[Qualitative and quantitative methods of betulonic acid in fruits of Liquidambar formosana].

Objective: To develop the identification and assay methods for betulonic acid in fruits of Liquidambar formosana.

Method: TLC method was used for identification with silica gel G plate and petroleum ether(60-90 degrees C)-acetone (17:3) as a developing solvent. Betulonic acid in ethanol extract was separated on the ODS column with methanol-water-glacial acetic acid (87:13:0.1) as mobile phase. Flow-rate was 1.0 mL x min(-1), and column temperature 35 degrees C. ELSD drift-tube temperature was 82 degrees C, and gas flow 1.25 L x min(-1).

Result: The qualitative method is repeatable. Betulonic acid in ethanol extracts is well separated, relationship of logarithms of injection amount and peak area is linear (r = 0.9997) within the range of 0.65-3.25 microg. The average recovery is 98.0% and RSD of repeatability is 2.5%. 11 crude drugs purchased from different areas in the country were identified and quantified with the methods.

Conclusion: The methods and data could be used for quality control of fruits of L. formosana.