Objective: To study the scientific evidence of the traditional preparation of Dachengqi: "Boiling Aurantii Immaturus and Magnoliae Officinalis first, and then adding Rhei to decoct together. Discarding the dregs, adding Natrii Sulfas into the decoction and drinking the upper solution when the Natrii Sulfas has dissolved completely".
Method: The concentrations of free and combined anthraquinonoids(emodin, rhein, chrysophanol, physcion) in different decoctions were determined with HPLC method respectively.
Result: When Natrii Sulfas, Aurantii Immaturus and Magnolias Officinalis are decocted with Rhei in different schemes, the concentrations of anthraquinonoids were changed regularly.
Conclusion: The scientific evidence of traditional preparation method greatly increased the concentrations of the active components in Dachengqi.