Towards efficient extraction of notoginseng saponins from cultured cells of Panax notoginseng

Different extraction methods including conventional organic solvent, Soxhlet, heat reflux, ultrasound-assisted and microwave-assisted extractions were attempted for efficient extraction of notoginseng saponins from dried cells of Panax notoginseng obtained in bioreactor cultures. The microwave-assisted extraction for 6 min led to a similar saponin yield (based on mg/100 mg cells) compared to other methods that took 2–14 h. To optimize the microwave-assisted extraction conditions, the treatment time, temperature, solid/liquid (w/v) ratio and the number of repeated extraction steps were further studied. The optimal extraction method was microwave-assisted extraction for 4 min of extraction time at 50 °C of extraction temperature (at a radiation power of 125 W) and 1:150 of the solid/liquid (w/v) ratio. The yield of total saponins extracted from P. notoginseng cells was increased with an increase of extraction steps, and it was obtained more with microwave assistance than that without microwave assistance.