Abstract:

Response surface methodology was employed to optimize the extraction of flavonoids from young leaves and stems of wild Gypsophila oldhamiana Miq. collected from Huaguo Mountain region in Lianyungang with the aim of developing a generalized approach for sample preparation for the determination of flavonoids in other botanical parts of this plant. A quadratic regression model that describes extraction efficiency as a function of temperature, time and solvent-to-solid ratio was established using a Box-Behnken experimental design. The optimum extraction conditions were obtained as follows: two extraction cycles at 65 ℃ for 112 min each cycle with a solvent-to-solid ratio of 27:1 (mL/g). Under these conditions, the predicted flavonoid yield was 2.652% as opposed to 2.649% of the actual value. There was a considerable difference in flavonoid content among different botanical parts of Gypsophila oldhamiana Miq.: 5.264%, 2.983%, 2.145% and 1.861% in leaves, flowers, stems and roots, respectively.

Key words: Gypsophila oldhamiana Miq., flavonoids, extraction, response surface methodology (RSM)