Abstract

Phillyrin is an abundant naturally occurring lignan, which makes it a potentially important raw material for a precursor of biologically active compounds. The objective of the current study was to optimize the extraction conditions for phillyrin from Forsythia suspensa. The optimum conditions were evaluated with preliminary experiments and optimized using response surface methodology. Statistical analysis of results showed that the linear and quadric terms of these four variables had significant effects, and evident interaction existing between extraction time and extraction temperature was also found to contribute to the response at a significant level. The extraction conditions were further investigated with Box-Behnken design. The fitted second-order model revealed that the optimal conditions consisted of methanol concentration of 21.17%, extraction time 85.43 min, extraction temperature 66.81°C and ratio of liquid to material 11.2. Under the optimized condition, the experimental value of 0.801±0.012 mg/g was well in close agreement with the value predicted by the model. Moreover, the yield of phillyrin in the condition was higher than that of the non-optimized condition. These results help in designing the process of optimal phillyrin from F. suspensa.

Key words: Forsythia suspensa, phillyrin, optimum conditions, response surface methodology; box-behnken design.