllotoxin from the root of Sinopodophyllum emodi. We optimized the VBE procedure and showed it had the highest efficiency of extraction compared to other conventional extraction techniques. Based upon the results of single-factor experiments, a three-factor, three-level experiment design was developed by application of a Box–Behnken design. The method was validated by stability, repeatability and recovery experiments. The optimal conditions were: solvent, 60% (v/v) ethanol; particle size of the sample, 60–80 mesh; soak time, 2 h; liquid/solid ratio, 21 L/kg; air flow, 32 mL/min; vacuum-powered bubble extraction time, 65 min. The VBE method we developed achieved efficient extraction of podophyllotoxin from S. emodi. The podophyllotoxin extracted can be enriched and separated by an HPD300 macroporous resin adsorption and desorption process. The results indicated that VBE is a convenient, rapid and efficient sample preparation technique.