HPLC analysis of magnolol and honokiol in Magnoliae Cortex after solvent sublation

Summary

A novel method for separating and concentrating magnolol and honokiol from Magnoliae Cortex by solvent sublation and analysis of the compounds by high-performance liquid chromatography (HPLC) has been established. The optimum conditions for solvent sublation were use of n-butanol as sublation solvent, sample solution at pH 2, nitrogen flow 50 mL min ^–1, and sublation time 50 min. The floating product obtained under the optimum conditions was determined by HPLC analysis on a C ₁₈ reversed-phase column, with 22:78 (%, v/v) water-methanol as isocratic mobile phase at a flow rate of 1.00 mL min ^–1. When the method was used for quantification of magnolol and honokiol in Magnoliae Cortex recovery ranged from 98.1 to 106.1%, RSD was from 3.07 to 4.80%, and LOD for honokiol and magnolol were 0.94 and 1.14 ng mL ^–1, respectively.