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目的研究木犀草素-7-O-β-D葡萄糖醛酸苷(luteotin-7-O-β-D glucuronide,LGU)的水解动力学特征。方法采用HPLC-UV法测定LGU在初始质量浓度0.1~0.3 g·L-1、p H值2~10和温度60~90℃各条件下随时间变化而发生的质量浓度变化,计算各水解动力学参数。结果 LGU水解反应符合伪一级动力学方程。其水解速率与起始浓度无关但随着温度的升高而增加。LGU在碱性或强酸性条件下不稳定,在p H值为4左右最稳定。LGU在p H值为6磷酸缓冲溶液的水解反应活化能估算为76.25 k J·mol-1,在25℃下LGU水解掉10%的时间t0.9为73.8 d。结论 LGU水解属于伪一级降解反应,p H值和温度对LGU稳定性影响较大。
Objective To investigate the kinetic characteristics of hydrolysis of luteotin-7-O-β-D glucuronide (LGU). Methods The changes of mass concentration of LGU with time under the initial concentration of 0.1-0.3 g · L-1, p H value 2-10 and temperature of 60-90 ℃ were determined by HPLC-UV method. Learning parameters. Results The LGU hydrolysis reaction was in accordance with pseudo first-order kinetic equation. The rate of hydrolysis has nothing to do with the initial concentration but increases with increasing temperature. LGU is unstable under alkaline or strongly acidic conditions and is most stable at a pH of about 4. The activation energy of hydrolysis of LGU at pH 6 phosphate buffer solution was estimated to be 76.25 kJ · mol-1, and the time t0.9 at 10% LGU hydrolysis at 25 ° C was 73.8 days. Conclusion The hydrolysis of LGU belongs to pseudo-first-order degradation reaction, and p H value and temperature have a great influence on the stability of LGU.