栀子药材中西红花苷-1的化学稳定性研究

Study on the stability of crocin-1 of Fructus Gardenniae

目的利用化学动力学原理,定量考察了栀子药材中西红花苷-1在不同条件下的反应速率常数及化学动力学模型与方程,探讨了影响栀子中西红花苷-1化学稳定性的主要因素。方法采用化学动力学原理及方法,以ln(Ct/C0)为纵坐标,时间为横坐标,绘制栀子中西红花苷-1的反应动力曲线,并得到动力学方程。其中反应动力曲线的斜率即为栀子中西红花苷-1在该条件下的化学动力学速率常数K,可根据t1/2=0.692/K计算栀子中西红花苷-1的半衰期。结果溶液的p H、光照基本对栀子药材中西红花苷-1的稳定性几乎无影响。在高温(80℃)加热条件下,栀子中西红花苷-1会发生降解反应,其化学动力学反应为一级反应,根据阿累尼乌斯经验公式计算得到其活化能为62.44 k J/mol,半衰期为37.82h。结论栀子药材中西红花苷-1比较稳定性,仅在高温下发生降解。

Objective To investigate the chemical kinetics of crocin- 1 of Fructus Gardenniae in different conditions quantitatively and calculate the chemical kinetic parameters and equations in order to find out the major factors affecting the stability of crocin- 1 of Fructus Gardenniae. Methods The kinetic line was obtained by setting the ln（ Ct/ C0） as ordinate and making time as abscissa. The slope of the kinetic line was the reaction constant of crocin- 1 in such condition. The t1 /2was calculated by the equation t1 /2= 0. 692 / K. Results The influences of initial concentration,p H value,temperature and light on stability of crocin- 1 of Fructus Gardenniae were carried out,respectively. The results suggested the degradation of crocin- 1 of Fructus Gardenniae fitted the pseudo- first- order reaction. The chemical kinetics parameters including rates constant and half time of degradation in different conditions were obtained by the means of ln（ Ct/ C0） versus reaction time. The activation energy of crocin- 1 of Fructus Gardenniae were also available from the calculation of rate constants under different temperature according to the Arrhenius equation and was 62. 44 k J / mol. The t1 /2was 37. 82 h. Conclusion Crocin- 1 of Fructus Gardenniae is unstable in the high temperature,and is prone to degradation.