Optimization of extraction parameters of pentacyclic triterpenoids from Swertia chirata stem using response surface...

In the present investigation, pentacyclic triterpenoids were extracted from different parts of Swertia chirata by solid-liquid reflux extraction methods. The total pentacyclic triterpenoids (UA, OA, and BA) in extracted samples were determined by HPTLC method. Preliminary studies showed that stem part contains the maximum pentacyclic triterpenoid and was chosen for further studies. Response surface methodology (RSM) has been employed successfully by solid-liquid reflux extraction methods for the optimization of different extraction variables viz., temperature (X₁ 35-70 °C), extraction time (X₂ 30-60 min), solvent composition (X₃ 20-80%), solvent-to-solid ratio (X₄ 30-60 mlg^-1), and particle size (X₅ 3-6 mm) on maximum recovery of triterpenoid from stem parts of Swertia chirata. A Plackett-Burman design has been used initially to screen out the three extraction factors viz., particle size, temperature, and solvent composition on yield of triterpenoid. Moreover, central composite design (CCD) was implemented to optimize the significant extraction parameters for maximum triterpenoid yield. Three extraction parameters viz., mean particle size (3 mm), temperature (65 °C), and methanol-ethyl acetate solvent composition (45%) can be considered as significant for the better yield of triterpenoid A second-order polynomial model satisfactorily fitted the experimental data with the R² values of 0.98 for the triterpenoid yield (p < 0.001), implying good agreement between the experimental triterpenoid yield (3.71%) to the predicted value (3.79%).