Solvent-based extraction optimisation for efficient ultrasonication-assisted ginsenoside recovery from Panax quinquefolius and P. sikkimensis cell suspension lines

The present study aims at developing an extraction protocol for efficient ginsenoside recovery from cell suspensions of Panax quinquefolius and P. sikkimensis. Methanol (100%, 70% and 30%), water (40°C, 90°C), water-saturated butanol and butanol-saturated water were compared for their ultrasonication-assisted ginsenoside retrieval efficacy. HPLC and HP-TLC analysis revealed 100% methanol as the best solvent for maximum retrieval of Rb (diol) and Rg (triol) ginsenosides (P. quinquefolius: Rb: 0.189, Rg: 3.163 mg/g DW; P. sikkimensis: Rb: 0.245, Rg: 4.073 mg/g DW), followed by water (90°C). Methanolic solutions, especially 70%, proved to be significant retrievers of Rg1 (1.812 and 1.327 mg/g DW in P. quinquefolius and P. sikkimensis), with poor Re recovery (0.328 and 0.342 mg/g DW). Water-saturated butanol also led to significant ginsenoside extraction (72.4% of content extracted by methanol), selectively in P. quinquefolius, with a less than 50% of total content extracted by methanol, in P. sikkimensis.