Simultaneous Determination of Honokiol and Magnolol in Magnolia Officinalis by Capillary Zone Electrophoresis

A simple and rapid capillary electrophoretic method was developed for the simultaneous determination of honokiol and magnolol in Magnolia officinalis extracts and dextrorphan was used as the internal standard. The running buffer was composed of 22.5 mM Na2HPO4 and 10 mM Na2B4O7 (pH 9.1–9.2). The linear calibration range was 2 – 20 μg/mL for honokiol and 5–50 μg/mL for magnolol. It was found that 0.95 ±0.02 mg of honokiol and 4.37 ± 0.08 mg of magnolol were contained in the ethanol (50%) extracts of 1 g of Magnolia officinalis. The contents of these two active principles in Magnolia officinalis was successfully determined within 12 min.