Comparison of Four Methods of Extraction of Magnolol and Honokiol in Chinese Patent Drugs

Objective:To compare the influences of four kinds of extraction methods in current standard of proprietary Chinese medicines on the determination of magnolol and honokiol content.Method: The samples were extracted by petroleum ether and methanol using ultrasonic extraction or Soxhlet extraction;determination was performed by HPLC.The column was Kromasil C18(4.6 mm × 250 mm,5 μm),water-acetonitrile-acetic acid(60∶38∶2) was used as mobile phase;UV detection was at 294 nm.Result:The content of magnolol and honokiol with ultrasonic extraction by methanol was higher than Soxhlet extraction by methanol,and the Soxhlet extraction by methanol was higher than Soxhlet extraction by petroleum ether and ultrasonic extraction in the recovery aspects.he ratio of honokiol to magnolol in samples was 0.304-2.669.Conclusion:The ultrasonic extraction by methanol for the determination was the optimal extraction methods.The different ratio of honokiol to magnolol was due to the different ingredients from different source.