Optimized extraction of secoiridoid glycosides from Gentianae radix by pressurized liquid extraction using a Box–Behnken Design

Abstract

AbstractIn this study, a Box–Behnken design was used to optimize experimental conditions for the pressurized liquid extraction of three secoiridoid glycosides (swertiamarin, gentiopicroside, and trifloroside) from Gentianae radix. Optimal conditions for the pressurized liquid extraction were determined through a carefully designed optimization process comprising two distinct stages: a single‐factor experiment followed by a Box–Behnken design. The optimized conditions involve a single 18‐min extraction cycle using 61% aqueous ethanol and a 3/5 (g/g) ratio of Gentianae radix to diatomite. High‐performance liquid chromatography was used to determine experimental yields, which were consistent with the predicted values under optimized conditions. Consistently high yields over short extraction times were achieved with the optimized pressurized liquid extraction conditions, as compared to the results of comparative ultrasound‐assisted and Soxhlet extractions. The results demonstrate the multiple advantages of pressurized liquid extraction for the extraction of secoiridoid glycosides from Gentianae radix: reduced extraction times, convenient setup, and high extraction efficiency.