Investigation of Stability of Lactones in Volatile Oil from Chuanxiong Rhizoma

Abstract:

Objective: To invesitgate stability of lactones in volatile oil from Chuanxiong Rhizoma. Method: The content of ligustilide at different times was determined by HPLC when volatile oil was put in refrigeration(4℃) avoiding light, room temperature(18-25℃) avoiding light and room temperature under light,respectively.degradation rate constant of ligustilide was calculated,chromatographic conditions were as follows:Hedera ODS-2 column(4.6 mm×250 mm,5 μm),mobile phase of methanol-water(65:35),detection wavelength 273 nm,column temperature 30℃,injection volume 10 μL,flow rate 1 mL·min^-1.And analyzed peak area change of butylphthalide,3-butylidenephthalide and senkyunolide A at the same concentration. Result: Under these three conditions,degradation rate constants of ligustilide in volatile oil were 2.0×10^-4,6.4×10^-3,8.4×10^-3,respectively;With extension of storage time,contents of butylphthalide and 3-butylidenephthalide increased while ligustilide and senkyunolide A decreased,and increasing amplitude of 3-butylidenephthalide was close to reduction amplitude of ligustilide. Conclusion: Volatile oil from Chuanxiong Rhizoma should be stored below 4℃ avoiding light,and its components could transform into each other during storage.