Supercritical CO 2 Assisted Extraction and LC–MS Identification of Picroside I and Picroside II from Picrorhiza kurroa

Picroside I and picroside II have been studied intensively because of their pharmacological actions and clinical applications. Numerous methods have been reported for extracting picroside I and picroside II from Picrorrhiza. kurroa rhizomes. This is the first report of picroside I and picroside II extraction using the supercritical carbon dioxide assisted extraction technique. Objective To develop supercritical carbon dioxide assisted extraction and LC–MS identification of picroside I and picroside II from the Picrorrhiza kurroa Royle rhizomes. Methodology Surface response methodology based on 3 3 fractional factorial design was used to extract picroside I and picroside II from P. kurroa rhizomes. The effects of various process factors, namely temperature (40–80°C), pressure (25–35 MPa) and co‐solvent (methanol) concentration (0–10% v/v) on extraction yield of the two compounds were evaluated. The picroside I and picroside II contents were determined using validated LC–MS methodology. Results The maximum yield of picroside I (32.502 ± 1.131 mg/g) and picroside II (9.717 ± 0.382 mg/g) was obtained at the 10% v/v co‐solvent concentration, 40°C temperature and 30 MPa pressure. The conventional Soxhlet assisted methanol extract of P. kurroa powder resulted in 36.743 ± 1.75 and 11.251 ± 0.54 mg/g yield of picroside I and picroside II, respectively. Conclusion Variation of concentration and extraction time showed a significant effect on the picroside I and picroside II yield. Supercritical carbon dioxide assisted extraction using methanol as a co‐solvent is an efficient and environmentally sustainable method for extracting picroside I and picroside II from P. kurroa rhizomes. Copyright © 2012 John Wiley & Sons, Ltd.