Jiangxi Key Laboratory of Natural Product and Functional Food, College of Food Science and Engineering, Jiangxi Agricultural University , Nanchang 330045, China.
J Agric Food Chem. 2013 Dec 11;61(49):12085-91. doi: 10.1021/jf404420s. Epub 2013 Nov 25.
The influence of temperature, pH value, and solvent on the degradation behavior of astilbin was studied by HPLC. Results showed that the degradation of astilbin was pH and temperature dependent, and the isomerization of astilbin to its three stereoisomers was found. The degradation process followed the first-order kinetics model, and the degradation rate k values increased, whereas half-life (t1/2) values declined with the rise of pH and temperature. The stability of astilbin was related to its B-ring substitution. Engeletin with a 4'-hydroxy-substituted B-ring was more stable than astilbin with a 3',4'-dihydroxy-substituted B-ring. The stability of astilbin differed depending on the solvent and followed the order 50% ethanol > ethanol > methanol > 50% methanol > water. In cultural media, astilbin was less stable than in water, which may be related to the presence of metal ions. The stability results of astilbin were confirmed in the extraction of dihydroflavonols from Rhizoma Smilacis Glabrae and may have a guiding function in turtle jelly production.
采用高效液相色谱法研究了温度、pH 值和溶剂对紫云英苷降解行为的影响。结果表明，紫云英苷的降解受 pH 值和温度的影响，发现紫云英苷异构化为其三个立体异构体。降解过程遵循一级动力学模型，降解速率 k 值增加，而半衰期（t1/2）值随着 pH 值和温度的升高而下降。紫云英苷的稳定性与其 B 环取代基有关。具有 4'-羟基取代的 B 环的勒比琴苷比具有 3',4'-二羟基取代的 B 环的紫云英苷更稳定。紫云英苷的稳定性取决于溶剂，其稳定性顺序为 50%乙醇>乙醇>甲醇>50%甲醇>水。在培养基中，紫云英苷不如在水中稳定，这可能与金属离子的存在有关。紫云英苷的稳定性结果在菝葜中二氢黄酮醇的提取中得到了证实，这可能对龟苓膏的生产具有指导作用。
